BOARD-INVITED REVIEW: Intrauterine growth retardation: Implications for the animal sciences1

Intrauterine growth restriction in newborn piglets associated with piglet characteristics, colostrum intake, litter size and parity number in prolific sows

The genetic selection of highly prolific sows has increased the number of fetuses within the uterus, directly affecting piglet quality due to limited placental space. This results in placental insufficiency and fetal intrauterine growth restriction (IUGR). This study aimed to investigate the incidence of IUGR in newborn piglets within a commercial swine herd under tropical conditions and to examine its association with piglet characteristics, birth order, litter size, sow parity, colostrum intake, and mortality rate during the first 24 h of life. The experiment was conducted in a commercial swine herd in Thailand. Data were collected from 114 litters of French Landrace × Yorkshire crossbred sows. Immediately after birth, the degree of IUGR was determined in 1868 piglets, comprising 1743 live-born and 125 stillborn piglets. Sows were categorized into four groups based on parity number: 1 (n = 28), 2 (n = 34), 3-5 (n = 33), and 6-8 (n = 19). Litters were further classified by total litter size into three categories: 7-14 (n = 18), 15-19 (n = 51), and ≥20 piglets (n = 45). On the day of parturition, IUGR was visually assessed in both live-born and stillborn piglets. Various farrowing and piglet parameters were recorded, including farrowing duration and litter traits. Birth weight was measured before and after colostrum ingestion, and individual colostrum intake was calculated. The incidence of IUGR in newborn piglets was 16.2 % (302/1868 piglets), with moderate and severe IUGR observed in 10.8 % and 5.4 % of piglets, respectively. The percentage of IUGR piglets in litters with 7-14 piglets (8.5 %) was lower than in litters with 15-19 piglets (17.1 %, P = 0.008) and ≥20 piglets (17.2 %, P = 0.005). IUGR piglets exhibited significantly lower birth weights (832 ± 28.6 g vs. 1274 ± 16.8 g, P < 0.001) compared to normal piglets. They also consumed less colostrum (257.1 ± 14.2 g vs. 414.3 ± 7.4 g, P < 0.001) and had a higher percentage of individuals with insufficient colostrum intake (<300 g) (77.3 % vs. 27.6 %, P < 0.001). At 24 h postpartum, IUGR piglets exhibited lower rectal temperatures (37.7 ± 0.1 vs. 38.1 ± 0.1 °C, P < 0.001) compared to normal piglets. Additionally, IUGR piglets experienced a higher mortality rate within the first 24 h of life compared to normal piglets (18.5 % vs. 6.1 %, P < 0.001). In conclusion, the results demonstrate that IUGR piglets exhibit lower birth weights, reduced colostrum intake, and poorer thermoregulation. These factors contribute to the higher mortality rate observed in IUGR piglets compared to their normal counterparts. Moreover, the proportion of IUGR piglets increases with larger litter sizes, emphasizing the impact of uterine crowding. This study underscores the importance of managing sow productivity to minimize the prevalence of IUGR and improve piglet survival and welfare.

Subchronic Exposure to Polystyrene Nanoplastics Disrupts Placental Development and Calcium Homeostasis: Insights from In Vivo and In Vitro Models

Nanoplastics have recently emerged as persistent pollutants of global concern that pose substantial risks to human health. However, the long-term adverse effects of nanoplastics on the female reproductive system remain unclear. Polystyrene nanoplastics (PS-NPs; 50 nm diameter) were selected as representative nanosized plastic particles to investigate the potential effects of subchronic prenatal and gestational exposure via drinking water on placental development in ICR (CD-1) mice. Maternal exposure to 10 mg/L PS-NPs induced an increase in fetal resorption rate and significantly increased fetal weight. Further observation of the placental morphology showed that PS-NPs exposure led to an aberrant placental structure and damaged the trophoblast cells. At the cellular level, PS-NPs exposure promoted the proliferation, migration, and invasion of HTR-8/SVneo cells. Mechanistically, transcriptomic and proteomic analyses revealed that PS-NPs triggered placental calcium disturbances and upregulated the Stam2 expression in mice. STAM2 induced by PS-NPs mediates the disruption of trophoblastic calcium homeostasis and regulates cell functions by disturbing the lysosomal degradation of the calcium channel protein IP3R3 and promoting intracellular calcium inflow by increasing the level of TRPV6 in HTR-8/SVneo cells. Therefore, our results indicated that trophoblastic calcium dyshomeostasis is the main mechanism by which subchronic PS-NPs exposure induces abnormal placental development. These findings reveal a link between subchronic PS-NPs exposure and placental damage and elucidate the underlying molecular mechanism, providing evidence for environmental triggers of adverse pregnancy and highlighting the risk of plastic products to pregnant women.

Impacts of prenatal nutrition on metabolic pathways in beef cattle: an integrative approach using metabolomics and metagenomics

BACKGROUND

This study assessed the long-term metabolic effects of prenatal nutrition in Nelore bulls through an integrated analysis of metabolome and microbiome data to elucidate the interconnected host-microbe metabolic pathways. To this end, a total of 126 cows were assigned to three supplementation strategies during pregnancy: NP (control)- only mineral supplementation; PP- protein-energy supplementation during the last trimester; and FP- protein-energy supplementation throughout pregnancy. At the end of the finishing phase, blood, fecal, and ruminal fluid samples were collected from 63 male offspring. The plasma underwent targeted metabolomics analysis, and fecal and ruminal fluid samples were used to perform 16 S rRNA gene sequencing. Metabolite and ASV (amplicon sequence variant) co-abundance networks were constructed for each treatment using the weighted gene correlation network analysis (WGCNA) framework. Significant modules (p ≤ 0.1) were selected for over-representation analyses to assess the metabolic pathways underlying the metabolome (MetaboAnalyst 6.0) and the microbiome (MicrobiomeProfiler). To explore the metabolome-metagenome interplay, correlation analyses between host metabolome and microbiome were performed. Additionally, a holistic integration of metabolic pathways was performed (MicrobiomeAnalyst 2.0).

RESULTS

A total of one and two metabolite modules associated with the NP and FP were identified, respectively. Regarding fecal microbiome, three, one, and two modules for the NP, PP, and FP were identified, respectively. The rumen microbiome demonstrated two modules correlated with each of the groups under study. Metabolite and microbiome enrichment analyses revealed the main metabolic pathways associated with lipid and protein metabolism, and regulatory mechanisms. The correlation analyses performed between the host metabolome and fecal ASVs revealed 13 and 12 significant correlations for NP and FP, respectively. Regarding the rumen, 16 and 17 significant correlations were found for NP and FP, respectively. The NP holistic analysis was mainly associated with amino acid and methane metabolism. Glycerophospholipid and polyunsaturated fatty acid metabolism were over-represented in the FP group.

CONCLUSIONS

Prenatal nutrition significantly affected the plasma metabolome, fecal microbiome, and ruminal fluid microbiome of Nelore bulls, providing insights into key pathways in protein, lipid, and methane metabolism. These findings offer novel discoveries about the molecular mechanisms underlying the effects of prenatal nutrition.

CLINICAL TRIAL NUMBER

Not applicable.

Utero-placental adaptations in response to intrauterine growth restriction in swine

Intrauterine growth restriction (IUGR) is a common condition in swine associated with high piglet mortality and morbidity that develops in early gestation. This review article explores differences in uterine and placental tissues associated with IUGR fetuses compared to their normally-grown littermates at different stages of gestation. Specifically, we will review the available knowledge to date describing differences in 1) structure, 2) cellular apoptosis and proliferation, 3) adhesion, and 4) angiogenesis in endometrial and placental tissues associated with IUGR fetuses across gestation. Improved understanding of the mechanisms regulating IUGR is essential for the development of strategies to minimize the impact of IUGR in swine operations, thus improving reproductive efficiency and animal welfare.

Metabolome and transcriptome profiling reveal tRNA-derived small RNAs regulated glutathione metabolism in intrauterine growth-restricted pigs

Intrauterine growth retardation (IUGR) has become a difficult problem in animal husbandry and is often accompanied by the occurrence of metabolic syndrome. tRNA-derived small RNAs (tsRNAs) are a novel class of regulatory small noncoding RNAs. However, the involvement of tsRNA in regulating the mechanism of IUGR remains unclear. Here, we first characterized the tsRNA expression profiles in the liver of normal pigs and IUGR pigs through high-throughput sequencing. IUGR pigs exhibit significantly increased 17 tsRNA levels including tRF-Ile-GAT, tRF-Pro-TGG, tRF-Leu-CAA and tRF-Ala-TGC etc. Transcriptome sequencing further revealed 1244 upregulated and 762 downregulated differentially expressed genes in IUGR pig liver. Functional enrichment analysis found that DEGs were mainly involved in insulin resistance, metabolic pathways, etc. Metabolomics was performed to determine the metabolic changes between the normal and IUGR pigs. Then, We constructed a potential tsRNA regulatory network involved in metabolic pathways in IUGR pig liver. Moreover, combined metabolome and transcriptome analysis showed a disorder of glutathione metabolism in the IUGR pigs liver. We identified tRF-Ile-GAT as the potential target of interest. NCTC1469 liver cells were used to validate the preliminary function of tRF-Ile-GAT in vitro. Bioinformatics analyses and luciferase reporter assays further revealed that microsomal glutathione S-transferase 1 (MGST1) was the target gene of tRF-Ile-GAT. In addition, tRF-Ile-GAT overexpression inhibited antioxidant gene expression, glutathione and glutathione glutathione S-transferase levels in NCTC1469 cells, while an MGST1 overexpression reversed the above phenomenon. These findings provide new insights into the understanding of the molecular mechanisms of IUGR pathogenesis.

Increased proline intake during gestation alleviates obesity-related impaired fetal development and placental function in gilts

Maternal proline (Pro) supplementation enhances fetal survival and placental development in mice. However, the effect of Pro on fetal and placental development in gilts remains to be investigated, particularly in the context of obesity-induced impaired pregnancy. Here, we investigated the effect of dietary Pro on fetal and placental development in obese gilts. Exp.1: On day 60 of gestation, 48 gilts with similar delivery times were selected and followed up until delivery to determine the relationship between maternal obesity, litter performance, and Pro abundance in term placentae. The results showed that impaired reproductive performance was associated with body condition parameters and inadequate placental Pro availability of gilts. Exp. 2: A total of 114 gilts were then used in a 2 × 3 factorial design to investigate the interaction between body condition (factor I: normal or obese gilts) and dietary Pro levels (factor II: low [0.89%, L-Pro], medium [1.39%, M-Pro], and high [1.89%, H-Pro]) on farrowing performance and placental angiogenesis. This resulted in six treatment combinations: normal-L-Pro, obese-L-Pro, normal-M-Pro, obese-M-Pro, normal-H-Pro, and obese-H-Pro. The effective number of replicates per group was 17, 21, 19, 21, 18, and 18, respectively (1 gilt per replicate). The results showed that increasing Pro intake increased piglet birth weight (P = 0.001), litter weight (P < 0.001), placental efficiency (P = 0.036) and placental vascular density (P < 0.001), and decreased the number of mummified fetuses (P = 0.001), the rate of low-birth-weight piglets (P = 0.005), and the rate of invalid piglets (P = 0.029). Interaction effects were observed between body condition and dietary Pro levels on piglet birth weight (P = 0.046), within-litter birth weight variation (P = 0.012), and placental vascular density (P = 0.007). Moreover, the beneficial effect of Pro on farrowing performance may be related to the improvement of sirtuin 1-superoxide dismutase 2-mitochondrial reactive oxygen species axis homeostasis and angiogenesis in the placenta. Our results suggest that gestation diets need to provide adequate Pro to meet the needs of fetal and placental development, particularly in obese gilts.

