Folic acid perfusion administration reduced abdominal fat deposition in starter Arbor Acres broilers

Effect of Using Vitamin C Supplementation on Performance, Blood Parameters, Carcass Characteristics and Meat Quality of Broiler Chickens Under Heat Stress Condition: A Meta-Analysis

This meta-analysis was performed to evaluate the effects of vitamin C (Vit C) supplementation on broiler performance, blood parameters, carcass characteristics and meat quality under heat stress. Based on searches conducted on PubMed, Scopus, Google Scholar and Web of Science, 35 studies published in authoritative journals from 1985 to 2023 were meta-analysed. Heterogeneity was explored by meta-regression analysis. The results of this meta-analysis showed that the body weight (BW, SMD = +0.339, p = 0.003) and average daily gain (ADG, SMD = +0.381, p = 0.001) were significantly higher in the group receiving Vit C supplementation under heat stress compared to the control group. However, Vit C supplementation did not have a significant effect on feed intake (FI, SMD = +0.084, p = 0.245), but the results were significant for the feed conversion ratio (FCR, SMD = -0.529, p = 0.001). Breast, thigh, abdominal fat, carcass drop loss, liver, gizzard, heart and spleen were not affected by Vit C supplementation, but it has a significant effect on wing weight (SMD = -3.77, p = 0.001). The use of Vit C supplementation decreased triglyceride (SMD = -0.527, p = 0.001), cholesterol (SMD = -0.976, p = 0.001) and blood glucose (SMD = -0.734, p = 0.02) concentrations in the broiler under heat stress. Breast meat quality (L*, a* and b*) was not affected by Vit C supplementation. In the current study, most of the responses had high heterogeneity (I2 > 50%). The findings of this meta-analysis demonstrated that, in broiler chickens under heat stress, adding Vit C supplementation to the feed can enhance performance. However, Vit C did not have a significant effect on carcass characteristics and the quality of the breast meat of broiler chickens. According to our meta-analysis results, utilisation of 250 mg/kg of Vit C is recommended as an effective growth promoter in broiler under heat stress, and as an antioxidant compound, it had a positive effect on reducing blood TG and TC.

Butyric acid-based products, alone or in combination with hydroxy-selenomethionine, improve performance of laying hens in post-peak period by modulating their antioxidant, metabolic and immune status

This study aimed to evaluate the effects of butyrate, butyric glycerides (BG) and their combination with sodium selenite (SeNa) or hydroxy-selenomethionine (OH-SeMet) on the performance and egg quality of the laying hens in post-peak period as well as the potential mechanism. A total of 900 45-week-old Hy-Line brown laying hens were randomly allocated to 5 treatment groups (n = 10 replicates/diet, 18 hens/replicate). The hens were fed the basal diet supplemented with 0.3 mg/kg selenium from SeNa (Control), Control plus 240 mg/kg butyric acid from coated butyrate (CB), Control plus 240 mg/kg butyric acid from butyric glycerides, basal diet supplemented with 0.3 mg/kg selenium from OH-SeMet plus coated butyrate (CB+OH-SeMet) or butyric glycerides (BG+OH-SeMet), respectively, for 20 weeks. Serum, liver, isthmus, uterus, and jejunum were collected at the end of the trial for biochemistry, histology, redox status, and gene expression analysis. Compared with Control, diets supplemented with BG, CB+OH-SeMet and BG+OH-SeMet increased (p < 0.05) the average egg weight (0.6-2.2 %), while only BG+OH-SeMet increased (p < 0.05) the total egg weight (7.1 %) and egg-laying rate (4.6 %) and decreased (p < 0.05) the feed/egg ratio (5.0 %) throughout the whole experiment. Furthermore, BG+OH-SeMet reduced (p < 0.05) the content of IL-6 and alanine aminotransferase (15.4-32.5 %), while elevated (p < 0.05) the content of IgA, IgY, IgM and total protein (18.7-26.8 %) in the serum in comparison to the Control. Notably, dietary supplementation of BG+OH-SeMet performed more effective antioxidant capacity in decreasing (p < 0.05) malondialdehyde (16.4-27.9 %) content and increasing (p < 0.05) the activity of total antioxidant capacity and glutathione peroxidase (17.6-36.3 %) in various tissues. Further experiment revealed that dietary BG+OH-SeMet regulated the lipid metabolism by increasing (p < 0.05) the expression of Carnitine palmitoyltransferase 1A (CPT1A) and Lipoprotein lipase (LPL) in liver. In conclusion, diets supplemented with BG and OH-SeMet could improve the laying performance via the enhancement of antioxidant capacity and regulation of lipid metabolism.

