Responses of growth performance,antioxidant function,small intestinal morphology and mRNA expression of jejunal tight junction protein to dietary iron in yellow-feathered broilers

This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per cage.The dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)O.Compared with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(P<0.0001).Adding 640 and 1,280 mg Fe kg^(-1)significantly decreased ADG(P<0.0001)and average daily feed intake(ADFI)(P<0.0001)compared with supplementation of 20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(P<0.0001),but MDA concentration in liver and jejunum increased linearly(P<0.05)or quadratically(P<0.05)with increased dietary Fe concentration.The villus height(VH)in duodenum and jejunum,and the ratio of villus height to crypt depth(V/C)in duodenum decreased linearly(P?0.05)as dietary Feincreased.As dietary Fe increased,the jejunal relative mRNA abundance of claudin-1 decreased linearly(P=0.001),but the jejunal relative mRNA abundance of zona occludens-1(ZO-1)and occludin decreased linearly(P?0.05)or quadratically(P?0.05).Compared with the supplementation of 20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA abundance.In summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein.

Molecular cloning and ontogenesis expression of fatty acid transport protein-1 in yellow-feathered broilers

Fatty acid transport protein-1 （FATP-1） is one of the important transporter proteins involved in fatty acid transmembrane transport and fat deposition. To study the relationship between FATP-1 mRNA expression and fat deposition, chicken （Gallus gallus） FATP-1 sequence was first cloned by rapid amplification of cDNA ends （RACE）. Tissue samples of chest muscle, leg muscle, subcutaneous fat, and abdominal fat were collected from six male and six female broilers each, at 22 days, 29 days, and 42 days, respectively. The tissue specificity and ontogenesis expression pattern of the FATP-1 mRNA of yellow-feathered broilers was studied by real-time reverse transcription polymerase chain reaction （RT-PCR）, and the fat deposition laws in different tissues were also compared. A 2,488 bp cDNA sequence of chicken FATP-1 was cloned by RACE （GenBank accession no. DQ352834）, including 547 bp 3＇ end untranslated region （URT） and 1,941 bp open reading frame （ORF）. Chicken FATP-1 encoded 646 amino acid residues, which shared 83.9% and 83.0% identity with those of human and rat, respectively. The results of quantitative PCR demonstrated a constant FATP-1 mRNA expression level in the chest muscle and subcutaneous fat of both male and female broilers at three stages, whereas the expression level of the FATP-1 mRNA in the leg muscle at 42 days was significantly higher than that at 22 days or 29 days. In the abdominal fat of male broilers, the gene expression significantly increased with age, whereas the female broilers showed a dramatic downregulation of FATP-1 expression in abdominal fat at 42 days. This suggested a typical tissue-and gender-specific expression pattern of chicken FATP-1, mediating the specific process of fatty acid transport or utilization in muscle and adipose tissues.

Retinol is involved in the intestinal regeneration and strengthens the intestinal barrier during refeeding in broiler chickens

Fasting is typically used before feeding metabolizable energy assessment in broilers.Previous studies have shown that fasting cause atrophy of the intestinal villus.Whether fasting affects intestinal permeability during refeeding by altering barrier function and nutrient absorption is of concern.Here,23-d-old broilers were randomly assigned to 5 treatments,fasted for 0,12,24,36,and 48 h,respectively,and then refed for 2 d,to study the impact of different duration of fasting on the intestinal regeneration and barrier function during refeeding.Results showed that the intestinal morphology in fasted birds was recovered in 2 d of refeeding at most.As fasting durations increased,enterocytes per intestinal villus were linearly and quadratically increased(both P<0.05),whereas goblet cells per intestinal villus was linearly decreased(both P<0.05).Besides,the mRNA level of lysozyme was linearly decreased as fasting durations increased during refeeding(both P<0.05),while quadratically increased mucin 2 was observed only after 1 d of refeeding(P<0.05).Linear increase effects were observed for claudin 2 and zonula occludens-1with increased fasting durations after 1 d of refeeding(all P<0.05),and linear and quadratical effects were observed for claudin 2 at 2 d of refeeding(both P<0.05).Besides,we found that intestinal permeability to creatinine,4 and 70 kD dextran were linearly and quadratically decreased with increased fasting durations at 6 h and 1 d of refeeding(all P<0.05).Furthermore,jejunum proteomic from birds refed for 6 h showed that birds fasted for 36 h showed increased antimicrobial peptides and upregulated retinol metabolism when compared to the nonfasted birds(P<0.05).Further study showed that retinyl ester catabolism was inhibited during fasting and enhanced during refeeding.Results of intestinal organoid culture showed that retinol benefits the cell proliferation and enterocyte differentiation.In conclusion,the intestinal permeability to small and large molecules was decreased during refeeding by strengthening the intestinal barrier function,and the activated retinol metabolism during refeeding is involved in the intestinal regeneration and strengthens the intestinal barrier.

