A comparison of the anatomical and gastrointestinal functional development between gilt and sow progeny around birth and weaning1

Injecting postpartal gilts or sows with a supraphysiological dose of oxytocin: effects on sow and piglet performances

The goal of this project was to determine the effects of a supraphysiological dose of oxytocin given to gilts or multiparous sows 8 to 12 h after the end of farrowing on the performance of their progeny. Sows from three parity groups (1 = parity 1; 2 = parities 2, 3, and 4; 3 = parities 5 to 14) received no injection (CTL, controls; n = 17, 27, and 23 for parity groups 1, 2, and 3, respectively) or one intramuscular injection of 75 IU of oxytocin (OXY, n = 17, 24, and 26 for parity groups 1, 2, and 3, respectively) 8 to 12 h after birth of the last piglet. Colostrum samples were obtained 8 h after oxytocin injection in 18 sows from parity group 2 (CTL, n = 10; OXY, n = 8). Standard milk composition was measured as well as the Na/K ratio, and IGF-1, IgG, and IgA concentrations. The same sows were used to obtain blood samples from four male piglets of average litter body weight (BW) 8 h post-treatment to measure concentrations of IGF-1, IgG, and IgA. Piglets and sows were weighed at farrowing and weaning (day 21) and sow feed intake and piglet mortality were recorded. There was no effect of OXY on sow or piglet BW at any measured times and percent preweaning piglet mortality was not affected by OXY or parity. First-parity sows had lower BW than multiparous sows at both times (P < 0.001), and piglet average daily gain from birth to weaning was greater in parity group 2 compared with first-parity litters (P < 0.05). Average daily sow feed intake over the first week of lactation tended to be greater in OXY vs CTL sows (P = 0.07), and multiparous sows consumed more feed than first-parity sows on all weeks of lactation (P < 0.001). Eight hours after treatment, there was a tendency for colostral Na to be greater in OXY vs CTL sows (P = 0.06), and none of the measured variables in piglet blood were affected by treatment. In conclusion, injecting 75 IU of oxytocin 8 to 12 h after the birth of the last piglet did not prolong the period of colostrogenesis or improve the growth or survival of piglets and this was consistent across parities.

A comparative analysis of gastrointestinal tract barrier function and immune markers in gilt vs. sow progeny at birth and weaning

Progeny born to primiparous sows (gilt progeny; GP) have lower birth, weaning and slaughter weights than sow progeny (SP). GP also have reduced gastrointestinal tract (GIT) development, as evidenced by lower organ weights. Therefore, the aim of this experiment was to quantify changes in GIT barrier function that occur in birth and weaning, representing two major challenges to the young piglet. The effects of parity (GP vs. SP) in GIT barrier integrity function were quantified at four timepoints: birth (~0 h), 24 h after birth (24 h), 1-d preweaning (PrW), and 1-d postweaning (PoW) in commercially reared piglets. Due to inherent differences between newborn and weanling pigs, the results were analyzed in two cohorts, birth (0 vs. 24 h, n = 31) and weaning (PrW vs. PoW, n = 40). Samples of the stomach, jejunum, ileum, and colon were excised after euthanasia and barrier integrity was quantified by measuring transepithelial resistance (TER), macromolecular permeability, the abundance of inflammatory proteins (IL-8, IL-1β, and TNF-α) and tight junction proteins (claudin-2 and -3). Papp was characterized using a dual tracer approach comprising 4 KDa fluorescein isothiocyanate (FD4) and 150 kDa tetramethyl rhodamine isothiocyanate (T150)-labeled dextrans. Characteristic effects of the initiation of feeding and weaning were observed on the GIT with the initiation of feeding, such as increasing TER and reducing Papp at 24 h, consistent with mucosal growth (P = 0.058) This was accompanied by increased cytokine abundance as evidenced by elevations in TNF-α and IL-1β. However, GP had increased IL-8 abundance (P = 0.011 and 0.063 for jejunum and ileum respectively) at birth than 24 h overall. In the weaning cohort, jejunal and ileal permeability to FD4 was higher in GP (P = 0.05 and 0.022, respectively) while only higher ileal T150 was observed in GP (P = 0.032). Ileal claudin-2 abundance tended to be higher in SP overall (P = 0.063), but GP ileal claudin-2 expression was upregulated weaning while no change was observed in SP (P = 0.043). Finally, other than a higher jejunal TNF-α abundance observed in SP (P = 0.016), no other effect of parity was observed on inflammatory markers in the weaning cohort. The results from this study indicate that the GIT of GP have poorer adaptation to early life events, with the response to weaning, being more challenging which is likely to contribute to poorer postweaning growth.

