Probiotic cocktails accelerate baicalin metabolism in the ileum to modulate intestinal health in broiler chickens

Background Baicalin and probiotic cocktails are promising feed additives with broad application prospects.While probiotic cocktails are known to enhance intestinal health,the potential synergistic impact of combining baicalin with probiotic cocktails on the gut health of broiler chickens remains largely unexplored.Therefore,this study aims to investigate the influence of the combined administration of baicalin and probiotic cocktails on the composition of ileal and cecal microbiota in broiler chickens to elucidate the underlying mechanisms responsible for the healthpromoting effects.Results A total of 3201-day-old male Arbor Acres broilers were divided into 4 groups,each with 8 replicates of 10 chicks per replicate.Over a period of 42 d,the birds were fed a basal diet or the same diet supplemented with 37.5 g/t baicalin(BC),1,000 g/t probiotic cocktails(PC),or a combination of both BC(37.5 g/t)and PC(1,000 g/t).The results demonstrated that BC+PC exhibited positive synergistic effects,enhancing intestinal morphology,immune function,and barrier function.This was evidenced by increased VH/CD ratio,sIgA levels,and upregulated expression of occludin and claudin-1(P<0.05).16S rRNA analysis indicated that PC potentiated the effects of BC,particularly in the ileum,where BC+PC significantly increased theα-diversity of the ileal microbiota,altered itsβ-diversity,and increased the relative abundance of Flavonifractor(P<0.05),a flavonoid-metabolizing bacterium.Furthermore,Flavonifractor positively correlated with chicken ileum crypt depth(P<0.05).While BC+PC had a limited effect on cecal microbiota structure,the PC group had a very similar microbial composition to BC+PC,suggesting that the effect of PC at the distal end of the gut overshadowed those of BC.Conclusions We demonstrated the synergistic enhancement of gut health regulation in broiler chickens by combining baicalin and probiotic cocktails.Probiotic cocktails enhanced the effects of baicalin and accelerated its metabolism in the ileum,thereby influencing the ileal microbiota structure.This study elucidates the interaction mechanism between probiotic cocktails and plant extract additives within the host microbiota.These findings provide compelling evidence for the future development of feed additive combinations.

Effects of tannic acid on the immunity and intestinal health of broiler chickens with necrotic enteritis infection

Background In broiler chickens,necrotic enteritis(NE)infection can reduce production performance.Tannic acid has shown great potential as a treatment of NE in broilers.However,the appropriate dosage of tannic acid in NE of broilers and the improvement effect on intestinal health are not very clear.In this study,we aimed to investigate the effects of different doses of tannic acid on the production performance,immunity,and intestinal health of broilers by constructing an NE model with C.perfringens infection and determining the appropriate dosage of tannic acid with regard to NE.Results Challenged birds showed significant reduction in body weight,villus height,and the ratio of villus height to crypt depth(P<0.05)and increase in the feed consumption gain ratio,intestinal lesion score,and crypt depth(P<0.05).The infection significantly reduced the relative Bacteroidota and Ligilactobacillus abundance(P<0.05)and increased the ratio of Firmicutes/Bacteroidota and cecal content of C.perfringens(P<0.05).Challenged birds fed diets supplemented with tannic acid showed significantly increased mRNA expression of nutrient transport carriers and intestinal barrier genes and growth performance and reduced serum zonulin and endotoxin levels(P<0.05).Addi-tion of tannic acid to the diet inhibited the inflammatory response by reducing the number of coccidia oocysts in feces and the content of C.perfringens in the cecum.Specifically,tannic acid reduced the serum levels of C reactive protein,myeloperoxidase,and specific IgY and ileal mucosal secretory immunoglobulin A levels in the ileal mucosa compared with those in the NE-infected birds.NE-infected birds fed diets supplemented with tannic acid also showed significantly increased relative Anaerocolumna,Thermoanaerobacterium,and Thermosinus abundance(P<0.05);their microbial composition and functional predictions were similar to those of the NC group.Conclusions Tannic acid in the diet alleviated NE by enhancing the intestinal barrier and absorption function.The recommended dietary tannic acid additive level is 500–750 mg/kg.Our study findings would be useful in reducing related economic losses in the broiler industry.