Folic acid alleviates the negative effects of dexamethasone induced stress on production performance in Hyline Brown laying hens

Multiple stressors are believed to deteriorate production performance and cause substantial economic losses in commercial poultry farming. Folic acid (FA) is an antioxidant compound that can improve oocyte function and regulate gut microbiota composition. The current study was conducted to investigate the role of FA in alleviating stress and improving production performance. Sixty Hyline Brown laying hens at 21 weeks of age were randomly divided into three groups, with 10 replicates in each group and each replicate containing two chickens. Each group received basic diet and saline injection (Con group), basic diet with dexamethasone (DXM) injection (DXM group), or basic diet supplemented with FA (13 mg/kg in the premix) with DXM injection (FA group). The feeding trial lasted five weeks. Birds in the DXM and FA groups receiving subcutaneous DXM injections at a dosage of 4.50 mg/kg per day during the first seven days of the trial. Results showed that the levels of corticosterone, triglyceride, total cholesterol, and malondialdehyde in serum were significantly increased in the DXM group (P < 0.05), while the concentrations of FA and 5-methyltetrahydrofolate were decreased in the DXM group (P < 0.05). Laying hens in the DXM group had lower laying rates and egg quality, including egg weight, eggshell thickness, eggshell strength, albumen height, and Haugh units (P < 0.05). Conversely, FA alleviated these negative impacts. Through transcriptome analysis, a total of 247 and 151 differentially expressed genes were identified among the three groups, and 32 overlapped genes were further identified. Moreover, 44 and 59 differential metabolites were influenced by DXM and FA, respectively. Kyoto Encyclopedia of Genes and Genomes enrichment from the transcriptome and metabolomics showed that the reduced production performance may be due to the disturbance of oocyte production, calcium metabolism, and oxidative stress. Analysis of 16S rRNA gene amplicon sequences revealed the differential microbial composition and potential functional changes among the different groups. LEfSe analysis showed that Mucispirillum and Nautella were the predominant bacteria in the DXM group, while Clostridium was the predominant bacteria in the FA group. Functional prediction demonstrated that stressors enhanced fatty acid biosynthesis, while betaine biosynthesis and retinol metabolism were elevated in the FA group. Dietary FA reversed the elevated levels of bile acids (BA), including cholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid (P < 0.05). The DXM group showed an overall decrease in short-chain fatty acids (SCFA), but FA restored the concentrations of acetic acid, propionic acid, and isobutyric acid (P < 0.05). In conclusion, this study reveals that dietary FA can alleviate the degradation of production performance caused by stress through improving circulating antioxidant capacity, maintaining intestinal microbiota homeostasis, and regulating SCFA and BA biosynthesis. Thus, highlighting the prominent role of gut microbe-host interactions in alleviating multi-stresses.

Effects of in ovo feeding of vitamin C on embryonic development, hatching process, and chick rectal temperature of broiler embryos