Effect of yeast culture supplementation in sows during late gestation and lactation on growth performance, antioxidant properties, and intestinal microorganisms of offspring weaned piglets

Introduction

The effects of maternal addition of yeast cultures on offspring gut development and intestinal microorganisms are not yet known, so the aim of this study was to investigate the effects of maternal addition of yeast cultures to the diet of sows during late gestation and lactation on growth performance, antioxidant properties and intestinal microorganisms of offspring weaned piglets.

Methods

40 Landrace × Yorkshire sows (3-7 of parity) with similar backfat were randomly divided into two treatment groups: control diet (CON) and control diet +2.0 g/kg yeast culture (XPC), and the trial started on day 90 of gestation and ended on day 21 of lactation.

Results

The results showed that maternal addition of yeast culture significantly increased weaned piglet weight and mean daily gain (p < 0.05), with a tendency to increase litter weight gain (p = 0.083) and liver weight (p = 0.076) compared to the control group. The content of thymus malondialdehyde (MDA) was significantly higher (p < 0.05) and the content of colon total antioxidant capacity (T-AOC) was significantly lower (p < 0.05) in the offspring weaned piglets of the XPC group compared to the control group. The expression of thymus SOD1 and SOD2, spleen SOD1, jejunum SOD2, and colon GPX1, SOD1, and SOD2 were significantly downregulated in the XPC group of offspring weaned piglets compared with the control group (p < 0.05). The intestinal morphology and the content of short-chain fatty acids in colonic chyme did not differ between the two groups (p > 0.05). Compared with the control group, the XPC group significantly increased the relative abundance of colonic chyme Bacteroidetes (p < 0.05), tended to decrease the relative abundance of Lactobacillus (p = 0.078), and tended to increase the relative abundance of Alloprevotella (p = 0.055). The XPC group significantly upregulated Blautia and Fournierella (p < 0.05) and significantly downregulated Candidatus_Competibacter, Nitrospira, Dechloromonas, Haliangium, and Oscillospira (p < 0.05).

Discussion

In conclusion, maternal addition of yeast cultures improved the growth performance of offspring weaned piglets and changed the intestinal microbial community, but did not improve their antioxidant performance.

Supplementing oat hulls to the diet of suckling piglets altered their intestinal tract and colonic microbiota development