Intrauterine growth restriction, defined by an elevated brain-to-liver weight ratio, affects faecal microbiota composition and, to a lesser extent, plasma metabolome profile at different ages in pigs

BACKGROUND

Intrauterine growth restriction (IUGR) affects up to 30% of piglets in a litter. Piglets exposed to IUGR prioritize brain development during gestation, resulting in a higher brain-to-liver weight ratio (BrW/LW) at birth. IUGR is associated with increased mortality, compromised metabolism, and gut health. However, the dynamic metabolic and microbial shifts in IUGR-affected pigs remain poorly understood. This study aimed to investigate the longitudinal effects of IUGR, defined by a high BrW/LW, on the composition of faecal microbiota and plasma metabolome in pigs from birth to slaughter. One day (± 1) after birth, computed tomography was performed on each piglet to assess their brain and liver weights. The pigs with the highest (IUGR = 12) and the lowest (NORM = 12) BrW/LW were selected to collect faeces and blood during lactation (day 16 ± 0.6, T1) and at the end of the starter period (day 63 ± 8.6, T2) and faeces at the beginning (day 119 ± 11.4, T3) and end of the finisher period (day 162 ± 14.3, T4).

RESULTS

Faecal microbial Alpha diversity remained unaffected by IUGR across all time points. However, the Beta diversity was influenced by IUGR at T1 (P = 0.002), T2 (P = 0.08), and T3 (P = 0.03). Specifically, IUGR pigs displayed higher abundances of Clostridium sensu stricto 1 (Padj = 0.03) and Romboutsia (Padj = 0.05) at T1, Prevotellaceae NK3B31 group (Padj = 0.02), Rikenellaceae RC9 gut group (Padj = 0.03), and Alloprevotella (Padj = 0.03) at T2, and p-2534-18B5 gut group (Padj = 0.03) at T3. Conversely, the NORM group exhibited higher abundances of Ruminococcus (Padj = 0.01) at T1, HT002 (Padj = 0.05) at T2, and Prevotella_9 (Padj < 0.001) at T3. None of the plasma metabolites showed significant differences at T1 between the IUGR and NORM pigs. However, at T2, asparagine was lower in the IUGR compared to the NORM group (P < 0.05).

CONCLUSIONS

These findings show that growth restriction in the uterus has a significant impact on the faecal microbiota composition in pigs, from birth to the beginning of the finisher period, but minimally affects the plasma metabolome profile.

Oral Administration of L-Arginine Improves the Growth and Survival of Sow-Reared Intrauterine Growth-Restricted Piglets

Neonatal piglets with intrauterine growth restriction (IUGR) exhibit reduced rates of growth and survival. The present study tested the hypothesis that L-arginine supplementation can mitigate this problem. One hundred and twelve (112) IUGR piglets (with a mean birth weight of 0.84 kg) from 28 sows (four IUGR piglets/sow) were assigned randomly into one of four groups. Piglets were nursed by sows and orally administered 0, 0.1, 0.2, or 0.4 g L-arginine (in the form of L-arginine-HCl) per kg body weight (BW) twice daily between 0 and 14 days of age. The total doses of L-arginine were 0, 0.2, 0.4, or 0.8 g/kg BW/day. Appropriate amounts of L-alanine were added to L-arginine solutions so that all groups of piglets received the same amount of nitrogen. Piglets were weighed on days 0, 7, and 14 of age. On day 14, blood samples (5 mL) were obtained from the jugular vein of piglets at 1 h after suckling, and their milk consumption was measured over a 10-h period using the weigh-suckle-weigh technique. Milk intake did not differ (p > 0.05) among the four groups of piglets. Oral administration of 0.4 g L-arginine/kg BW/day increased (p < 0.05) the circulating levels of arginine, creatine, and anabolic hormones (insulin, growth hormone, and insulin-like growth factor-I), but decreased (p < 0.05) plasma concentrations of ammonia and cortisol (a catabolic hormone). Compared to the control group, IUGR piglets administered 0.2 and 0.4 g L-arginine/kg BW/day increased (p < 0.05) weight gain by 19% and 31%, respectively. Growth did not differ (p > 0.05) between the control and 0.8 g L-arginine/kg BW/day groups. The survival rates of IUGR piglets were 50%, 75%, 89%, and 89%, respectively, for the 0, 0.2, 0.4, and 0.8 g L-arginine/kg BW/day groups. Collectively, these results indicate that the growth and survival of IUGR piglets can be improved through L-arginine supplementation.

Intergenerational effects of maternal rate of body weight gain on the multi-omics hepatic profiles of bovine fetuses

Maternal periconceptual nutrition affects the growth trajectory of developing fetuses by modulating gene expression. The regulatory mechanisms and their role in fetal development remain underexplored in livestock models. Herein, we investigated the effects of maternal rate of body weight (BW) gain during early gestation on the DNA methylation, microRNA profiles, and their interaction with the hepatic gene expression in female fetuses. At breeding, 36 crossbred beef heifers (∼13 months of age) were randomly assigned to a nutritional plane to gain Low (0.28 kg/day; LG, n = 18) or Moderate (0.79 kg/day; MG, n = 18) BW through the first 83 days of gestation. A subset of pregnant heifers (n = 17) was selected, and fetal liver samples were collected on day 83 of gestation for DNA methylation and miRNA-Sequencing. After data quality control, miRDeep2 and Bismark tools were used to analyze miRNA and methylation data, respectively. The bta-miR-206 was the only differentially expressed miRNA (FDR = 0.02). Eight differentially methylated genes were identified (DMGs, FDR < 0.1). The over-represented pathways and biological processes (adj. p < 0.05) for bta-miR-206 targeted genes were associated with embryonic development, energy metabolism, and mineral transport, whereas the DMGs regulated anatomical structural development and transcriptional regulation. Our results show that key genes involved with liver metabolism, tissue structure, and function were regulated by DNA methylation and the miR-206. However, further investigation is warranted to determine physiological responses and long-term consequences on animal performance.

Maternal supplementation spermidine during gestation improves placental angiogenesis and reproductive performance of high prolific sows

Spermidine (SPD) is a widely recognized polyamine compound found in mammalian cells and plays a key role in various cellular processes. We propose that SPD may enhance placental vascular development in pregnant sows, leading to increased birth weight of piglets. Six hundred and nine sows at 60 days of gestation were randomly assigned into a basal diet (CON group), basal diet supplemented 10 mg/kg of SPD (SPD1 group), and basal diet supplemented 20 mg/kg of SPD (SPD2 group), respectively. Compared with the CON, SPD1 significantly increased the average number of healthy piglets per litter and the placental efficiency (P < .05), while the average number of mummified fetus per litter and the percentage of weak piglets significantly decreased (P < .05). In the plasma metabolomics, SPD content in plasma of sows (P = .075) and umbilical cord plasma of piglets (P = .078) had an increasing trend in response to SPD1. Furthermore, SPD1 increased the expression of the vascular endothelial cell marker protein, platelet endothelial cell adhesionmolecule-1 (PECAM-1/CD31) and the density of placental stromal vessels (P < .05). Moreover, as compared to CON, SPD2 significantly decreased the average number of mummified fetus per litter (P < .05), while the placental efficiency and the expression of amino acid transporter solute carrier (SLC) family 7, member7 (SLC7A7) and glucose transporters SLC2A2) and SLC5A4 in placental tissue significantly increased (P < .05). These results suggest that maternal supplementation of SPD during pregnancy increased healthy litter number, and promoted placental tissue development. Our findings provide evidence that maternal SPD has the potential to improve the production performance of sows.

Effects of altrenogest supplementation in late lactation on reproductive performance of primiparous sows

Genetic selection for hyperprolific sows resulted in higher proportion of low birthweight piglets and greater birthweight variation within the litter, increasing preweaning mortality. There is evidence that altrenogest supplementation improves post-weaning reproductive performance through higher ovulation rates, and increased embryo survival. This study aimed to evaluate the impacts of altrenogest supplementation during the last week of lactation in primiparous sows on subsequent reproductive performance. Ninety-six primiparous females were randomly assigned to two treatments: ALT-sows supplemented orally with 20 mg of altrenogest (n = 46) during the last six days of lactation up to 24 h before weaning; and CON- non-supplemented sows (n = 50). Ten sows from each experimental group were randomly selected to evaluate plasma progesterone concentrations on days 1 and 3 of treatment, at weaning and at 48, 72 and 96 h after estrus onset. Farrowings were monitored and piglets' individual birthweight, total number of piglets born, born alive, stillborn and mummified were recorded. Stillborn piglets were necropsied to assess organ weight. A subgroup of five females per treatment was euthanized on the day of estrus onset for morphological analysis of the reproductive tract. ALT females showed higher progesterone levels 72h after estrus onset (P < 0.05). Moreover, piglets' birthweight, total number of piglets born, liveborn, stillborn, and mummified were similar between experimental groups. Data collected from stillborn necropsies showed that birthweight was the main factor affecting organ weights (P < 0.05). Correlation analysis revealed that piglets weighing 600-800g presented higher brain:liver weight ratio, a determinant factor of intrauterine growth restriction, which was predominant in males (P < 0.05), and ALT females showed fewer piglets within that birthweight range (P < 0.05). Interestingly, ALT sows showed higher number, but smaller endometrial glands (P < 0.05). Taken together, short-term altrenogest supplementation in the last week of lactation increased progesterone levels after estrus onset, improving uterine vascularization and endometrial glands hyperplasia in the pre-implantation period, which benefit embryo development, leading to a decrease in the proportion of low birthweight piglets.

Maternal Ferrous Sucrose Supplementation Improves Reproductive Performance of Sows and Hepatic Iron Stores of Neonatal Piglets

As one of the most important trace elements required by sows, especially in the late gestation period, iron plays a crucial role in the growth and development of a fetus. To explore the effects of dietary supplementation with ferrous sucrose on the reproductive performance of sows and the hepatic iron stores in offspring, sixty primiparous Landrace × Yorkshire sows on day 95 of gestation with an average body weight of 174.1 ± 7.7 kg were randomly assigned to two groups of a basic diet (control) and a basic diet supplemented with 109 mg/kg ferrous sucrose (FS) in a fully randomized block design. The trial lasted for 20 days. The results showed that maternal supplementation with ferrous sucrose significantly increased litter weight (p = 0.002) in neonatal piglets. Compared with the control group, the serum iron and serum transferrin saturation of farrowing sows increased by 45.67% (p = 0.002) and 37.01% (p = 0.033), respectively, and umbilical cord serum iron (p = 0.012) also increased in the FS group. Finally, the serum iron (p < 0.001) and hepatic iron stores (p = 0.071) of neonatal piglets were both increased to varying degrees. Taken together, supplementation of pregnant sows with ferrous sucrose has positive effects on the growth and hepatic iron stores of their offspring.