Maternal nutritional status plays a crucial role in embryonic development and has persistent effects on postnatal chicks. Vitamin C (VC) plays an important role in embryonic and postnatal development involved in nutri-epigenetics. The present study was conducted to investigate the effects of in ovo feeding (IOF) of VC on embryonic development, egg hatching time, and chick rectal temperature. Trial 1 was conducted under normal incubation conditions without the IOF procedure and was designed to analyze the characteristics of embryonic development and establish the scoring standards for yolk absorption and the rupture of the shell membrane. The results showed that the relative weight of the embryo and residual yolk and the organ indexes were reliable indicators of embryonic development. Yolk absorption was scored 0, 1, 2, 3, and 4, with a higher score indicating more complete absorption. In addition, the rupture of the shell membrane was divided into two cases: YES and NO. Trial 2 included three groups, control (CON), normal saline (NS), and vitamin C (VC), and was designed to detect the effects of IOF of VC on the indicators in trial 1, as well as the plasma biochemical indicators. At embryonic age 11 (E11), each egg in the CON group was non-injected, each egg in the NS group was injected with 0.1 mL of sterile normal saline, and each egg in the VC group was injected with 0.1 mL of sterile normal saline containing 3 mg vitamin C. The whole day of E21 was evenly divided into three time periods: early (incubation hours 480-488), middle (incubation hours 488-496), and late (incubation hours 496-504). Among the CON, NS, and VC groups, the percentages of the early-hatched chicks (egg hatching time) were 29.31, 12.00, and 33.90%, respectively. The proportions of early and middle hatched chicks in these groups were 51.72, 42.00, and 38.27%, respectively. The rectal temperature of chicks was lower (p < 0.05) in the VC group than in the CON and NS groups. Compared to the NS group, the plasma biochemical indicators in the VC group showed significantly lower levels of alkaline phosphatase (ALP), total protein (TP), albumin (ALB), GLB, total bilirubin (TBIL), TBA, uric acid (UA), high-density lipoprotein cholesterol (HDL-C), and corticosterone (CORT) (p < 0.05). Additionally, alanine aminotransferase (ALT) had an increasing trend (p = 0.059) in the VC group. In conclusion, our data demonstrated that VC accelerated the hatching process and reduced chicks' rectal temperature, which may be related to the improvement of liver function and changes in metabolism, as indicated by blood biochemical indicators.

Impacts of dietary supplementation of chitosan nanoparticles on growth, carcass traits nutrient digestibility, blood biochemistry, intestinal microbial load, and meat quality of broilers

This study explores the impact of chitosan nanoparticles (CNP) on the performance, nutrient digestibility, blood biochemical, immunity, microbial load, carcass traits, and meat attributes of broilers. A total of 200 7-d-old Cobb chicks were distributed to 4 groups, each replicated 5 times, with 10 birds in each replicate. The experimental diets were as follows: First group was fed a basal diet only (control); 2nd, 3rd, and 4th groups received a basal diet supplemented with 0.2, 0.3, and 0.4 g CNP/kg of feed, respectively. Results showed that the body weight (BW) and body weight gain significantly improved (P < 0.05) in the birds belonging to the 0.4 CNP group compared to the other groups. The best feed efficiency (feed conversion ratio [FCR]) was found in the group supplemented with a 0.4-g CNP/kg diet. The digestibility coefficients for dry matter and crude protein were significantly higher, and ether extract was significantly lower in the 0.4 g CNP/kg group than in other groups (P < 0.05). Broiler birds of the 0.4 CNP group had significantly (P < 0.05) reduced serum cholesterol, AST, and ALT levels. The humoral immunity (increased serum IgG and IgM levels) tended to improve in birds fed 0.3 and 0.4 g CNP/kg of feed. Compared to the control, total bacterial load and coliform count decreased significantly (P < 0.05) by supplementing 0.4 g CNP in the diet. The dressing weight, breast weight, and abdominal fat % were altered in birds receiving dietary 0.4 g CNP/kg. The treatment with CNP at 0.4 g/kg feed enhanced the broiler meat quality by increasing the values for water holding capacity, ABTS [2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)], DPPH (2,2-diphenyl-1-picrylhydrazyl) while reducing the thiobarbituric acid reactive substances (TBARS) value. Based on the results above, it could be concluded that CNP supplementation at 0.4 g/kg is recommended as a beneficial feed additive for broiler chickens.

Nanopore sequencing demonstrates the roles of spermatozoal DNA N6-methyladenine in mediating transgenerational lipid metabolism disorder induced by excessive folate consumpton

Increased consumption of folic acid is prevalent due to its beneficial effects, but growing evidence emphasizes the side effects pointing to excessive dietary folate intake. The effects of excessive paternal folic acid consumption on offspring and its transgenerational inheritance mechanism have not been elucidated. We hypothesize that excessive folic acid consumption will alter sperm DNA N6-methyladenine (6mA) and 5-methylcytosine (5mC) methylation and heritably influence offspring metabolic homeostasis. Here, we fed roosters either folic acid-control or folic acid-excess diet throughout life. Paternal chronic folic acid excessive supplementation increased hepatic lipogenesis and lipid accumulation but reduced lipolysis both in the roosters and their offspring, which was further confirmed to be induced by one-carbon metabolism inhibition and gene expression alteration associated with the Peroxisome proliferator-activated receptor pathway. Based on the spermatozoal genome-wide DNA methylome identified by Nanopore sequencing, multi-omics association analysis of spermatozoal and hepatic DNA methylome, transcriptome, and metabolome suggested that differential spermatozoal DNA 6mA and 5mC methylation could be involved in regulating lipid metabolism-related gene expression in offspring chickens. This model suggests that sperm DNA N6-methyladenine and 5-methylcytosine methylation were involved in epigenetic transmission and that paternal dietary excess folic acid leads to hepatic lipid accumulation in offspring.