Current study evaluated the effect of a fine and coarsely ground insoluble dietary fibre source on the gastrointestinal development of suckling pigs. Oat hulls (OH) were selected as a model feedstuff, rich in cellulose, lignin, and insoluble dietary fibre. Three experimental supplemental diets were formulated: a finely ground, low fibre and nutrient dense diet served as control (CON). For the 2 high fibre diets, 15% heat-treated starch in CON was exchanged with OH, either finely (OH-f) or coarsely ground (OH-c). Litters of 10 primi- and multiparous sows (mean litter size 14.6 ± 0.84) were used. Within a litter, experimental diets were allotted to triplets of 4 piglets. From approximately 12 d of age, piglets' individual feed intakes were recorded 2 times per day when separated from their dam for 70 min. Piglets could suckle with their dam for the remainder of the day. On d 24 and 25, from the total pool of 120 piglets, seven healthy well-eating piglets per treatment were selected for post-mortem evaluation, resulting in 14 replicates per treatment. Consumption of OH-c and OH-f did not impede clinical health and production performance of piglets. The full stomach weights tended to be greater for OH-c compared to OH-f whereas CON was intermediate (P = 0.083). Supplementing OH significantly increased ileal villus height and caecal dry matter concentration (P < 0.05). For the colon, OH increased its length, contents weight, short-chain fatty acid concentration and reduced total bacterial count as well as γ-proteobacteria count and proportion (P < 0.05). The OH-c treatment specifically increased full gastrointestinal tract weight and caecum contents weight compared to piglets fed CON and OH-f. Furthermore, OH-c reduced colonic crypt depth when compared to OH-f (P = 0.018). In conclusion, supplementing OH to a diet for suckling piglets exerted subtle developmental effects on gastrointestinal morphology and colonic microbial community. These effects were largely independent from the particle size of the OH.

Animal board invited review: Factors affecting the early growth and development of gilt progeny compared to sow progeny

Progeny born to primiparous sows farrowing their first litter, often called gilt progeny (GP), are typically characterised by their poorer overall production performance than progeny from multiparous sows (sow progeny; SP). Gilt progeny consistently grow slower, are born and weaned lighter, and have higher postweaning illness and mortality rates than SP. Collectively, their poorer performance culminates in a long time to reach market weight and, ultimately, reduced revenue. Due to the high replacement rates of sows, the primiparous sow and her progeny represent a large proportion of the herd resulting in a significant loss for the pig industry. While the reasons for poorer performance are complex and multifaceted, they may largely be attributed to the immature age at which gilts are often mated and the significant impact of this on their metabolism during gestation and lactation. As a result, this can have negative consequences on the piglet itself. To improve GP performance, it is crucial to understand the biological basis for differences between GP and SP. The purpose of this review is to summarise published literature investigating differences in growth performance and health status between GP and SP. It also examines the primiparous sow during gestation and lactation and how the young sow must support her own growth while supporting the metabolic demands of her pregnancy and the growth and development of her litter. Finally, the underlying physiology of GP is discussed in terms of growth and development in utero, the neonatal period, and the early development of the gastrointestinal tract. The present review concludes that there are a number of interplaying factors relating to the anatomy and physiology of the primiparous sow and of GP themselves. The studies presented herein strongly suggest that poor support of piglet growth in utero and reduced colostrum and milk production and consumption are largely responsible for the underperformance of GP. It is therefore recommended that future management strategies focus on supporting the primiparous sow during gestation and lactation, increasing the preweaning growth of GP to improve their ability to cope with the stressors of weaning, selection of reproductive traits such as uterine capacity to improve birth weights and ultimately GP performance, and finally, increase the longevity of sows to reduce the proportion of GP entering the herd.

Assessment of visceral organ growth in pigs from birth through 150 kg

Visceral organs (VO) are essential for their role in the metabolism and distribution of consumed nutrients as well as other life functions in animals. Two experiments were conducted to assess the natural longitudinal changes that the VO undergo from birth through 150 kg body weight (BW). In Experiment 1, a total of 96 crossbred pigs were euthanized at birth (pre-suckle), d 1, 2, 3, 5, 7, 14, 21 (weaning), 22, 23, 24, 26, 28, 42, 49, and 63 of age. In Experiment 2, a total of 48 crossbred pigs were euthanized at 30, 50, 75, 100, 125, and 150 kg of BW. The absolute weight of VO, and the volume and length of the gastrointestinal tract (GIT) were measured. In both experiments, the absolute weight of VO, GIT length, and their volume increased (linear, quadratic, and/or cubic, P < 0.05) as BW and age increased. In Experiment 1, the relative weight of VO (liver, kidney, heart, and lung) decreased after initially increasing within the first week of life (linear, quadratic, and/or cubic, P < 0.05), whereas the relative weight of all VO decreased as BW increased in Experiment 2 (linear and/or quadratic, P < 0.05). The relative length of small intestine decreased and that of large intestine increased as age increased in Experiment 1 (linear and quadratic, P < 0.05), whereas the relative length of the small and large intestine in Experiment 2 were relatively constant at 80% and 20% of the total length of the intestine, respectively. As age and BW increased, the relative volume of the large intestine to the total volume of the GIT increased (linear and/or quadratic, P < 0.05), while the relative volume of the small intestine decreased (linear and/or quadratic, P < 0.05). In conclusion, results showed that both absolute and relative measurements (weight, volume, and length) of VO were dependent on the BW (age) of the pig.