The structure of the porcine uterine-conceptus interface is associated with gestational day, fetal size and sex

This study aimed to characterize histological changes of the maternal-conceptus interface in feto-placental units associated with fetal weight and sex throughout pregnancy. Pregnant Large-White X Landrace gilts(n=18) were euthanized and hysterectomized on gestational days[GDs] 30(n=3), 45(n=5), 60(n=5), and 90(n=5). Intact cross-sections of fetoplacental interface associated with the lightest[LW] and normally-grown[NW] littermates were collected on GD30(n=4 per size). On GDs 45, 60 and 90, interactions between fetal size and sex were investigated in light-weight males[LWM] and females[LWF]; normal-weight males[NWM] and females[NWF] (n=4/group/GD). Fetal weight did not affect the endometrium composition, including relative proportion of glandular epithelium, blood vessels, and connective tissue. Feto-placental units from LW embryos tended to have longer chorioallantoic fold length on GD30(P=0.06). On GD45, higher proportion of larger endometrial glands was observed in NWM, and taller trophoblastic epithelium in NW conceptuses, regardless of sex(P<0.05). NWF presented the greatest proportion of subluminal endometrial epithelial blood vessels(P<0.05). On GD60, more blood vessels were present at the folds' base in males feto-placental units, whereas taller trophoblastic epithelium were present in NWF fetuses' feto-placental units(P<0.05). Feto-placental units' morphological composition throughout gestation in NW and LW conceptuses revealed that fold length was higher as early as GD30, with no further increase up to GD90 in LW conceptuses(P>0.05). Increased proportion of glandular epithelium was observed in LW conceptuses; the highest percentage present on GD90(P<0.05). Collectively, we demonstrated that fetal weight and sex influence the morphological structure of feto-placental units from as early as GD30, suggesting potential differences in the ability for nutrient transport.

International Symposium on Ruminant Physiology: Maternal nutrient supply: Impacts on physiological and whole animal outcomes in offspring

Demands for animal products are projected to increase in the future, and animal production is key to agricultural sustainability and food security; consequently, enhancing ruminant livestock production efficiencies in sustainable ways is a major goal for the livestock industry. Developmental programming is the concept that various stressors, including compromised maternal nutrition during critical developmental windows will result in both short- and long-term changes in the offspring. Ruminant models of developmental programming indicate that compromised maternal nutrition, including global under and over-nutrition, macronutrients, and specific micronutrients, including amino acids (Met and Arg), vitamins (folate, B12, and choline), and minerals (sulfur, cobalt, and selenium) can alter offspring outcomes. Data also suggest that maternal histotrophic composition, placental function, and likely fetal nutrient supply are altered by compromised maternal nutrition. Likewise, in offspring, visceral organ mass and function, metabolism, growth, and reproduction are affected. Findings from multi-omics approaches demonstrate that compromised maternal nutrition alters transcript abundance, metabolomic profiles, and multiple metabolic pathways. The underlying mechanisms of developmental programming are driven by epigenetic events, which depend on one-carbon metabolism and micronutrient supply. Current findings indicate that developmental programming in ruminants is real, that maternal nutrition can be a major driver of developmental programming, and that genomic and metabolomic changes in offspring are modulated by altered maternal nutrition during critical windows of development. Research needs in the area of developmental programming in ruminants include: enhanced understanding of the underlying mechanisms, practical relevance to production systems, impacts on short- and long-term animal health including longevity, interrelationships between maternal and paternal influences, intergenerational impacts, and interrelationships with the host microbiome. Additionally, strategic supplementation and precision nutrition approaches should be developed to foster the positive and mitigate the negative aspects of developmental programming to improve the efficiency and sustainability of ruminant livestock production systems.

International Symposium on Ruminant Physiology: Paternal Nutrient Supply: Impacts on Physiological and Whole Animal Outcomes in Offspring

Recent evidence suggests that environmental factors experienced by sires can be transmitted through the ejaculate (seminal plasma + sperm) into the female reproductive tract, influencing fertilization, embryo development, and postnatal offspring outcomes. This concept is termed paternal programming. In rodents, sire nutrition was shown to directly alter offspring outcomes through sperm epigenetic signatures, DNA damage/oxidative stress, cytokine profiles, and/or the seminal microbiome. Response variables impacted in rodent models, including adiposity, muscle mass, metabolic responses, and reproductive performance, could have major productivity and financial implications for producers if these paternal programming responses are also present in ruminant species. However, a paucity of data exist regarding paternal programming in ruminants. The limited data in the literature mainly point to alterations in sperm epigenome as a result of sire diet or environment. Global nutrition has been implicated in ruminant models to alter seminal cytokine profiles, which could subsequently alter the uterine environment and immune response to mating. Several reports indicate that embryo development and epigenetic signatures can be impacted by sire plane of nutrition and inclusion of specific feed ingredients into diets (polyunsaturated fatty acids, folic acid, and rumen protected methionine). Models of sheep nutrition indicate that addition of rumen protected methionine can impact DNA methylation and offspring performance characteristics extending to the F3 generation, and that divergent planes of sire nutrition can cause altered hormone profiles and insulin/glucose metabolism in offspring. There are almost unlimited opportunities for discovery in this area, but researchers are encouraged to target critical questions such as whether and the extent to which paternal programming effects are present in common management scenarios, the mechanisms by which paternal programming is inherited in ruminants, and whether the effects of paternal nutrition interact with those of maternal nutrition to influence offspring physiology, whole animal outcomes, and herd or flock productivity.

Protracted maternal malnutrition induces aberrant changes in maternal uterine artery hemodynamics and the metabolic profiles of the dam and neonate

Malnutritional stress during gestation is a well-established driver of metabolic disfunction in offspring. Extended exposure to malnutrition requires metabolic plasticity as the animal shifts toward a catabolic state. In this paper we demonstrate the influence of malnutrition throughout gestation on uterine artery hemodynamics and the metabolism of the dam and neonate. We hypothesized that gestational malnutrition reduces blood flow of the maternal uterine artery and regulates the metabolic profile of the dam and offspring. Further, the combination of these factors consequently influences the concentration of metabolites in the cerebrospinal fluid of the neonate at birth. To test our hypotheses, pregnant cows caring a single female fetus were assigned to treatments by age and body condition score to one of three individually-fed dietary treatments: Underfed, Control, or Overfed throughout gestation. Uterine blood flow was measured via transrectal Doppler ultrasonography in late gestation. Blood samples were collected from dams throughout gestation, and blood and cerebrospinal fluid were collected from neonates at birth to analyze concentration of metabolites. In the current report, we reveal that maternal malnutrition regulates uterine artery hemodynamics and the maternal metabolic profile throughout gestation. This is the first report to demonstrate that maternal undernutrition leads to an increase in the concentration of urea nitrogen in neonates. Finally, a concentration gradient of metabolites from the dam to neonatal cerebrospinal fluid was observed, which may have potential implications for central nervous system development. These findings not only illustrate the complexity of the maternal-to-fetal interaction required to support the growth of the fetus and homeostasis of the dam but also reveals a novel avenue for investigating the influence of protracted maternal malnutrition on metabolic pathway preferences in offspring. Moreover, these findings are of paramount importance in the development of intervention strategies for morbid neonates.

Altered purine and pentose phosphate pathway metabolism in uteroplacental insufficiency-induced intrauterine growth restriction offspring rats impair intestinal function

This study aimed to identify metabolic alterations in the small intestine of newborn rats with intrauterine growth restriction (IUGR), a condition linked to intestinal dysfunction. Pregnant Sprague Dawley rats underwent bilateral uterine artery ligation on gestational day 17 to induce intrauterine growth restriction or sham surgery. Rat pups were delivered spontaneously on gestational day 22. Small intestine tissues were collected on postnatal days 0 and 7 from offspring. Liquid chromatography-mass spectrometry analysis was performed to investigate untargeted metabolomic profiles. Western blot analysis assessed protein expression of key regulators. Newborn rats with intrauterine growth restriction exhibited distinct small intestine metabolic profiles compared to controls on postnatal day 0. Notably, significant alterations were observed in purine metabolism, the pentose phosphate pathway, and related pathways. Western blot analysis revealed a decrease expression in transketolase, a key enzyme of the pentose phosphate pathway, suggesting impaired activity of the pentose phosphate pathway. Additionally, decreased expression of tight junction proteins ZO-1 and occludin indicated compromised intestinal barrier function in rats with intrauterine growth restriction. Similar metabolic disruptions persisted on postnatal day 7, with further reductions in tricarboxylic acid cycle intermediates and folate biosynthesis precursors. Interestingly, lysyl-glycine, a protein synthesis marker, was elevated in rats with intrauterine growth restriction. Our findings reveal a distinct metabolic signature in the small intestine of neonatal rats with intrauterine growth restriction, characterized by disruptions in the pentose phosphate pathway, purine metabolism, and energy production pathways. These novel insights suggest potential mechanisms underlying IUGR-associated intestinal dysfunction and impaired growth.

Dietary 25-Hydroxycholecalciferol Supplementation from Day 85 of Gestation to Farrowing Enhances Performance, Antioxidant Capacity, and Immunoglobulins of Sows and Newborn Piglets

In this study, the aim was to evaluate the effects of dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation on performance, antioxidant capacity, and immunoglobulin level of sows and newborn piglets. On day 85 of gestation, forty Landrace × Yorkshire gestating sows (average body weight of 241 ± 6.8 kg; average parity of 3.47 ± 0.6) were allotted into two treatments (20 replicates per treatment) based on parity, body weight, and back fat thickness. From day 85 of gestation to farrowing, sows were fed a normal vitamin D3 diet as control (containing 50 μg/kg vitamin D3; CON), or a 25-hydroxycholecalciferol-supplemented diet (containing 50 μg/kg 25-hydroxycholecalciferol). Compared with CON, dietary 25-hydroxycholecalciferol supplementation increased (p < 0.05) protein and fat content in colostrum and the average birth body weight of newborn piglets. Sows fed 25-hydroxycholecalciferol showed increased (p < 0.05) apparent total tract digestibility of crude protein compared with CON. Diets supplemented with 25-hydroxycholecalciferol also increased (p < 0.05) the content of superoxide dismutase (SOD), and tended to increase (p = 0.06) the total antioxidant capacity content and reduce (p = 0.09) the malondialdehyde (MDA) level in colostrum. An increase (p < 0.05) in the content of SOD and a reduction (p < 0.05) in the content of MDA in the serum of newborn piglets was also observed in the 25-hydroxycholecalciferol treatment compared with CON. Dietary 25-hydroxycholecalciferol supplementation also enhanced (p < 0.05) the immunoglobulin G content and reduced (p < 0.05) the concentration of tumor nuclear factor-α in the serum of sows, as well as reducing (p < 0.05) the content of immunoglobulin G and immunoglobulin A in the serum of newborn piglets compared with CON. Supplementation of 25-hydroxycholecalciferol in sow diets increased (p < 0.05) the content of alkaline phosphatase in the serum and colostrum of sows, the concentration of insulin and crosslap in serum of sows, and the serum calcium content of newborn piglets compared with CON. In conclusion, dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation could enhance performance, antioxidant capacity, and immunoglobulin in sows and newborn piglets.