Effects of rearing system and antibiotic treatment on immune function,gut microbiota and metabolites of broiler chickens

Background:In China,cage systems with a high space utilization have gradually replaced ground litter systems,but the disease incidence of chickens in cages is higher.Broilers in the ground litter pens may be stimulated by more environmental microbes during the growth process and show strong immune function and status,but knowledge of which microbes and their metabolites play an immunomodulatory role is still limited.This study aimed to explore the differences and correlations in the immune function,gut microbiota and metabolites and the importance of gut microbiota of broilers raised in cages and ground litter pens.Methods:The experiment involved a 2×2 factorial arrangement,with rearing systems(cages or ground litter pens)and antibiotic treatment(with or without broad-spectrum antibiotics in drinking water)as factors.Results:The results showed that,compared with the cage group,the ground litter broilers had stronger nonspecific immune function(Macrophages%and NO in blood),humoral immune function(IgG in blood,LPS stimulation index in ileum)and cellular immune function(T%,Tc%,ConA stimulation index and cytokines in blood).Antibiotic(ABX)treat-ment significantly reduced nonspecific immune function(Macrophages%and NO in blood,iNOS and Mucin2 mRNA expression in ileum),humoral immune function(IgG in blood and sIgA in ileum)and cellular immune function(T%and cytokines in blood,Th and Tc ratio,TLRs and cytokines mRNA expression in ileum).Furthermore,the ground litter broil-ers had higherαdiversity of microbiota in ileum.The relative abundance of Staphylococcus,Jeotgalicoccus,Jeotgalibaca and Pediococcus in the ileum of ground litter broilers were higher.ABX treatment significantly reduced theαdiversity of ileal microbiota,with less Chloroplast and Mitochondria.In addition,the levels of acetic acid,isobutyric acid,kynurenic acid and allolithocholic acid in the ileum of ground litter broilers were higher.Spearman correlation analysis showed that Jeotgalibaca,Pediococcus,acetic acid,kynurenic acid and allolithocholic acid were related to the immune function.Conclusions:There were more potential pathogens,litter breeding bacteria,short-chain fatty acids,kynurenine,allolithocholic acid and tryptophan metabolites in the ileum of broilers in ground litter pens,which may be the reason for its stronger immune function and status.

In vivo and in vitro protective effect of arginine against intestinal inflammatory response induced by Clostridium perfringens in broiler chickens

Background:Necrotic enteritis is a widespread disease in poultry caused by Clostridium perfringens.We previously reported that dietary arginine supplementation protected the intestinal mucosa of broiler chickens with necrotic enteritis,but the related protective mechanisms remain unclear.The in vivo trial was designed as a 2×2 factorial arrangement to evaluated the effects of arginine supplementation on inflammatory responses,arginine transporters,arginine catabolism and JAK-STAT signalling pathway in broiler chickens challenged with C.perfringens or without C.perfringens.Furthermore,we validated the in vivo results using intestinal epithelial cells of chicken embryos.Results:C.perfringens infection markedly increased gut gross pathological and histopathological lesion scores,promoted liver C.perfringens invasion,reduced serum arginine levels,and elevated jejunal mucosal lysozyme activities(P<0.05),but these effects were significantly reversed by arginine supplementation in vivo(P<0.05).The challenge significantly increased serum procalcitonin levels,jejunal mucosal iNOS activities and jejunal IL-6,TGF-β3,cationic amino acid transporter(CAT)-1,and CAT-3 mRNA expression(P<0.05),whereas arginine supplementation significantly reduced jejunal IFN-γ,IL-1β,IL-6,IL-10,TGF-β3,and CAT-3 mRNA expression(P<0.05).Arginine supplementation significantly attenuated the C.perfringens challenge-induced increases in jejunal i NOS,arginase 2,arginine decarboxylase,arginine:glycine amidinotransferase,JAK1,JAK3,STAT1,and STAT6 mRNA expression(P<0.05).The in vitro experiment showed that C.perfringens challenge markedly increased cellular cytotoxicity and the mRNA expression of IL-1β,IL-8,IL-10,CAT-1 and CAT-3(P<0.05),which were significantly reversed by 50μmol/L and/or400μmol/L arginine pre-treatment(P<0.05).Conclusions:Arginine prevented C.perfringens challenge-induced circulated arginine deficiency,normalized intestinal arginine transport and catabolism,down-regulated JAK-STAT signalling pathway and attenuated the inflammatory response,which exerted protective effects on the intestine of broiler chickens.