Exposure to maternal feces in lactation influences piglet enteric microbiota, growth, and survival preweaning

It is known that gilt progeny performance is reduced compared with sow progeny. Previous research suggests that the presence of maternal feces in early life improves the health and survival of offspring. Therefore, we aimed to determine whether contact with feces from multiparous (MP) sows would improve the growth and survival of piglets born and reared on primiparous (P1) sows and if so, whether these differences are associated with the gut microbiota. Four treatments were applied for 10 days: Donor (n = 29) piglets had limited access to maternal feces as, each morning, sow feces were removed and placed in the crate of a P1 sow (P1-FT; n = 30 piglets) and P1-Con (n = 29) and MP-Con (n = 33) piglets had access to their own mothers’ feces. All piglets were weighed on days 1, 3, 10, and 18. Fecal samples were collected from a subset of sows (n = 10/treatment) 3 days post farrow and from two female piglets/litter on days 10 and 18 (n = 20/treatment) and subject to 16S rRNA amplicon analysis. Escherichia, Clostridium, Campylobacter, and Treponema were more abundant in MP sows, while P1 sows had a higher abundance of Lactobacillus and Prevotella. At 10 days, P1 progeny fecal microbiota differed, and growth and survival were reduced when compared with MP progeny. No treatment effect was observed for P1-FT piglets (P > 0.05). Donor piglets had a different fecal microbiota and improved weight and survival then all other treatments (P < 0.05). Overall, the removal of sow feces from the farrowing crate improved piglet microbiota development, growth, and survival.

Maintaining continuity of nutrient intake after weaning. I. Review of pre-weaning strategies

Weaning is a crucial phase of swine production marked by a multitude of biological and environmental stressors, which have a significant impact on immediate postweaning behavior and feed intake (FI). During this time, the piglet's gastrointestinal (GI) system is also undergoing extensive epithelial, immune, and nervous system development. In this review, our objective is to describe the different preweaning strategies that can be used to minimize nutrient intake disruption and improve FI in the immediate postweaning period. Reducing nutrient disruption postweaning can be accomplished through the implementation of management and nutritional strategies. Research consistently demonstrates that weaning older, more developmentally mature pigs helps prevent many of the adverse GI effects associated with weaning stress. Providing creep feed to pigs during lactation is another reliable strategy that has been shown to increase immediate postweaning FI by acclimating pigs to solid feed prior to weaning. Likewise, socialization by allowing pigs to mix before weaning improves social skills, minimizing mixing stress, and aggression-related injury immediately postweaning. Supplemental milk replacer has also been shown to elicit a positive response in preweaning growth performance, which may help to reduce preweaning mortality. While socialization and milk replacer are acknowledged to ease the weaning transition, these strategies have not been widely adopted due to labor and application challenges. Additionally, the cost of milk replacer and logistics of retrofitting farrowing houses to accommodate litter socialization have limited adaptation. Further exploration of maternal nutrition strategies, particularly fetal imprinting, is needed to better understand the implications of perinatal learning. Other areas for future research include, combining environmental enrichment with feeding strategies, such as large destructible pellets or play feeders, as well as determining at what time point producers should start socializing pigs before weaning. While more research is needed to develop strategic preweaning management programs, many of the strategies presented in this review provide opportunities for producers to minimize nutrient intake disruption by preventing feed neophobia, reducing stress, and easing the wean pig transition.