Maternal chitosan oligosaccharide supplementation during late gestation and lactation optimizes placental function in sows and intestinal function in 21-day-old IUGR suckling piglets

Maternal dietary supplementation with chitosan oligosaccharide (COS) has been considered as a potential intervention to mitigate the occurrence of intrauterine growth restriction (IUGR) and improve postnatal growth. The present study investigated the effect of COS as a dietary supplement for sows during late gestation and lactation on their productivity, placental function, and the intestinal health of IUGR piglets. From day (d) 85 of late gestation to d 21 of lactation, 30 sows were randomly divided into either a control group (basal diet) or a COS group (basal diet + 100 mg kg-1 COS). At d 21 of lactation, eight normal and eight IUGR littermates from eight litters belong to control sows, as well as eight IUGR littermates from COS sows, were selected for further analysis. The results showed a significant reduction in the number of stillbirths and mummies in COS groups (p < 0.05). Maternal dietary supplementation with COS also significantly up-regulated the expression levels of GLUT1, GLUT3, and VEGFA mRNA in the placenta of IUGR piglets compared to those in control group (p < 0.05). Furthermore, there was a significant decrease in MDA content and a significant increase in GSH content in the placenta of IUGR piglets from COS sows compared to those from control group (p < 0.05). Additionally, the expression levels of MUC2 and occludin mRNA as well as claudin1 protein significantly up-regulated in the jejunum of 21-day-old IUGR piglets from COS sows group compared to those from control group (p < 0.05). Moreover, IL-10 mRNA expression level was significantly increased while MDA content was significantly reduced in the jejunum of 21-day-old IUGR piglets from COS sows group compared to those from control group (p < 0.05). The results indicated that maternal dietary COS supplementation during late gestation effectively reduced the incidence of stillbirths and mummies, potentially linked to enhanced placental function, reduced oxidative stress, and improved immune status. Furthermore, maternal dietary COS supplementation exhibited positive impact on intestinal digestive and absorptive function, intestinal barrier integrity, intestinal antioxidant capacity and immune status in 21-day-old suckling IUGR piglets.

Supplementation of l-arginine in pregnant gilts affects the protein abundance of DNMT1 in 35-day fetuses

Maternal nutrition is one of the main environmental factors regulating gene expression during fetal development through epigenetic modifications. Some nutrients, such as the amino acid l-arginine, are added to maternal diets to modulate gene expression, improve the reproductive performance of females, and enhance conceptus development. This study investigated the hypothesis that supplementation of pregnant gilts with l-arginine regulates gene expression in conceptuses through epigenetic mechanisms. For this, fetal programming phenotypic markers, the expression of key epigenetic genes, and the abundance of DNA methylation proteins (DNMT3A and DNMT1) were evaluated in 25- and 35-day conceptuses from gilts supplemented (ARG) or not (CON) with 1.0 % l-arginine during early gestation. At 25 days, there were no significant differences in phenotypic markers between CON and ARG embryos (P > 0.05). Similarly, no differences were found between CON and ARG fetuses at 35 days (P > 0.05). Maternal supplementation with l-arginine did not influence the expression of the evaluated key epigenetic genes in pig embryos or fetuses, nor DNMT3A protein abundance (P > 0.05); on the other hand, DNMT1 protein abundance was lower in ARG fetuses (P = 0.002). It is concluded that supplementation of l-arginine in pregnant gilts affects epigenetic mechanisms, such as DNA methylation, in 35-day fetuses through regulation of DNMT1 levels. Further studies using transcriptomic and proteomic analysis could reveal additional epigenetic modifications in embryos and fetuses following maternal supplementation with l-arginine.

Does Exposure to Summer Season at Different Stages of Intrauterine Development and Maternal Parity Affect Health and First-Lactation Milk Production of Female Offspring of Holstein Cows?

A suboptimal intrauterine environment during gestation may result in the programming of long-lasting structural and physiological alterations in the developing fetus, leading to health and production complications in adulthood. This observational study aimed to identify the impact of exposure to the summer season at different trimesters of gestation, dam parity, and their interaction on the postpartum disease incidence, first-lactation milk production, and herd lifespan of the offspring (F1 generation). Using a dataset collected from two commercial herds, the female offspring were categorized into three groups based on the trimester their dams experienced summer season during pregnancy: (1) first trimester (n = 2345), (2) second trimester (n = 3513), and (3) final trimester (n = 4988). The estimated 305-day milk production was lower in daughters (as a first-lactation cow) born to dams exposed to summer season during the first vs. third trimester. Summer season exposure during the first vs. third trimester resulted in the offspring that were less likely to remain in the herd (hazard ratio = 0.90; 95% CI = 0.84-0.95). Daughters of parous vs. nulliparous dams were more likely to experience dystocia and metritis but less likely to experience retained placenta. The risk of culling was higher in daughters of parous vs. nulliparous dams. Our preliminary findings suggest that the first trimester is a critical determinant of the female progeny's future productive performance and survivability. Dam parity was also identified as an influential factor affecting offspring health, as dystocia and metritis were more prevalent, and the culling risk was greater in daughters born to parous dams.

The Research Progress of DNA Methylation in the Development and Function of the Porcine Placenta

The pig is the most widely consumed domestic animal in China, providing over half of the meat supply in food markets. For livestock, a key economic trait is the reproductive performance, which is significantly influenced by placental development. The placenta, a temporary fetal organ, is crucial for establishing maternal-fetal communication and supporting fetal growth throughout pregnancy. DNA methylation is an epigenetic modification that can regulate the gene expression by recruiting proteins involved in gene silencing or preventing transcription factor binding. To enhance our understanding of the molecular mechanisms underlying DNA methylation in porcine placental development, this review summarizes the structure and function of the porcine placenta and the role of DNA methylation in placental development.

lncRNA-gene network analysis reveals the effects of early maternal nutrition on mineral homeostasis and energy metabolism in the fetal liver transcriptome of beef heifers

Maternal nutrition during pregnancy influences fetal development; however, the regulatory markers of fetal programming across different gestational phases remain underexplored in livestock models. Herein, we investigated the regulatory role of long non-coding RNAs (lncRNAs) on fetal liver gene expression, the impacts of maternal vitamin and mineral supplementation, and the rate of maternal body weight gain during the periconceptual period. To this end, crossbred Angus heifers (n=31) were randomly assigned to a 2×2 factorial design to evaluate the main effects of the rate of weight gain (low gain [LG, avg. daily gain of 0.28 kg/day] vs. moderate gain [MG, avg. daily gain of 0.79 kg/day]) and vitamins and minerals supplementation (VTM vs. NoVTM). On day 83±0.27 of gestation, fetuses were collected for morphometric measurements, and fetal liver was collected for transcriptomic and mineral analyses. The maternal diet significantly affected fetal liver development and mineral reserves. Using an RNA-Seq approach, we identified 320 unique differentially expressed genes (DEGs) across all six comparisons (FDR <0.05). Furthermore, lncRNAs were predicted through the FEELnc pipeline, revealing 99 unique differentially expressed lncRNAs (DELs). The over-represented pathways and biological processes (BPs) were associated with energy metabolism, Wnt signaling, CoA carboxylase activity, and fatty acid metabolism. The DEL-regulated BPs were associated with metal ion transport, pyrimidine metabolism, and classical energy metabolism-related glycolytic, gluconeogenic, and TCA cycle pathways. Our findings suggest that lncRNAs regulate mineral homeostasis- and energy metabolism-related gene networks in the fetal liver in response to early maternal nutrition.

Effect of Dietary Standardized Ileal Digestible Arginine to Lysine Ratio on Reproductive Performance, Plasma Biochemical Index, and Immunity of Gestating Sows

The aim of this study was to determine the optimal SID Arg: Lys ratio for maximizing the reproductive performance, immunity and biochemical parameters of sows during gestation, the colostrum composition, and the performance of their offspring. A total of 174 multiparous sows were randomly allocated to five treatment groups varying in dietary SID Arg: Lys ratios (0.91, 1.02, 1.14, 1.25 and 1.38) through modification of the levels of Arg or alanine supplementation (the total level of nitrogen was the same in all treatments). The results showed that increasing the dietary SID Arg: Lys ratio increased the number of piglets born alive (p < 0.05, linear and quadratic). The number of stillborn piglets, the birth weight variation of born alive piglets, the birth interval (p < 0.05, linear and quadratic) and the number of mummies (p < 0.05, quadratic) reduced with increasing the dietary SID Arg: Lys ratio. Broken-line regression analysis indicated that the optimal SID Arg: Lys ratio requirement for gestating sows to maximize the number of piglets born alive was 1.25. The content of non-fat solid, total solid, protein, and energy in colostrum increased linearly and quadratically (p < 0.05) with increasing dietary SID Arg: Lys ratio. Additionally, when increasing the dietary SID Arg: Lys ratio, the concentration of IgA (p < 0.05, quadratic) and IgM (p < 0.05, linear and quadratic) of plasma increased at day 90 of gestation; IgG (p < 0.05, linear and quadratic) concentration increased at day 110 of gestation of sows. The dietary SID Arg: Lys ratio had an increasing effect (p < 0.05, linear and quadratic) on plasma insulin levels at day 90 of gestation. Furthermore, there were increases in plasma concentrations of nitric oxide and ornithine at day 110 of gestation, Arg at day 90 and 110 of gestation (p < 0.05, linear and quadratic) and total protein at day 110 of gestation (p < 0.05, linear) with increasing dietary SID Arg: Lys ratio. The results of our study indicated that increases in the dietary SID Arg: Lys ratio during gestation resulted in an increase in the number of piglets born alive, a decrease in birth intervals, and an improvement in immunity and colostrum composition. The optimal SID Arg: Lys ratio for gestating sows to maximize the number of piglets born alive was 1.25.

Endoplasmic Reticulum Stress Contributes to Intestinal Injury in Intrauterine Growth Restriction Newborn Piglets

Intrauterine growth retardation (IUGR) in piglets is associated with a high rate of morbidity and mortality after birth due to gut dysfunction, and the underlying mechanisms remain poorly understood. This study selected six pairs of IUGR newborn male piglets and normal birth weight newborn piglets (Large White × Landrace) to investigate differences in intestinal structure and digestive functions, intestinal ERS and apoptosis, intestinal barrier function, and inflammatory response. The results showed that IUGR significantly reduced the jejunal villi height (p < 0.05) and the ratio of villus-height-to-crypt-depth (p = 0.05) in neonatal piglets. Additionally, the microvilli in the jejunum of IUGR neonatal piglets were shorter than those in normal-weight piglets, and swelling of the mitochondria and expansion of the endoplasmic reticulum were observed. IUGR also significantly reduced serum glucose and lactase levels (p < 0.05) while significantly increasing mRNA levels of jejunal IRE1α, EIF2α, CHOP, Bax, Caspase9, Mucin2, Claudin-1, Occludin, ZO-1, Bcl-2, IL-6, and IFN-γ (p < 0.05), as well as GRP78 protein levels in neonatal piglets (p < 0.05). These findings suggest that IUGR impairs intestinal structure and barrier function in newborn piglets by enhancing intestinal inflammatory responses, activating intestinal ERS and the signaling pathways related to the unfolded protein response, thereby inducing ERS-related apoptosis.