Comprehensive analysis of changes in expression of lncRNA, microRNA and mRNA in liver tissues of chickens with high or low abdominal fat deposition

1. The liver of chickens is a dominant lipid biosynthetic tissue and plays a vital role in fat deposition, particularly in the abdomen. To determine the molecular mechanisms involved in its lipid metabolism, the livers of chickens with high (H) or low (L) abdominal fat content were sampled and sequencing on long non-coding RNA (lncRNA), messenger RNA (mRNA) and small RNA (microRNA) was performed.2. In total, 351 expressed protein-coding genes for long non-coding RNA (DEL; 201 upregulated and 150 downregulated), 400 differentially expressed genes (DEG; 223 upregulated and 177 downregulated) and 10 differentially expressed miRNA (DEM; four upregulated and six downregulated) were identified between the two groups. Multiple potential signalling pathways related to lipogenesis and lipid metabolism were identified via pathway enrichment analysis. In addition, 173 lncRNA - miRNA - mRNA interaction regulatory networks were identified, including 30 lncRNA, 27 mRNA and seven miRNA.3. These networks may help regulate lipid metabolism and fat deposition. Five promising candidate genes and two lncRNA may play important roles in the regulation of adipogenesis and lipid metabolism in chickens.

Exploring optimal folic acid supplementation levels for lactating-pregnant rabbit does with different litter size

The lactation-pregnancy overlap in the industrialized 49-d breeding model increases nutritional demands for lactating-pregnant rabbit does. This study examined the effects of folic acid (FA) on the production performance and intestinal microflora of does with different litter sizes (LS, or number of kits). A total of 144 third-parity Hyplus does, aged 11 mo and weighing approximately 5.00 ± 0.07 kg, were divided into 4 treatment groups: control group (basal diet) and FA groups (basal diet + 15, 30, and 45 mg/kg FA). Does with LS of 5, 7, and 9 were selected after weaning. Our findings revealed that 1) Increased FA supplementation initially increased and then decreased the pre-lactation body weight of 21-d-old kits and prolactin (PRL) level of lactating does, while showing an inverse trend for estrogen (E) level of does. Increased LS significantly (P < 0.05) correlated with reduced milk yield of does. There was a significant (P < 0.05) interaction between FA and LS affecting PRL, E, growth hormone levels of does, and the pre-lactation body weight of 21-d-old kits; 2) Increased FA supplementation initially increased and then decreased the post-lactation body weight of 21-d-old and 35-d-old kits, elevated plasma FA (PFA) level of lactating-pregnant does, and significantly (P < 0.05) impacted the pregnancy rate of does. Increased LS was associated with reduced post-lactation body weight in 21-d-old and 35-d-old kits (P < 0.05). There was a significant (P < 0.05) interaction between FA and LS affecting plasma insulin-like growth factor-1 (IGF-1), homocysteine (HCY), PFA levels of does, the post-lactation body weight of 21-d-old kits, and weaning body weight of 35-d-old kits; and 3) FA supplementation promoted the growth of Ruminococcaceae and Rikenellaceae_RC9_gut_group in the feces of lactating-pregnant does, as well as the proliferation of Lachnospiraceae_NK4A136_group in the feces of pregnant does, suggesting enhanced anti-inflammatory properties and improved crude fiber breakdown. In summary, FA supplementation improved conception rates, regulated lactation-related hormone synthesis and secretion, increased body weight of 21-d-old kits, and enhanced intestinal anti-inflammatory functions.