Evaluation of Sugarcane-Derived Polyphenols on the Pre-Weaning and Post-Weaning Growth of Gilt Progeny

Simple Summary

Gilt progeny are characterised by their poor lifetime growth performance compared with sow progeny. Various feeding strategies that employ the use of additives may be used to improve their growth. Gilts are said to be in increased oxidative stress throughout lactation, which may contribute to the reduced growth performance seen in their progeny. Furthermore, weaning is associated with increased inflammation, which can reduce growth after weaning. In this study, both late gestation/lactation diets and weaner diets were supplemented with a sugarcane extract rich in polyphenols owing to their anti-oxidative and anti-inflammatory properties to collectively improve the growth of gilt progeny. However, no improvements of growth performance of gilt progeny in both the pre-weaning and post-weaning periods were observed in response to polyphenol supplementation and sow progeny continuously outperformed gilt progeny. Furthermore, when inflammation was measured using the inflammatory cytokine interleukin-1β, no differences were found between the control and polyphenol supplemented group. However, gilt progeny exhibited reduced circulating interleukin-1β overall. In summary, gilt progeny experience persistent underperformance that may be coupled in part to poorer immune development and polyphenol supplementation did not overcome the persistent underperformance.

Abstract

Gilt progeny (GP) exhibit poorer growth compared with sow progeny (SP), particularly in the pre-weaning and post-weaning period. Late gestation/lactation sow diets and weaner diets were supplemented with 0.5% Polygain (POL), a sugarcane extract rich in polyphenols, to collectively improve GP growth in these periods. Gilts (n = 60) and sows (n = 68, parities 2 and 3) were fed a control or POL diet. Weaned GP (n = 79) and SP (n = 92) born to these dams were also fed either a CON or POL diet. Gilts litters weighed less than sow litters at birth and 21 days (p < 0.001 for both) and were not improved by POL (p = 0.80 and 0.54, respectively). GP were lighter than SP at day 7 and day 14 post-weaning (p < 0.001 for both) and were not improved by the POL diet at these timepoints (p = 0.61 and 0.97, respectively). Plasma interleukin-1β (IL-1β) was increased at weaning despite POL supplementation (p = 0.022) and GP had reduced IL-1β overall (p = 0.021). Overall, POL was unable to improve growth in GP and the attenuated immune response seen in GP could be contributing to their poor growth performance.

Milk lactoferrin concentration of primiparous and multiparous sows during lactation

Lactoferrin (LF), a sialylated iron-binding glycoprotein, has numerous vital physiological functions including immunomodulation and protection against a large group of microorganisms, improving neurodevelopment, health, growth performance, and milk production. Lactoferrin occurs in human milk at a higher concentration compared with bovine milk, but little information is available on LF concentrations in porcine milk and the effects of sow parity on milk LF concentration. The objective of this study was to quantify the LF concentration in porcine milk and to compare that concentration between gilts and sows during lactation. We also investigated the effect of genetic background and litter size of the female pig on the LF concentration of porcine milk. The milk from 30 gilts and 35 sows was collected at 3 stages of lactation, namely colostrum, transition, and mature milk. Standard and experimental samples were analyzed by ultra-high performance liquid chromatography using a diode array UV detector. The following findings were reported: (1) porcine milk contained significant levels of LF with the highest concentration in colostrum, which decreased by ∼62% and ∼67% in transitional and mature milk, respectively; (2) mature gilt milk contained a 22% higher concentration of LF compared with sow milk, which was statistically significant; (3) breed line had an overall significant effect on the LF content of porcine milk; however, when the breed was considered, no significant difference was observed; and (4) LF concentration of porcine milk was not significantly influenced by the litter size. The presence of LF in a higher concentration in porcine milk suggests that LF is an important constituent of pig milk that might contribute to the optimum growth and development of piglets.