Morphometric traits to estimate brain and liver weight and their ratio for the diagnosis of intrauterine growth restriction in newborn piglets

Intrauterine growth restriction (IUGR) is defined as inadequate foetal growth during gestation. In response to placenta insufficiency, IUGR piglets prioritise brain development as a survival mechanism. This adaptation leads to a higher brain-to-liver weight ratio (BrW/LW) at birth. This study assessed the potential of using morphometric traits to estimate brain (BrW) and liver (LW) weights, enabling non-invasive diagnosis of IUGR in newborn piglets. At birth, body weight (BtW) of individual piglets (n = 144) was recorded. One day (± 1) after birth, BrW and LW were measured with computed tomography (n = 94) or by weighing the organs after natural death or euthanasia (n = 50). Additionally, 20 morphometric traits were captured from images of each piglet and correlated with the BrW and LW. The morphometric traits that showed a r ≥ 0.70 in linear correlation with the BrW or LW were selected. Each selected trait was combined as an independent variable with BtW to develop multiple linear regression models to predict the BrW and LW. Six models were chosen based on the highest adjusted R2 value: three for estimating BrW and three for LW. The dataset was then randomly divided into a training (75% of the data) and a testing (remaining 25%) subsets. Within the training subset, three equations to predict the BrW and three to predict the LW were extrapolated from the six selected models. The equations were then applied to the testing subset. The accuracy of the equations in predicting organ weight was assessed by calculating mean absolute and mean absolute percentage error (MAE and MAPE) between predicted and actual BrW and LW. To predict the BrW/LW, an equation including BtW and the two morphometric traits which better predicted BrW and LW was used. In the testing dataset, the equation combining ear distance and BtW better estimated the BrW. The equation performed with a MAE of 1.95 and a MAPE of 0.06 between the true and estimated weight of the brain. For the liver, the equation combining the abdominal area delimited by a square and BtW displayed the best performance, with a MAE of 9.29 and a MAPE of 0.17 between the true and estimated weight. Finally, the MAE and MAPE between the actual and estimated BrW/LW were 0.14 and 0.17, respectively. These findings suggest that specific morphometric traits can be used to estimate brain and liver weights, facilitating accurate and non-invasive identification of IUGR in newborn piglets.

Bacillus subtilis alleviates excessive apoptosis of intestinal epithelial cells in intrauterine growth restriction suckling piglets via the members of Bcl-2 and caspase families

BACKGROUND

The intestine is a barrier resisting various stress responses. Intrauterine growth restriction (IUGR) can cause damage to the intestinal barrier via destroying the balance of intestinal epithelial cells' proliferation and apoptosis. Bacillus subtilis has been reported to regulate intestinal epithelial cells' proliferation and apoptosis. Thus, the purpose of this study was to determine if B. subtilis could regulate intestinal epithelial cells' proliferation and apoptosis in intrauterine growth restriction suckling piglets.

RESULTS

Compared with the normal birth weight group, the IUGR group showed greater mean optical density values of Ki-67-positive cells in the ileal crypt (P < 0.05). IUGR resulted in higher ability of proliferation and apoptosis of intestinal epithelial cells, by upregulation of the messenger RNA (mRNA) or proteins expression of leucine rich repeat containing G protein coupled receptor 5, Caspase-3, Caspase-7, β-catenin, cyclinD1, B-cell lymphoma-2 associated agonist of cell death, and BCL2 associated X (P < 0.05), and downregulation of the mRNA or protein expression of B-cell lymphoma-2 and B-cell lymphoma-2-like 1 (P < 0.05). However, B. subtilis supplementation decreased the mRNA or proteins expression of leucine rich repeat containing G protein coupled receptor 5, SPARC related modular calcium binding 2, tumor necrosis factor receptor superfamily member 19, cyclinD1, Caspase-7, β-catenin, B-cell lymphoma-2 associated agonist of cell death, and Caspase-3 (P < 0.05), and increased the mRNA expression of B-cell lymphoma-2 (P < 0.05).

CONCLUSION

IUGR led to excessive apoptosis of intestinal epithelial cells, which induced compensatory proliferation. However, B. subtilis treatment prevented intestinal epithelial cells of IUGR suckling piglets from excessive apoptosis. © 2024 Society of Chemical Industry.

Thriving or Striving: Comparing Intra-Uterine Growth Restricted, Low Birth Weight and Normal Birth Weight Piglets within the First 24 Hours

This observational study explored the early-life challenges of intra-uterine growth restricted (IUGR), low birth body weight (LBW), and normal birth body weight (NBW) piglets. The aim was to understand the impact of birth weight and intra-uterine growth restriction phenotype on neonatal survival and behavior. Based on weight and phenotype, piglets were classified as IUGR (n = 32), LBW (n = 34), and NBW (n = 29) immediately after birth. The piglets were litter- and sex-matched. Vitality scores were assigned based on motor activity and breathing and complemented with an assessment of umbilical cord condition, rectal temperature, crown-rump length (CRL), time to reach the udder, time to suckle, colostrum intake, and weight gain over 24 h. Beyond the lower birth weight, reduced CRL, and higher mortality rate, IUGR piglets faced several other challenges compared with LBW and NBW piglets. Growth-impaired piglets often struggled to engage in early feeding behaviors and displayed consistently lower rectal temperatures at 1, 3 and 24 h after birth. IUGR piglets showed inadequate colostrum intake and weight loss, which were also observed for LBW counterparts. In contrast, no significant differences were observed in vitality scores and umbilical cord conditions across the groups. In conclusion, our findings underscore the impact of intra-uterine growth restriction on neonatal piglets, emphasizing the need for specialized care strategies to improve survival and health outcomes in IUGR.

The Effects of Maternal Nutrient Restriction during Mid to Late Gestation with Realimentation on Fetal Metabolic Profiles in the Liver, Skeletal Muscle, and Blood in Sheep

Poor maternal nutrition during gestation negatively affects offspring growth and metabolism. To evaluate the impact of maternal nutrient restriction and realimentation on metabolism in the fetal liver, skeletal muscle, and circulation, on day 50 of gestation, ewes (n = 48) pregnant with singletons were fed 100% (CON) or 60% (RES) of requirements until day 90 of gestation, when a subset of ewes (n = 7/treatment) were euthanized, and fetal samples were collected. The remaining ewes were maintained on a current diet (CON-CON, n = 6; RES-RES, n = 7) or switched to an alternative diet (CON-RES, RES-CON; n = 7/treatment). On day 130 of gestation, the remaining ewes were euthanized, and fetal samples were collected. Fetal liver, longissimus dorsi (LD), and blood metabolites were analyzed using LC-MS/MS, and pathway enrichment analysis was conducted using MetaboAnalyst. Then, 600, 518, and 524 metabolites were identified in the liver, LD, and blood, respectively, including 345 metabolites that were present in all three. Nutrient restriction was associated with changes in amino acid, carbohydrate, lipid, and transulfuration/methionine metabolic pathways, some of which were alleviated by realimentation. Fetal age also affected metabolite abundance. The differential abundance of metabolites involved in amino acid, methionine, betaine, and bile acid metabolism could impact fetal epigenetic regulation, protein synthesis, lipid metabolism, and signaling associated with glucose and lipid metabolism.

Impact of compensatory growth on survival in newborn kittens

In the feline species, the mortality of live-born kittens over the first 2 months of life is around 10%. Although some losses are inevitable, progress in veterinary medicine and improved knowledge of feline neonatalogy should make it possible to reduce them to a lower level. The objectives of this study were: (i) to describe early growth in kittens, and (ii) to assess whether low birth weight kittens develop compensatory growth during the first week of life and if so, whether compensatory growth is associated with increased chances of survival. Using data collected from 5,504 kittens born in 193 different French catteries, five growth rates were calculated to reflect the growth of kittens during the first week after birth. Low birth weight kittens had higher growth rates than normal birth weight kittens. In addition, low birth weight kittens whose early growth was in the lowest 25% had a significantly higher 0-2 months mortality rate than all the other groups. Weight loss (or lack of weight gain) between birth and Day 2 was identified as a risk factor for 0-2 months mortality whatever the birth weight category. Finally, critical early growth thresholds were determined separately for low and normal birth weight kittens. These figures could help caregivers to validate the adequacy or inadequacy of kitten early growth. They will be able to quickly identify and provide appropriate care for the kittens whose growth is deemed insufficient in order to improve their chances of survival.

Maternal Hypermethylated Genes Contribute to Intrauterine Growth Retardation of Piglets in Rongchang Pigs

The placenta is a crucial determinant of fetal survival, growth, and development. Deficiency in placental development directly causes intrauterine growth retardation (IUGR). IUGR can lead to fetal growth restriction and an increase in the mortality rate. The genetic mechanisms underlying IUGR development, however, remain unclear. In the present study, we integrated whole-genome DNA methylation and transcriptomic analyses to determine distinct gene expression patterns in various placental tissues to identify pivotal genes that are implicated with IUGR development. By performing RNA-sequencing analysis, 1487 differentially expressed genes (DEGs), with 737 upregulated and 750 downregulated genes, were identified in IUGR pigs (H_IUGR) compared with that in normal birth weight pigs (N_IUGR) (p < 0.05); furthermore, 77 miRNAs, 1331 lncRNAs, and 61 circRNAs were differentially expressed. The protein-protein interaction network analysis revealed that among these DEGs, the genes GNGT1, ANXA1, and CDC20 related to cellular developmental processes and blood vessel development were the key genes associated with the development of IUGR. A total of 495,870 differentially methylated regions were identified between the N_IUGR and H_IUGR groups, which included 25,053 differentially methylated genes (DMEs); moreover, the overall methylation level was higher in the H_IUGR group than in the N_IUGR group. Combined analysis showed an inverse correlation between methylation levels and gene expression. A total of 1375 genes involved in developmental processes, tissue development, and immune system regulation exhibited methylation differences in gene expression levels in the promoter regions and gene ontology regions. Five genes, namely, ANXA1, ADM, NRP2, SHH, and SMAD1, with high methylation levels were identified as potential contributors to IUGR development. These findings provide valuable insights that DNA methylation plays a crucial role in the epigenetic regulation of gene expression and mammalian development and that DNA-hypermethylated genes contribute to IUGR development in Rongchang pigs.

The curse of the firstborn: Effects of dam primiparity on developmental programming in ruminant offspring

The first parity, or first pregnancy, of ruminant females has negative effects on offspring during fetal, perinatal, and pre-weaning periods which ultimately lead to diminished pre-weaning productivity. Offspring born to primiparous ruminant females can have decreased fetal and pre-weaning growth, resulting in lower body weights at birth and weaning in cattle, sheep, and goats. Moreover, mortality is greater during both neonatal and pre-weaning periods. Insults during these critical developmental windows likely also have long-term consequences on first-parity offspring through developmental programming, but less research has been done to investigate effects in the post-weaning period. Many potential physiological, metabolic, and behavioral mechanisms exist for the outcomes of dam primiparity. Although competition for nutrient partitioning between maternal and fetal growth or lactation is often cited as a major contributor, we hypothesize that the most important mechanism causing most first-parity outcomes is the relative physiological inexperience of reproductive tissues such as the uterus and mammary gland during the first pregnancy and lactation, or a "first use theory" of tissues. More research is necessary to explore these areas, as well as if primiparous dams respond differently to stressors than multiparous dams, and if stress during the first parity affects subsequent parities.

Foetal programming in sheep: Reproductive and productive implications

The aim of this study was to evaluate the effects of pregnant ewe nutrition on the performance of offspring in terms of meat, wool production, and reproduction. Foetal programming in sheep has focused on several aspects related to foetal growth, postnatal production, behaviour, and immunological performance. Currently, significant efforts are being made to understand the endocrine, metabolic, and epigenetic mechanisms involved in offspring development. Current studies have not only evaluated the foetal period, despite the pre-conception parental nutrition has demonstrated an effect on the foetal, embryonic, and pre-implantation periods and can generate permanent effects in the foetal and postnatal phases. The performance of offspring is the result of interactions between the genome, epigenome, and environmental interventions during conception. Several factors influence the expression of phenotypic characteristics in progenies; however, this study focused on presenting data on the effect of pregnant ewe nutrition alone on foetal growth and the productive aspects of their offspring.