Turmeric essential oil improves intestinal integrity, immunological parameters, and performance of broiler chickens under cyclic heat stress

This study aimed to examine whether dietary supplementation of broiler chickens with turmeric essential could mitigate the effects of cyclic heat stress conditions. Intestinal and immunological parameters and gene expression were evaluated during the grower phase. A total of 320 21-day-old male Cobb 500 broilers were distributed according to a completely randomized design with a 4 (diet) × 2 (environment) factorial arrangement and eight replications of five birds each. Dietary treatments consisted of a basal diet without essential oil (EO, negative control) and three diets containing low (100 mg kg-1), intermediate (200 mg kg-1), or high (300 mg kg-1) levels of turmeric EO. In the heat stress group, dietary supplementation with turmeric EO at 100 and 200 mg kg-1 improved body weight, feed conversion, breast yield, and relative liver weight. These supplementation levels reduced villus width, increased villus/crypt ratio, reduced the H/L ratio, and improved hepatic (HSP70 and SREBP1) and intestinal (OCLN) gene expression in birds under heat stress. These findings support the hypothesis that turmeric EO can be used to improve or restore intestinal integrity, modulate inflammation parameters, and, consequently, enhance the performance of broilers challenged by cyclic heat stress.

Age-Related Changes in Hepatic Lipid Metabolism and Abdominal Adipose Deposition in Yellow-Feathered Broilers Aged from 1 to 56 Days

The objective of this study was to evaluate the age-related changes in hepatic lipid metabolism, adipocyte hyperplasia, hypertrophy, and lipid metabolism in the abdominal adipose tissue of yellow-feathered broilers. Blood, liver, and abdominal adipose samples were collected on days 1, 7, 14, 21, 28, 35, 42, 49, and 56. Body, liver, and abdominal weight increased (p < 0.05) with age-related changes. The triacylglycerol content peaked on day 14, and total cholesterol content peaked on day 56. The adipocyte diameter and area peaked on day 56, and total DNA content peaked on day 7. The age-related changes in hepatic lipogenesis-related gene (ChREBP, SREBP-1c, ACC, FAS, SCD1) expression mainly occurred during days 1 to 21, hepatic lipolysis-related gene (CPT1, LPL, ApoB) expression mainly occurred during days 1 to 14, and abdominal adipose-deposition-related gene (PPARα, CPT1, LPL, PPARγ, C/EBPβ) expression occurred during days 1 to 14. These results demonstrated a dynamic pattern of hepatic lipid metabolism and abdominal adipose deposition in yellow-feathered broilers, which provides practical strategies to regulate hepatic lipid metabolism and reduce abdominal adipose deposition in yellow-feathered broilers.

Maternal Folic Acid Supplementation Improves the Intestinal Health of Offspring Porcine by Promoting the Proliferation and Differentiation of Intestinal Stem Cells

Maternal folic acid intake has important effects on offspring growth and development. The mechanism involved in the renewal of intestinal epithelial cells remains unclear. Thus, this study aimed to investigate the potential effect of maternal folic acid supplementation during gestation and lactation on the structural and functional development of the small intestine in piglet offspring. Twenty-four Duroc sows were assigned to a control group (CON) and a folic-acid-supplemented group (CON + FA, supplemented with 15 mg/kg of folic acid). The results showed that maternal folic acid supplementation throughout gestation and lactation significantly increased the body weight, serum folate level, and intestinal folate metabolism in piglets. It also improved the villus length, villus height-to-crypt depth ratio, and transcript levels of nutrient transporters (GLUT4, SNAT2, FABP2, and SLC7A5) in piglets' duodenum and jejunum. In addition, maternal folic acid supplementation increased Ki67-positive cells and the expression of proliferation-related marker genes (C-Myc, CyclinD1, and PCNA) in piglets' intestinal stem cells. It also boosted the expression of genes associated with mature secreted cells (ChrA, Muc2, Lyz, Vil1), indicating enhanced proliferation and differentiation of intestinal stem cells. These findings demonstrate that maternal folic acid supplementation enhances growth performance and gut health in piglet offspring by promoting epithelial cell renewal equilibrium.