Mannanase improves the growth performance of broilers by alleviating inflammation of the intestinal epithelium and improving intestinal microbiota

This experiment aimed to discuss and reveal the effect and mechanism of mannanase on intestinal inflammation in broilers triggered by a soybean meal diet.In this experiment,384 Arbor Acres broilers at1 d old were randomly divided into 3 treatment groups.The broilers were fed a corn-soybean meal basal diet,a low-energy diet(metabolizable energy reduced by 50 kcal/kg),and a low-energy diet supplemented with 100 mg/kg mannanase for 42 d.The low-energy diet increased feed conversion ratio from0 to 42 d,reduced ileal villus height and villus height-to-crypt depth ratio and upregulated the expression of nuclear factor kappa B(NF-κB)in the ileum(P<0.05).It also reduced cecal short-chain fatty acids(SCFA),such as acetic acid(P<0.05).Compared with low-energy diets,the addition of mannanase increased body weight at 42 d,promoted the digestibility of nutrients,and maintained the morphology and integrity of the intestinal epithelium of broilers(P<0.05).In addition,mannanase upregulated the expression of claudin-1(CLDN1)and zonula occludens-1(ZO-1)in the jejunum at 21 d,downregulated the expression of ileal NF-κB,and increased the content of isobutyric acid in the cecum of broilers(P<0.05).The results for the ileal microbiota showed that a low-energy diet led to a decrease in the relative abundance of Lactobacillus reuteri in the ileum of broilers.The addition of mannanase increased the relative abundance of Lactobacillus-KC45b and Lactobacillus johnsonii in broilers.Furthermore,a low-energy diet reduced the relative abundance of Butyricicoccus in the intestine of broilers and inhibited oxidative phosphorylation and phosphoinositol metabolism.Mannanase increased the relative abundance of Odoribacter,promoted energy metabolism and N-glycan biosynthesis,and increased the activities of GH3 and GH18.It is concluded that mannanase could improve the growth performance of broilers by reducing the expression of NF-κB in the ileum,increasing the production of SCFA in the cecum,suppressing intestinal inflammation,balancing the intestinal microbiota,reducing damage to the intestinal barrier,and improving the efficiency of nutrient utilization to alleviate the adverse effects caused by the decrease in dietary energy level.

Maternal supplementation with mulberry-leaf flavonoids improves the development of skeletal muscle in the offspring of chickens

The development of skeletal muscle is a crucial factor in determining the meat yield and economic benefits of broiler production.Recent research has shown that mulberry leaves and their extracts can be used to significantly improve the growth performance of livestock and poultry.The present study aims to elucidate the mechanisms involved in the regulation of skeletal muscle development in broiler offspring by dietary mulberry-leaf flavonoids(MLF)supplementation from the perspective of maternal effect theory.A total of 270 Qiling broiler breeder hens were randomly assigned to 3 treatments with different doses of MLF(0,30,60 mg/kg)for 8 weeks before collecting their fertilized eggs.The chicken offspring at 13 and 19 d of embryonic stage,and from 1 to 28 d old after hatching were included in this study.The results showed that maternal supplementation increased the breast muscle weight and body weight of the offspring at the embryo and chick stages(P<0.05).This was followed by increased cross-sectional area of pectoral muscle fibres at 14 d(P<0.05).Further determination revealed a tendency towards increased serum levels of insulin-like growth factor 1(IGF-1)(P=0.092)and muscle fibre count(P=0.167)at 1 d post-hatching following maternal MLF treatment,while serum uric acid(UA)was decreased at 14 d after hatching(P<0.05).Moreover,maternal MLF supplementation significantly up-regulated the mRNA expression of the myogenic regulatory factor Myf5 in skeletal muscle at the both embryonic and growth stages(P<0.05).The relative abundance of the downstream protein of BMPR2,Smad1 and p-Smad1/5/9 in the TGFβsignalling pathway was significantly increased by maternal MLF treatment.Meanwhile,the increased expression of the target protein p-mTOR in the breast muscle of the offspring chicks is in accordance with the improved growth rate of the breast and the body.In conclusion,maternal MLF supplementation can promote muscle protein metabolism and muscle fibre development of chick embryos through upregulation of Myf5 expression and BMP/p-Smad1/5/9 axis,thereby improving growth performance of slow growing broiler.