Effects of Low and High Maternal Protein Intake on Fetal Skeletal Muscle miRNAome in Sheep

Prenatal maternal feeding plays an important role in fetal development and has the potential to induce long-lasting epigenetic modifications. MicroRNAs (miRNAs) are non-coding, single-stranded RNAs that serve as one epigenetic mechanism. Though miRNAs have crucial roles in fetal programming, growth, and development, there is limited data regarding the maternal diet and miRNA expression in sheep. Therefore, we analyzed high and low maternal dietary protein for miRNA expression in fetal longissimus dorsi. Pregnant ewes were fed an isoenergetic high-protein (HP, 160-270 g/day), low-protein (LP, 73-112 g/day), or standard-protein diet (SP, 119-198 g/day) during pregnancy. miRNA expression profiles were evaluated using the Affymetrix GeneChip miRNA 4.0 Array. Twelve up-regulated, differentially expressed miRNAs (DE miRNAs) were identified which are targeting 65 genes. The oar-3957-5p miRNA was highly up-regulated in the LP and SP compared to the HP. Previous transcriptome analysis identified that integrin and non-receptor protein tyrosine phosphatase genes targeted by miRNAs were detected in the current experiment. A total of 28 GO terms and 10 pathway-based gene sets were significantly (padj < 0.05) enriched in the target genes. Most genes targeted by the identified miRNAs are involved in immune and muscle disease pathways. Our study demonstrated that dietary protein intake during pregnancy affected fetal skeletal muscle epigenetics via miRNA expression.

Uteroplacental insufficiency decreases leptin expression and impairs lung development in growth-restricted newborn rats

BACKGROUND

The study aimed to analyze the effect of uteroplacental insufficiency (UPI) on leptin expression and lung development of intrauterine growth restriction (IUGR) rats.

METHODS

On day 17 of pregnancy, time-dated Sprague-Dawley rats were randomly divided into either an IUGR group or a control group. Uteroplacental insufficiency surgery (IUGR) and sham surgery (control) were conducted. Offspring rats were spontaneously delivered on day 22 of pregnancy. On postnatal days 0 and 7, rats' pups were selected at random from the control and IUGR groups. Blood was withdrawn from the heart to determine leptin levels. The right lung was obtained for leptin and leptin receptor levels, immunohistochemistry, proliferating cell nuclear antigen (PCNA), western blot, and metabolomic analyses.

RESULTS

UPI-induced IUGR decreased leptin expression and impaired lung development, causing decreased surface area and volume in offspring. This results in lower body weight, decreased serum leptin levels, lung leptin and leptin receptor levels, alveolar space, PCNA, and increased alveolar wall volume fraction in IUGR offspring rats. The IUGR group found significant relationships between serum leptin, radial alveolar count, von Willebrand Factor, and metabolites.

CONCLUSION

Leptin may contribute to UPI-induced lung development during the postnatal period, suggesting supplementation as a potential treatment.

IMPACT

The neonatal rats with intrauterine growth restriction (IUGR) caused by uteroplacental insufficiency (UPI) showed decreased leptin expression and impaired lung development. UPI-induced IUGR significantly decreased surface area and volume in lung offspring. This is a novel study that investigates leptin expression and lung development in neonatal rats with IUGR caused by UPI. If our findings translate to IUGR infants, leptin may contribute to UPI-induced lung development during the postnatal period, suggesting supplementation as a potential treatment.

Increasing the Understanding of Nutrient Transport Capacity of the Ovine Placentome

Placental nutrient transport capacity influences fetal growth and development; however, it is affected by environmental factors, which are poorly understood. The objective of this study was to understand the impact of the ovine placentome morphological subtype, tissue type, and maternal parenteral supplementation of arginine mono-hydrochloride (Arg) on nutrient transport capacity using a gene expression approach. Placentomal tissues of types A, B, and C morphologic placentome subtypes were derived from 20 twin-bearing ewes, which were infused thrice daily with Arg (n = 9) or saline (Ctrl, n = 11) from 100 to 140 days of gestation. Samples were collected at day 140 of gestation. Expression of 31 genes involved in placental nutrient transport and function was investigated. Differential expression of specific amino acid transporter genes was found in the subtypes, suggesting a potential adaptive response to increase the transport capacity. Placentomal tissues differed in gene expression, highlighting differential transport capacity. Supplementation with Arg was associated with differential expressions of genes involved in amino acid transport and angiogenesis, suggesting a greater nutrient transport capacity. Collectively, these results indicate that the morphological subtype, tissue type, and maternal Arg supplementation can influence placental gene expression, which may be an adaptive response to alter the transport capacity to support fetal growth in sheep.

Effects of foetal size, sex and developmental stage on adaptive transcriptional responses of skeletal muscle to intrauterine growth restriction in pigs

Intrauterine growth restriction (IUGR) occurs both in humans and domestic species. It has a particularly high incidence in pigs, and is a leading cause of neonatal morbidity and mortality as well as impaired postnatal growth. A key feature of IUGR is impaired muscle development, resulting in decreased meat quality. Understanding the developmental origins of IUGR, particularly at the molecular level, is important for developing effective strategies to mitigate its economic impact on the pig industry and animal welfare. The aim of this study was to characterise transcriptional profiles in the muscle of growth restricted pig foetuses at different gestational days (GD; gestational length ~ 115 days), focusing on selected genes (related to development, tissue injury and metabolism) that were previously identified as dysregulated in muscle of GD90 fetuses. Muscle samples were collected from the lightest foetus (L) and the sex-matched foetus with weight closest to the litter average (AW) from each of 22 Landrace x Large White litters corresponding to GD45 (n = 6), GD60 (n = 8) or GD90 (n = 8), followed by analyses, using RT-PCR and protein immunohistochemistry, of selected gene targets. Expression of the developmental genes, MYOD, RET and ACTN3 were markedly lower, whereas MSTN expression was higher, in the muscle of L relative to AW littermates beginning on GD45. Levels of all tissue injury-associated transcripts analysed (F5, PLG, KNG1, SELL, CCL16) were increased in L muscle on GD60 and, most prominently, on GD90. Among genes involved in metabolic regulation, KLB was expressed at higher levels in L than AW littermates beginning on GD60, whereas both IGFBP1 and AHSG were higher in L littermates on GD90 but only in males. Furthermore, the expression of genes specifically involved in lipid, hexose sugar or iron metabolism increased or, in the case of UCP3, decreased in L littermates on GD60 (UCP3, APOB, ALDOB) or GD90 (PNPLA3, TF), albeit in the case of ALDOB this only involved females. In conclusion, marked dysregulation of genes with critical roles in development in L foetuses can be observed from GD45, whereas for a majority of transcripts associated with tissue injury and metabolism differences between L and AW foetuses were apparent by GD60 or only at GD90, thus identifying different developmental windows for different types of adaptive responses to IUGR in the muscle of porcine foetuses.

Insulin resistance and dyslipidemia in low-birth-weight goat kids

Low birth weight (LBW) impairs the development and health of livestock by affecting postnatal growth performance and metabolic health in adulthood. Previous studies on indigenous goats in southwest China showed that LBW goat kids had higher mortality and morbidity rates, including hepatic dyslipidemia and liver damage. However, the mechanism of insulin resistance affecting lipid metabolism under LBW conditions remains unclear. In this study, we conducted in vivo glucose-insulin metabolic studies, measured biochemical parameters, and analyzed related regulatory pathways. Both glucose tolerance tests and insulin tolerance tests indicated insulin resistance in LBW goat kids compared to controls (p < 0.05). The marker of insulin resistance, homeostasis model assessment (HOMA), was 2.85-fold higher in LBW than in control goats (p < 0.01). Additionally, elevated levels of free fatty acids in both plasma and skeletal muscle were observed in LBW goats compared to normal birth weight (NBW) goats (p < 0.05). Transcriptome analysis revealed impairments in lipid metabolism and insulin signaling in LBW goats. The observed lipid accumulation was associated with the upregulation of genes linked to fatty acid uptake and transport (FABP3), fatty acid oxidation (PPARA), triacylglycerol synthesis (LPIN1 and DGAT1), oxidative stress (ANKRD2), and insulin resistance (PGC1α). Furthermore, the insulin receptor substrate 2 (IRS2) was lower in the liver of LBW goat kids (p < 0.05). While there was no change in insulin function in skeletal muscle, LBW may lead to lipid accumulation in skeletal muscle by interfering with insulin function in the liver. These findings collectively impact the health and growth performance of livestock.

Longitudinal intravital imaging of mouse placenta

Studying placental functions is crucial for understanding pregnancy complications. However, imaging placenta is challenging due to its depth, volume, and motion distortions. In this study, we have developed an implantable placenta window in mice that enables high-resolution photoacoustic and fluorescence imaging of placental development throughout the pregnancy. The placenta window exhibits excellent transparency for light and sound. By combining the placenta window with ultrafast functional photoacoustic microscopy, we were able to investigate the placental development during the entire mouse pregnancy, providing unprecedented spatiotemporal details. Consequently, we examined the acute responses of the placenta to alcohol consumption and cardiac arrest, as well as chronic abnormalities in an inflammation model. We have also observed viral gene delivery at the single-cell level and chemical diffusion through the placenta by using fluorescence imaging. Our results demonstrate that intravital imaging through the placenta window can be a powerful tool for studying placenta functions and understanding the placental origins of adverse pregnancy outcomes.

The importance of developmental programming in the dairy industry

The concept of developmental programming suggests that environmental influences during pre- and early postnatal life that can have long-term effects on future health and performance. In dairy cattle, maternal body growth, age, parity and milk yield, as well as environmental factors during gestation, have the potential to create a suboptimal environment for the developing fetus. As a result, the calf's phenotype may undergo adaptations. Moreover, developmental programming can have long-term effects on subsequent birth weight, immunity and metabolism, as well as on postnatal growth, body composition, fertility, milk yield and even longevity of dairy cows. This review provides an overview of the impact of developmental programming on later health and performance in dairy cows.