Chitosan Oligosaccharides Alleviate Heat-Stress-Induced Lipid Metabolism Disorders by Suppressing the Oxidative Stress and Inflammatory Response in the Liver of Broilers

Heat stress has been reported to induce hepatic oxidative stress and alter lipid metabolism and fat deposition in broilers. Chitosan oligosaccharides (COSs), a natural oligosaccharide, has anti-oxidant, anti-inflammatory, and lipid-lowering effects. This study is conducted to evaluate dietary COS supplementation on hepatic anti-oxidant capacity, inflammatory response, and lipid metabolism in heat-stressed broilers. The results indicate that heat-stress-induced poor (p < 0.05) growth performance and higher (p < 0.05) abdominal adiposity are alleviated by COS supplementation. Heat stress increases (p < 0.05) serum AST and ATL activity, serum and liver MDA, TG, TC, and LDL-C levels, and the expression of hepatic IL-1β, IL-6, SREBP-1c, ACC, and FAS, while it decreases (p < 0.05) serum SOD and CAT activity, liver GSH-Px and SOD activity, and the expression of hepatic Nrf2, GPX1, IL-10, MTTP, PPARα, and CPT1. Nevertheless, COS supplementation decreases (p < 0.05) serum AST and ATL activity, serum and liver MDA, TG, TC, and LDL-C levels, and the expression of hepatic IL-1β, IL-6, SREBP-1c, ACC, and FAS, while it increases (p < 0.05) serum SOD and CAT activity, liver GSH-Px activity, and the expression of hepatic Nrf2, CAT, IL-10, LPL, MTTP, PPARα, and CPT1. In conclusion, COS could alleviate heat-stress-induced lipid metabolism disorders by enhancing hepatic anti-oxidant and anti-inflammatory capacity.

Mulberry leaf extract reduces abdominal fat deposition via adenosine-activated protein kinase/sterol regulatory element binding protein-1c/acetyl-CoA carboxylase signaling pathway in female Arbor Acre broilers

This experiment was carried out to investigate the mechanism of action of mulberry leaf extract (MLE) in reducing abdominal fat accumulation in female broilers. A total of 192 one-day-old female Arbor Acres (AA) broilers were divided into 4 diet groups, with each group consisting of 8 replicates with 6 birds per replicate. The diets contained a basal diet and 3 test diets with supplementation of 400, 800, or 1,200 MLE mg/kg, respectively. The trial had 2 phases that lasted from 1 to 21 d and from 22 to 56 d, respectively. The growth performance, abdominal fat deposition, fatty acid composition, serum biochemistry and mRNA expression of genes related to fat metabolism in liver were determined. The results showed that, 1) dietary supplementation with MLE had no significant impact on broilers final body weight, average daily gain (ADG), or feed to gain ration (F/G) (P > 0.05), but linearly reduced abdominal fat accumulation in both experimental phases (P < 0.05); 2) the total contents of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), such as palmitoleic acid, oleic acid, and eicosadienoic acid, were increased quadratically as a result of dietary supplements of 400, 800, and 1,200 mg/kg MLE (P < 0.01), while the total contents of saturated fatty acids (SFA), such as teracosanoic acid were decreased (P < 0.01); 3) the addition of 800 or 1,200 MLE mg/kg to the diet linearly reduced total cholesterol (TC) in the serum and liver (P < 0.05). Adenosine-activated protein kinase (AMPK) mRNA expression in the liver was quadratically increased by the addition of 800 or 1,200 MLE mg/kg to the diet (P < 0.05), and the mRNA expression of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), and acetyl-CoA carboxylate), fatty acid synthase (FAS) were linearly decreased (P < 0.05). In conclusion, MLE can be employed as a viable fat loss feed supplement in fast-growing broiler diets since it reduces abdominal fat deposition in female AA broilers via the AMPK/SREBP-1c/ACC signaling pathway. MLE can also be utilized to modify the fatty acid profile in female broilers (AA) at varied inclusion levels.

Dietary folic acid addition reduces abdominal fat deposition mediated by alterations in gut microbiota and SCFA production in broilers