Comparative study of apparent metabolizable energy and net energy values of dephenolized cottonseed proteins for laying hens

Optimizing the energy utilization of nutrients and ensuring maximum benefits are continuous goals for livestock producers.The net energy(NE)value of feed reflects its nutritional value in the precision feeding system.An experiment was conducted to determine the apparent metabolizable energy(AME)and NE values of 3 types of dephenolized cottonseed protein(DCP)for Hy Line Brown hens aged 42 to 45 weeks using the reference diet substitution method.A reference diet based on corn soybean meal was used to meet the nutritional needs of Hy Line Brown laying hens.To render the crude protein and energy values of the 3 test diets similar,10.5%,12%,and 16%of the gross energy yielding ingredients from the reference diet were replaced with DCP 1,DCP 2,and DCP 3,respectively.The birds were fed 4 diets during a 7-d adaptation period.After the dietary adaptation period,2 birds per replicate from each treatment group were placed in an individual open circuit respiratory calorimetry chamber for a 3-d experimental period.Daily O_(2)consumption and CO_(2)production were recorded,and excreta samples were collected.The AME values of DCP 1,DCP 2,and DCP 3 were 3,049.05,2,820.13,and 2,982.31 kcal/kg of dry matter(DM),respectively.The NE values of DCP 1,DCP 2,DCP 3 were 1,475.77,1,910.31,and 1,905.37 kcal/kg of DM,respectively,and the NE:AME ratios were 48.40%,67.74%,and 63.89%,respectively.Our data show that the AME value of DCP does not reflect the nutritional value of the feed.The NE value of DCP with a high ME value was not necessarily high.

The ionome and proteome landscape of aging in laying hens and relation to egg white quality

The ionome is essential for maintaining body function and health status by participating in diverse key biological processes.Nevertheless, the distribution and utilization of ionome among different organs and how aging impacts the ionome leading to a decline in egg white quality remain unknown. Thus, we used inductively coupled plasma mass spectrometry(ICP-MS) to analyze 35 elements and their isotopic contents in eight organs of laying hens at 35, 72, and 100 weeks. Moreover, the magnum proteome, amino acids in egg white, and egg white quality were analyzed in laying hens at three different ages using 4D proteomics techniques, an amino acid analyzer, and an egg quality analyzer. Across the organs, we identified varying distribution patterns among macroelements(Mg24, Ca43/44, K39, and P31), transition metals(Zn64/66, Cu63/65, Fe56/57, and Mn55), and toxic elements(Pb208, Ba137, and Sr86). We observed an organ-specific aging pattern characterized by the accumulation of toxic elements(Pb208, Ba137, and Sr86) and calcification in the small intestine. Additionally, a decrease in the utilization of essential trace elements selenium(Se78/82) and manganese(Mn55) was noted in the oviduct. By analyzing ionome in tandem with egg quality, egg white amino acids, and proteome, we unveiled that the reduction of selenium and manganese concentrations in the magnum during the aging process affected amino acid metabolism, particularly tryptophan metabolism, thereby inhibiting the amino acid synthesis in the magnum. Furthermore, it accelerated the senescence of magnum cells through necroptosis activation, leading to a decline in the albumen secretion function of the magnum and subsequently reducing egg white quality.Overall, this study provides insights into the evolution of 35 elements and their isotopes across 8 organs of laying hens with age.It also reveals the elemental composition, interactions, and utilization patterns of these organs, as well as their correlation with egg white quality. The present study highlights the significance of ionome and offers a comprehensive perspective on the selection of ionome for regulating the aging of laying hens.