The Effect of Birth Weight on Fattening Performance, Meat Quality, and Muscle Fibre Characteristics in Lambs of the Karayaka Native Breed

This investigation aimed to assess the influence of birth weight on post-weaning fattening performance, meat quality, muscle fibre characteristics, and carcass traits in Karayaka lambs. The study categorized the lambs into three distinct groups based on birth weight: low birth weight (LBW), medium birth weight (MBW), and high birth weight (HBW). Throughout the fattening phase, the lambs were given ad libitum access to food and water, culminating in the slaughter at the end of the study. Following slaughter, warm and cold carcasses were weighted, and specific muscles (longissimus thoracis et lumborum [LTL], semitendinosus [ST], and semimembranosus [SM]) were isolated for the evaluation of muscle weights, muscle fibre types (Type I, Type IIA, and Type IIB), and muscle fibre numbers. Carcass characteristics were also determined, including eye muscle (LTL) fat, loin thickness, and meat quality characteristics, such as pH, colour, texture, cooking loss, and water-holding capacity. The statistical analysis revealed highly significant differences among the experimental groups concerning muscle weights and warm and cold carcass weights (p < 0.01), with the lambs in the HBW group exhibiting a notably higher carcass yield (in females: 45.65 ± 1.34% and in males: 46.18 ± 0.77%) and LTL, ST, and SM (except for female lambs) muscle weights than the lambs in LBW group (p < 0.01). However, apart from the texture of LTL and ST muscles, no significant differences in meat quality parameters were observed among the treatment groups (p > 0.05). Notably, the birth weight of lambs did not impart a discernible effect on the total number and metabolic activity of muscle fibres in LTL, ST, and SM muscles. Nonetheless, a noteworthy distinction in the fibre area of Type I fibres in the LTL muscle of male lambs (LBW: 30.4 ± 8.9, MBW: 29.1 ± 7.3 and HBW; 77.3 ± 15.4) and in the ST muscle of female lambs (LBW: 44.1 ± 8.1, MBW: 38.8 ± 7.7 and HBW: 36.9 ± 7.1) were evident among the birth weight groups (p < 0.05). The study also found that the mean fat thickness values of eye muscles in Karayaka lambs, as obtained by ultrasonic tests, were below the typical range for sheep. In synthesis, the outcomes of this study underscore the considerable impact of birth weight on slaughtered and carcass weights, emphasizing the positive association between higher birth weights and enhanced carcass yield. Remarkably, despite these pronounced effects on carcass traits, the birth weight did not demonstrate a statistically significant influence on meat quality or overall muscle fibre characteristics, except for the area of Type I fibres in the LTL muscle. This nuanced understanding contributes valuable insights into the intricate relationship between birth weight and various physiological and carcass parameters in Karayaka lambs undergoing post-weaning fattening.

Evaluation of Muscle Long Non-Coding RNA Profile during Rearing and Finishing Phase of Bulls Subjected to Different Prenatal Nutritional Strategies

Maternal nutrition has the ability of influence critical processes in fetal life, including muscle development. Also, in this period, epigenetic sensitivity to external stimuli is higher and produces long-lasting effects. Thus, the aim of this study was to investigate epigenetic mechanisms, including the identification and characterization of long non-coding RNA (lncRNA) from animals that had undergone different strategies of prenatal supplementation. A group of Nellore cows (n = 126) were separated into three nutritional plans: NP (control)-Not Programmed, without protein-energy supplementation; PP-Partially Programmed, protein-energy supplementation in the final third of pregnancy; and CP-Complete Programming, protein-energy supplementation during the full period of gestation. A total of 63 male offspring were used in this study, of which 15 (5 per treatment) had Longissimus thoracis muscle at 15 (biopsy) and 22 months (slaughter). Biopsy samples were subjected to RNA extraction and sequencing. Differential expression (DE) of remodeling factors and chromatin-modifying enzyme genes were performed. For the identification and characterization of lncRNA, a series of size filters and protein coding potential tests were performed. The lncRNAs identified had their differential expression and regulatory potential tested. Regarding DE of epigenetic mechanisms, no differentially expressed gene was found (p > 0.1). Identification of potential lncRNA was successful, identifying 1823 transcripts at 15 months and 1533 at 22 months. Among these, four were considered differentially expressed between treatments at 15 months and 6 were differentially expressed at 22 months. Yet, when testing regulatory potential, 13 lncRNAs were considered key regulators in the PP group, and 17 in the CP group. PP group lncRNAs possibly regulate fat-cell differentiation, in utero embryonic development, and transforming growth factor beta receptor, whereas lncRNA in the CP group regulates in utero embryonic development, fat-cell differentiation and vasculogenesis. Maternal nutrition had no effect on differential expression of epigenetic mechanisms; however, it seems to impair lncRNA regulation of epigenetics.

Lactobacillus amylovorus Promotes Lactose Utilization in Small Intestine and Enhances Intestinal Barrier Function in Intrauterine Growth Restricted Piglets

BACKGROUND

Intrauterine growth restriction (IUGR) resulted in high mortality and many physiological defects of piglets, causing huge economic loss in the swine industry. Lactobacillus amylovorus (L. amylovorus) was identified as one of the main differential bacteria between IUGR and normal piglets. However, the effects of L. amylovorus on the growth performance and intestinal health in IUGR piglets remained unclear.

OBJECTIVES

This study aimed to investigate the promoting effects of L. amylovorus Mafic1501, a new strain isolated from normal piglets, on the growth performance and intestinal barrier functions in IUGR piglets.

METHODS

Newborn mice or piglets were assigned into 3 groups: CON (normal birth weight, control), IUGR (low birth weight), and IUGR+L. amy (low birth weight), administered with sterile saline or L. amylovorus Mafic1501, respectively. Growth performance, lactose content in the digesta, intestinal lactose transporter, and barrier function parameters were profiled. IPEC-J2 cells were cultured to verify the effects of L. amylovorus Mafic1501 on lactose utilization and intestinal barrier functions.

RESULTS

L. amylovorus Mafic1501 elevated body weight and average daily gain of IUGR mice and piglets (P < 0.05). The lactose content in the ileum was decreased, whereas gene expression of glucose transporter 2 (GLUT2) was increased by L. amylovorus Mafic1501 in IUGR piglets during suckling period (P < 0.05). Besides, L. amylovorus Mafic1501 promoted intestinal barrier functions by increasing the villus height and relative gene expressions of tight junctions (P < 0.05). L. amylovorus Mafic1501 and its culture supernatant decreased the lactose level in the medium and upregulated gene expressions of transporter GLUT2 and tight junction protein Claudin-1 of IPEC-J2 cells (P < 0.05).

CONCLUSION

L. amylovorus Mafic1501 improved the growth performance of IUGR piglets by promoting the lactose utilization in small intestine and enhancing intestinal barrier functions. Our results provided the new evidence of L. amylovorus Mafic1501 for its application in the swine industry.

Nutrient restriction during late gestation reduces milk yield and mammary blood flow in lactating primiparous beef females

Fall-calving primiparous beef females [body weight (BW): 451 ± 28 (SD) kg; body condition score (BCS): 5.4 ± 0.7] were individually-fed 100% (control; CON; n = 13) or 70% (nutrient restricted; NR; n = 13) of estimated metabolizable energy and metabolizable protein requirements from day 160 of gestation to calving. Post-calving, all dams were individually-fed tall fescue hay supplemented to meet estimated nutrient requirements for maintenance, growth, and lactation until day 149 of lactation. Four-hour milk yields were collected on days 21, 42, 63, 84, 105, and 147 of lactation, and milk nutrient composition was determined. Doppler ultrasonography of both pudendoepigastric arterial trunks was conducted every 21 d from days 24 to 108 of lactation. Total mammary blood flow was calculated, and hemodynamics from both sides were averaged. Data were analyzed as repeated measures with nutritional plane, day of lactation, their interaction, calving date, and calf sex (if P < 0.25) as fixed effects. We previously reported that post-calving, NR dams weighed 64 kg less and were 2.0 BCS lower than CON, but calf birth weight was not affected. Milk weight and volume were 15% less (P = 0.04) for NR dams than CON. Milk protein concentration was lower (P = 0.008) for NR dams than CON, but triglyceride and lactose concentrations were not affected (P ≥ 0.20) by nutritional plane. Milk urea N concentration of NR dams tended to be greater (P = 0.07) on day 42 but was lower (P = 0.01) on day 147 of lactation than CON. Total milk protein, triglyceride, and lactose yields were less (P ≤ 0.05) for NR dams than CON. Total milk urea N yield was less (P ≤ 0.03) for NR dams than CON on days 21, 63, and 147 of lactation. Maternal heart rate was greater (P = 0.008), but pudendoepigastric arterial trunk peak systolic velocity, resistance index, and cross-sectional area were less (P ≤ 0.04) and pulsatility index tended to be less (P = 0.06) for NR dams than CON. Mammary blood flow was 19% less (P = 0.004) for NR dams than CON, but mammary blood flow relative to milk weight or dam BW was not affected (P ≥ 0.14) by nutritional plane. Most milk yield, milk nutrient composition, and mammary blood flow variables were affected (P ≤ 0.04) by day of lactation. In summary, first-parity beef females that were nutrient restricted during late gestation and then fed to meet estimated nutrient requirements during lactation had decreased milk nutrient yield and a similar reduction in mammary blood flow.

Dietary glycine supplementation enhances creatine availability in tissues of pigs with intrauterine growth restriction

This study tested the hypothesis that dietary supplementation with glycine (Gly) enhances the synthesis and availability of creatine (Cr) in tissues of pigs with intrauterine growth restriction (IUGR). At weaning (21 d of age), IUGR pigs and litter mates with normal birth weights (NBW) were assigned randomly to 1 of the 2 groups, namely, supplementation with 1% Gly or 1.19% l-alanine (isonitrogenous control) to a corn- and soybean meal-based diet. Blood, kidneys, liver, pancreas, jejunum, longissimus lumborum muscle (LLM), and gastrocnemius muscle (GM) were obtained from the pigs within 1 wk after the feeding trial ended at 188 d of age to determine concentrations of guanidinoacetate (GAA), Cr, creatinine, and phosphocreatine (CrP). The organs were also analyzed for activities and mRNA levels for Cr-synthetic enzymes: l-arginine:glycine amidinotransferase (AGAT; forming GAA from Gly and l-arginine) and guanidinoacetate n-methyltransferase (GAMT; converting GAA and l-methionine into Cr). AGAT activity was present in the kidneys, liver, and pancreas, whereas GAMT activity was found in all the organs analyzed. AGAT and GAMT were most active per gram of tissue in the kidneys and pancreas, respectively. Based on tissue mass, the kidneys had the greatest (P < 0.001) AGAT activity per whole organ, followed by the liver, while skeletal muscle had the greatest (P < 0.001) GAMT activity per whole organ, followed by the liver. Thus, the kidneys played a dominant role in forming GAA, whereas skeletal muscle and liver were the major sites for converting GAA into Cr. Dietary supplementation with 1% Gly enhanced AGAT activity in the kidneys and pancreas but reduced GAMT activity in the pancreas and small intestine, therefore directing GAA to the liver and skeletal muscle for Cr production. IUGR selectively reduced the concentration of Cr in LLM among all the organs studied. Except for the GM that had greater mRNA levels for GAMT in IUGR than in NBW pigs, neither Gly nor IUGR affected mRNA levels for the selected genes in the tissues examined. Collectively, these novel results indicate that dietary Gly intake upregulates the Cr-synthetic pathway in swine.