Intensive selective breeding for high growth rate and body weight cause excess abdominal fat in broilers. Gut microbiota and folic acid were reported to regulate lipid metabolism. A total of 210 one-day-old broilers were divided into the control (folic acid at 1.3 mg/kg) and folic acid groups (folic acid at 13 mg/kg) to illustrate the effects of folic acid on growth performance, abdominal fat deposition, and gut microbiota, and the experiment lasted 28 d. Results revealed that dietary folic acid addition decreased abdominal fat percentage (P < 0.05) and down-regulated genes expression related to cell proliferation and differentiation in abdominal fat including IGF1, EGF, C/EBPα, PPARγ, PLIN1, FABP4 and PCNA (P < 0.05). Folic acid addition decreased caecal Firmicutes-to-Bacteroidetes ratio (P < 0.01) and increased the proportions of Alistipes, Oscillospira, Ruminococcus, Clostridium, Dehalobacterium and Parabacteroides (P < 0.05). Caecal acetic acid, and propionic acid contents were found to be higher under folic acid treatment (P < 0.05), which were negatively related to genes expression associated with adipocyte proliferation and differentiation (P < 0.05). Ruminococcus was positively correlated with caecal acetic acid content, and the same phenomenon was detected between propionic acid and Oscillospira and Ruminococcus (P < 0.05). Acetic acid and Oscillospira were identified to be negatively associated with abdominal fat percentage (P < 0.05). In conclusion, our data demonstrated that dietary supplementation of folic acid reduced fat deposition in broilers by inhibiting abdominal adipocyte proliferation and differentiation, which might be mediated by changes in gut microbiota and short chain fatty acid production.

Folate inhibits lipid deposition via the autophagy pathway in chicken hepatocytes

Excessive fat deposition affects the efficiency and quality of broiler meat production. To understand the molecular mechanism underlying abdominal fat content of broiler lines under divergent selection, we have attempted multiple genetics and genomics methods previously. However, the molecular mechanism of hepatic fat deposition remains largely unknown. On broiler lines divergently selected for abdominal fat content, we performed integrated mRNA and lncRNA sequencing on liver tissues. Key genes and signaling pathways related to the biosynthesis, elongation and metabolism of fatty acids, metabolic pathways, and folate biosynthesis were revealed. Then, primary hepatocytes (sex determined) were isolated and cultured, and treatment concentrations of folate and palmitic acid were optimized. Expression profiling on primary hepatocytes treated by folate and/or palmitic acid revealed that folic acid inhibited lipid deposition in a sex-dependent way, through regulating transcriptional and protein levels of genes related to DNA methylation, lipid metabolism (mTOR/SREBP-1c/PI3K), and autophagy (LAMP2/ATG5) pathways. Taken together, folate could interfere with hepatic lipid deposition possibly through the involvement of the autophagy pathway in broilers.

Folic Acid: Sources, Chemistry, Absorption, Metabolism, Beneficial Effects on Poultry Performance and Health

Recently, there has been an increasing interest in the study of the effects of folic acid (FA) on poultry because it was observed that FA could overcome problems in poultry health while improving its performance. FA, or folate, is a water-soluble B vitamin essential in poultry, so FA intake must be available in the feed. Sources of FA in feed come from plants or animals, and animal sources have relatively more stable FA. The ingested FA will be absorbed in the intestinal lumen and transported into the liver through the blood vessels. Therefore, FA has a positive effect on the performance and health status of poultry. The effect of FA on poultry performance is to increase reproductive tract development, FA content in eggs, hatchability, weight gain, average initial body weight, feed intake, relative growth rate, chick body weight, breast fillet percentage, and reduce FCR and white striping score. At the same time, the effect on poultry health influences antioxidant activities, thyroid hormones, blood biochemicals, anti-inflammatory gene expressions, and immune responses. The present review deals with FA sources, chemistry, absorption, metabolism, effects on performance, and poultry health, which are based on valid basic information.

Effects of high-dose folic acid on protein metabolism in breast muscle and performance of broilers

Attaining the optimal feed conversion ratio is the unaltered goal for poultry breeding, meat yield is one of the vital reference indexes for that. Folic acid is involved in protein metabolism by acting as a transmitter of one carbon unit, and the detail mechanism for the high-dose folic acid on growth of broiler skeletal muscle is still unclarified. The present study was conducted to investigate the effect and regulatory mechanism of folic acid on deposition and metabolism of protein in broiler breast muscle. A total of 196 one-day-old AA broilers were randomly assigned to 2 treatment groups. The chicks were fed corn-soybean diet with folic acid levels of 1.3 mg/kg (CON) or 13 mg/kg (FA), respectively. The results showed that high dose of folic acid significantly increased the body weight gain, average daily gain, average daily feed intake, and feed conversion ratio of broilers during 1 to 42 d. Compared with control group, folic acid statistically augmented the breast muscle ratio of broilers at 42 d, abdominal fat percentage was also decreased in FA group. Folic acid significantly increased the gene expression of folate receptor (FR) in duodenum and jejunum at 21 d, and its relative expression in jejunum of broilers at 42 d. Furthermore, relative expression of myogenin in broiler breast muscle was upregulated in folic acid group. Folic acid supplementation significantly enhanced the protein expression of phosphorylated serine/threonine kinase (AKT) and ribosomal protein S6 kinase 1 (S6K1) in the breast muscle of broilers at 21 d and 42 d. In conclusion, the results proved that high-dose folic acid activated the AKT/mammalian target of rapamycin (mTOR) pathway and increased the activity of phosphorylation of S6K1, thereby regulating the protein deposition in breast muscle. Meanwhile, the gene expression of the myogenic determinant factor was upregulated by folic acid and then promoted the growth of breast muscle. Consequently, the growth performance, meat production and feeding efficiency were improved of broilers by adding folic acid at 13 mg/kg.