Dietary glycine supplementation enhances glutathione availability in tissues of pigs with intrauterine growth restriction

This study tested the hypothesis that dietary supplementation with glycine enhances the synthesis and concentrations of glutathione (GSH, a major antioxidant) in tissues of pigs with intrauterine growth restriction (IUGR). At weaning (21 d of age), IUGR pigs and litter mates with normal birth weights (NBW) were assigned randomly to one of two groups, representing supplementation with 1% glycine or 1.19% l-alanine (isonitrogenous control) to a corn- and soybean meal-based diet. Blood and other tissues were obtained from the pigs within 1 wk after the feeding trial ended at 188 d of age to determine GSH, oxidized GSH (GSSG), and activities of GSH-metabolic enzymes. Results indicated that concentrations of GSH + GSSG or GSH in plasma, liver, and jejunum (P < 0.001) and concentrations of GSH in longissimus lumborum and gastrocnemius muscles (P < 0.05) were lower in IUGR pigs than in NBW pigs. In contrast, IUGR increased GSSG/GSH ratios (an indicator of oxidative stress) in plasma (P < 0.001), jejunum (P < 0.001), both muscles (P < 0.05), and pancreas (P = 0.001), while decreasing activities of γ-glutamylcysteine synthetase and GSH synthetase in liver (P < 0.001) and jejunum (P < 0.01); and GSH reductase in jejunum (P < 0.01), longissimus lumborum muscle (P < 0.01), gastrocnemius muscle (P < 0.05), and pancreas (P < 0.01). In addition, IUGR pigs had greater (P < 0.001) concentrations of thiobarbituric acid reactive substances (TBARS; an indicator of lipid peroxidation) in plasma, jejunum, muscles, and pancreas than NBW pigs. Compared with isonitrogenous controls, dietary glycine supplementation increased concentrations of GSH plus GSSG and GSH in plasma (P < 0.01), liver (P < 0.001), jejunum (P < 0.001), longissimus lumborum muscle (P = 0.001), and gastrocnemius muscle (P < 0.05); activities of GSH-synthetic enzymes in liver (P < 0.01) and jejunum (P < 0.05), while reducing GSSG/GSH ratios in plasma (P < 0.001), jejunum (P < 0.001), longissimus lumborum muscle (P < 0.001), gastrocnemius muscle (P = 0.01), pancreas (P < 0.05), and kidneys (P < 0.01). Concentrations of GSH plus GSSG, GSH, and GSSG/GSH ratios in kidneys were not affected (P > 0.05) by IUGR. Furthermore, glycine supplementation reduced (P < 0.001) TBARS concentrations in plasma, jejunum, muscles, and pancreas. Collectively, IUGR reduced GSH availability and induced oxidative stress in pig tissues, and these abnormalities were prevented by dietary glycine supplementation in a tissue-specific manner.

Supplementing vitamins and minerals to beef heifers during gestation: impacts on mineral status in the dam and offspring, and growth and physiological responses of female offspring from birth to puberty

We evaluated the effects of feeding a vitamin and mineral supplement to nulliparous beef heifers throughout gestation on the mineral status of the dam, calf, placenta, and colostrum; offspring growth performance; and physiological responses of offspring raised as replacement heifers. Angus-based heifers (n = 31, initial body weight [BW] = 412.5 ± 53.68 kg) were adapted to an individual feeding system for 14 d, estrus synchronized and bred with female-sexed semen. Heifers were ranked by BW and randomly assigned to receive either a basal diet (CON; n = 14) or the basal diet plus 113 g heifer-1 d-1 of the vitamin and mineral supplement (VTM; n = 17). Targeted BW gains for both treatments was 0.45 kg heifer-1 d-1. Liver biopsies were obtained from dams at breeding, days 84 and 180 of gestation. At calving, liver biopsies were taken from dams and calves; colostrum, placenta, and blood samples were collected; and calf body measurements were recorded. After calving, all cow-calf pairs received a common diet through weaning, and F1 heifer calves were managed similarly after weaning. Offspring growth performance, feeding behavior, blood metabolites, and hormones were evaluated from birth through 15 mo of age. Data were analyzed using the MIXED procedure in SAS with repeated measures where appropriate. Hepatic concentrations of Se decreased in VTM dams (P ≤ 0.05) from day 84 to calving, while concentrations of Cu decreased in VTM and CON (P ≤ 0.05) from day 84 to calving. Calf liver concentrations of Se, Cu, Zn, and Co at birth were greater for VTM than CON (P ≤ 0.05), but calf birth BW and body measurements were not different (P = 0.45). Placental Se, colostrum quantity, total Se, Cu, Zn, and Mn in colostrum were greater (P ≤ 0.04) in VTM dams than CON. Finally, offspring from VTM dams were heavier than CON (P < 0.0001) from weaning through 15 mo of age. These results were coupled with greater (P ≤ 0.04) blood glucose at birth, decreased (P ≤ 0.05) blood urea nitrogen at pasture turn out and weaning, and altered feeding behaviors in VTM offspring compared with CON. Maternal gestational vitamin and mineral supplementation enhanced mineral status in dams and F1 progeny, augmented postnatal offspring growth and blood metabolites. Consequently, in utero vitamin and mineral supplementation may exert programming outcomes on the performance and productivity of females raised as herd replacements and should be considered when developing diets for gestating cows and heifers.

Vitamin and mineral supplementation to beef heifers during gestation: impacts on morphometric measurements of the neonatal calf, vitamin and trace mineral status, blood metabolite and endocrine profiles, and calf organ characteristics at 30 h after birth

To examine the effects of feeding a vitamin and mineral supplement to beef heifers throughout gestation on mineral status and hormone/endocrine profiles in the dam and calf, and morphometric characteristics and organ mass of the calf at 30 h after birth, Angus-based heifers (n = 72, 14 to 15 mo of age, initial body weight [BW] = 380.4 ± 50.56 kg) were estrus synchronized and artificially inseminated (AI) with female-sexed semen. Heifers were blocked by BW and randomly assigned to receive either a basal diet (CON; n = 36) or a basal diet plus a vitamin and mineral supplement (VTM; n = 36) via an individual feeding system beginning at breeding, with both diets targeting BW gains of 0.45 kg heifer-1·d-1. Heifers not pregnant after the first AI (CON, n = 19; VTM, n = 18) were rebred via AI 60 d after treatment initiation, and heifers gestating female fetuses (CON, n = 7; VTM, n = 7) received treatments throughout gestation and were experimental units for this study. Calves were separated from their dams and fed colostrum replacer within 2 h of birth and euthanized 30 h after the first feeding. Calf morphometrics were recorded, and tissues were weighed and sampled. Serum from the dam at calving and serum, liver, and muscle from the calf at 30 h were analyzed for concentrations of minerals. Serum from the dam and calf were analyzed for concentrations of leptin, vitamins A, D, and E, cortisol, growth hormone, and insulin-like growth factor 1. All response variables were analyzed using the MIXED procedure of SAS. Calf body morphometrics and BW of the dam at calving (P ≥ 0.32), calf organ weights (P ≥ 0.21), and calf ovarian follicle counts (P ≥ 0.13) were not affected by maternal treatment. Concentrations of Se and Co in calf serum and Se in calf liver were increased (P ≤ 0.02) in VTM. Serum concentrations of Co and vitamin A in the dam were greater (P ≤ 0.01) in supplemented compared with nonsupplemented dams, and serum concentrations of vitamin D were greater (P ≤ 0.0003) in supplemented dams and calves compared with the nonsupplemented cohort. Maternal supplementation supported vitamin and mineral status in the neonate, yet had no discernable impact on BW, organ mass, or circulating hormones/metabolites in the calf. Evaluating offspring at later postnatal time points is warranted to determine if prenatal vitamin and mineral supplementation affects performance, health, metabolism, and efficiency of energy utilization in key metabolic tissues in the calf.

Dietary glycine supplementation activates mechanistic target of rapamycin signaling pathway in tissues of pigs with intrauterine growth restriction

The mechanistic target of rapamycin (mTOR) cell signaling pathway serves as the central mechanism for the regulation of tissue protein synthesis and growth. We recently reported that supplementing 1% glycine to corn- and soybean meal-based diets enhanced growth performance between weaning and market weights in pigs with intrauterine growth restriction (IUGR). Results of recent studies have revealed an important role for glycine in activating mTOR and protein synthesis in C2C12 muscle cells. Therefore, the present study tested the hypothesis that dietary glycine supplementation enhanced the mTOR cell signaling pathway in skeletal muscle and other tissues of IUGR pigs. At weaning (21 d of age), IUGR pigs and litter mates with normal birth weights (NBW) were assigned randomly to one of the two groups: supplementation with either 1% glycine or 1.19% l-alanine (isonitrogenous control) to a corn- and soybean meal-based diet. Tissues were obtained from the pigs within 1 wk after the feeding trial ended at 188 d of age to determine the abundances of total and phosphorylated forms of mTOR and its two major downstream proteins: eukaryotic initiation factor 4E-binding protein-1 (4EBP1) and ribosomal protein S6 kinase-1 (p70S6K). Results showed that IUGR decreased (P < 0.05) the abundances of both total and phosphorylated mTOR, 4EBP1, and p70S6K in the gastrocnemius muscle and jejunum. In the longissimus lumborum muscle of IUGR pigs, the abundances of total mTOR did not differ (P > 0.05) but those for phosphorylated mTOR and both total and phosphorylated 4EBP1 and p70S6K were downregulated (P < 0.05), when compared to NBW pigs. These adverse effects of IUGR in the gastrocnemius muscle, longissimus lumborum muscle, and jejunum were prevented (P < 0.05) by dietary glycine supplementation. Interestingly, the abundances of total or phosphorylated mTOR, 4EBP1, and p70S6K in the liver were not affected (P > 0.05) by IUGR or glycine supplementation. Collectively, our findings indicate that IUGR impaired the mTOR cell signaling pathway in the tissues of pigs and that adequate glycine intake was crucial for maintaining active mTOR-dependent protein synthesis for the growth and development of skeletal muscle.

Late gestational nutrient restriction in primiparous beef females: Performance and metabolic status of lactating dams and pre-weaning calves

Fall-calving primiparous beef females [body weight (BW): 451 ± 28 (SD) kg; body condition score (BCS): 5.4 ± 0.7] were individually-fed 100% (control; CON; n = 13) or 70% (nutrient restricted; NR; n = 13) of estimated metabolizable energy and metabolizable protein requirements from day 160 of gestation to calving. Post-calving, all dams were individually-fed tall fescue hay supplemented to meet estimated nutrient requirements for maintenance, growth, and lactation in Calan gates until day 149 of lactation, which limited calves to milk only. From day 150 of lactation until weaning at day 243, dams and calves were group-fed in drylots. Dam BW and metabolic status were determined every 21 d, and BCS and backfat (BF) were determined every 42 d of lactation until weaning. Pre-weaning calf BW, size, and metabolic status were determined every 21 d. Data were analyzed with nutritional plane, calving date, and calf sex (when P < 0.25) as fixed effects. Circulating metabolites included day and nutritional plane × day as repeated measures. We previously reported that post-calving, NR dams were 64 kg and 2.0 BCS less than CON, but calf BW and size at birth were not affected. During the first 147 d of lactation, NR dams gained more (P < 0.01) BW than CON and increased (P < 0.01) BCS, while CON decreased (P ≤ 0.01) BCS and BF. Previously, NR dams had lower (P < 0.01) circulating triglycerides on day 1 of lactation, tended to have lower (P = 0.08) triglycerides on day 21, and had lower (P ≤ 0.04) non-esterified fatty acids (NEFA) on days 21 and 243 than CON. Maternal glucose and urea N were not affected (P ≥ 0.73). At weaning, NR dams weighed 17 kg less (P = 0.15), were 0.67 BCS lower (P < 0.01), and tended to have less (P = 0.06) BF. Calves born to NR dams weighed less (P = 0.02) than CON by day 42 of age and were 13% smaller (P < 0.01) at weaning. Calf girth measures diverged (P ≤ 0.05) by day 21 of age, and skeletal size measures were less (P ≤ 0.08) for calves born to NR dams at most timepoints after day 63 of age. Calves born to NR dams tended to have lower (P = 0.09) circulating urea N pre-weaning than CON, but glucose, triglycerides, and NEFA were not affected (P ≥ 0.16). In summary, first-parity beef females that were nutrient restricted during late gestation experienced compensatory growth and gained body condition during lactation but were still thinner at weaning. Nutrient restriction reduced pre-weaning calf growth, likely due to decreased milk production.