Effect of dietary folic acid and energy density on immune response, gut morphology, and oxidative status in blood and breast muscle of broiler chickens

Folic acid (FA) plays essential roles in many metabolic functions and has been reported to have antioxidant effects. Therefore, dietary supplementation with high levels of FA may improve gut health and prevent potential oxidative stress caused by feeding a high energy density diet to broiler chickens. Broiler chickens were assigned into eight treatments, consisting of either a normal energy (NE) or high energy (HE) density diet, and four FA levels (2.2, 5, 10, and 15 ppm). Data were analyzed by SAS 16 GLM procedure. Birds-fed HE diets had increased (P < 0.05) plasma concentrations of calcium and albumin but reduced (P < 0.005) weights of ceca and bursa compared with those fed NE diets. Dietary supplementation with 10 ppm FA significantly increased (P < 0.05) birds’ heart weight and bile acid concentration. Folic acid and energy density interactions were significant for jejunal villus height (VH; P = 0.0226), villus width (VW; P < 0.0001), and crypt depth (CD; P = 0.0332). Among the NE group, birds fed 5–15 ppm FA had reduced (P < .0001) VW, while in the HE groups, 15 ppm FA supplementation resulted in an increased jejunal VH (P = 0.0317) compared with other treatments. In conclusion, dietary supplementation with increased levels of FA in HE diets could be beneficial for the intestinal health of broiler chickens.

Transcriptome Analysis of Effects of Folic Acid Supplement on Gene Expression in Liver of Broiler Chickens

Folic acid is a water-soluble B vitamin, and plays an important role in regulating gene expression and methylation. The liver is the major site of lipid biosynthesis in the chicken. Nevertheless, how gene expression and regulatory networks are affected by folic acid in liver of broilers are poorly understood. This paper conducted the RNA-seq technology on the liver of broilers under folic acid challenge investigation. First, 405 differentially expressed genes (DEGs), including 157 significantly upregulated and 248 downregulated, were detected between the control group (C) and the 5 mg folic acid group (M). Second, 68 upregulated DEGs and 142 downregulated DEGs were determined between C group and 10 mg folic acid group (H). Third, there were 165 upregulated genes and 179 downregulated genes between M and H groups. Of these DEGs, 903 DEGs were successfully annotated in the public databases. The functional classification based on GO and KEEGG showed that “general function prediction only” represented the largest functional classes, “cell cycle” (C vs. M; M vs. H), and “neuroactive ligand-receptor interaction” (C vs. H) were the highest unique sequences among three groups. SNP analysis indicated that numbers of C, M and H groups were 145,450, 146,131, and 123,004, respectively. Total new predicted alternative splicing events in C, M, and H groups were 9,521, 9,328, and 8,929, respectively. A protein-protein interaction (PPI) network was constructed, and the top 10 hub genes were evaluated among three groups. The results of real time PCR indicated that mRNA abundance of PPARγ and FAS in abdominal fat of M and H groups were reduced compared with the C group (P < 0.05). Ultramicroscopy results showed that folic acid could reduce lipid droplets in livers from chickens. Finally, contents of LPL, PPARγ, and FAS in abdominal fat were decreased with the folic acid supplmented diets (P < 0.01). These findings reveal the effects of folic acid supplemention on gene expression in liver of broilers, which can provide information for understanding the molecular mechanisms of folic acid regulating liver lipid metabolism.