Dietary Macleaya cordata extract supplementation improves the growth performance and gut health of broiler chickens with necrotic enteritis

Background The poultry industry needs effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE)caused by Clostridium perfringens.Methods The aim of this study was to investigate the effects of dietary supplementation with Macleaya cordata extract(MCE)on the immune function and gut microbiota of broilers with NE.A total of 2881-day-old broiler chicks were randomly assigned to a 2×2 factorial arrangement with two concentrations of dietary MCE supplementation(0 or 350 mg/kg of diet)and two disease challenge statuses(control or NE).Results The results revealed that NE significantly increased the feed conversion rate(FCR),mortality,intestinal lesion score,the levels of IL-1β,IL-17 and IFN-γ/IL-4 in serum and IL-17/IL-10 in the jejunal mucosa,m RNA levels of TLR2,IFN-γand p Ig R in the jejunum,and Clostridium perfringens concentrations in the cecum.NE significantly decreased the body weight(BW),body weight gain(BWG),jejunal villus height,V/C,m RNA level of AMPK-α1 in jejunum,IL-4 level in the jejunal mucosa and lactic acid bacteria abundance in the cecum.MCE significantly increased BW,BWG,jejunal villus height,V/C,m RNA levels of occludin,ZO-1 and AMPK-α1 in the jejunum,the levels of Ig A and Ig G in serum and IL-10 in the jejunal mucosa and m RNA levels of NF-κB,IL-10 and MHC-II in the jejunum.Additionally,MCE significantly decreased the FCR,mortality,intestinal lesion score,jejunal crypt depth,the levels of IFN-γand IL-17 in serum and IL-17/IL-10 in the jejunal mucosa,Clostridium perfringens concentrations in the cecum,and m RNA levels of IL-17/IL-10 in the jejunum.Moreover,NE significantly increased the abundance of bacteria that are associated with inflammation,obesity and depression(Alistipes,Barnesiella,Intestinimonas,RF39 and UCG-005)and significantly decreased the abundance of short-chain fatty acid(SCFA)-producing bacteria(Anaerotruncus,Butyricicoccus and Bacteroides)in the cecum.MCE significantly increased the abundance of SCFA-producing bacteria(Streptococcus,Ruminococcus_torques_group and Lachnospiraceae_NK4A136_group)and significantly reduced the abundance of bacteria that are associated with inflammation and obesity(Alistipes,Barnesiella and UCG-010)in the cecum.In the cecum of broilers with NE,the relative abundance of Barnesiella and Alistipes was higher and that of Lachnoclostridium and Shuttleworthia was lower.Interestingly,these trends were reversed by the addition of MCE to the diet.Spearman correlation analysis showed that Barnesiella and Alistipes were associated with enhanced intestinal inflammation and inhibited growth performance,whereas Lachnoclostridium and Shuttleworthia were associated with anti-inflammatory effects.Conclusions MCE ameliorated the loss of growth performance in broiler chickens with NE,probably by regulating the intestinal barrier,immune function,and gut microbiota.

Effects of Supplemental Glutamine and Lysine on Growth Performance of Broiler Chickens

The optimum levels of Lysine and Glutamine needed for growth performance and maintenance of the chicken broilers were evaluated in a randomized 3 × 4 factorial arrangement of dietary treatments. The battery cages measured 99 × 66 × 25 cm that can be sufficient for 5 birds. Day old Chicken broilers totaling 180 were assigned to dietary treatments comprising of 3 concentrations of Lysine (0.85, 1.14, and 1.42) each in combination with 4 concentrations of Glutamine (0, 1, 2, and 3). Each dietary treatment was replicated 3 times and each replication had 5 birds. The birds were given feed and water ad libitum with a 23-hour light regimen for a period of 4 weeks. Then, the experimental birds were evaluated for body weight gain, feed consumption, and feed conversion in order to determine their optimum requirement for dietary Lysine and Glutamine. Based on the findings of this study, the highest performance was observed in birds fed the diet supplemented with 1.42 lysine and 1% glutamine, but the highest improvement in feed conversion was observed in diet contain 1.14 and 1.42 with 1% and 3% glutamine, respectively. Birds fed 1.42 lysine and 1% glutamine had the highest total body weight gain and feed consumption. The lysine requirements in the diet for Chicken are between 1.14 and 1.42 with glutamine level of 1%.

Effects of Bacillus coagulans supplementation on the growth performance and gut health of broiler chickens with Clostridium perfringens-induced necrotic enteritis

Background: The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE) due to Clostridium perfringens.Methods: This study was conducted to investigate the effects of feeding Bacil us coagulans on the growth performance and gut health of broiler chickens with C. perfringens-induced NE. Two hundred and forty 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two dietary B. coagulans levels(0 or 4 × 109 CFU/kg of diet) and two disease chal enge statuses(control or NE chal enged).Results: NE-induced reduction in body weight gain was relieved by the addition of B. coagulans into broiler diets compared with the NE-infected birds. NE infection damaged intestinal morphological structure, promoted intestinal C.perfringens growth and liver invasion, and enhanced anti-C. perfringens specific sI gA concentrations in the gut and specific IgG levels in serum compared with the uninfected birds. NE infection significantly(P < 0.05) decreased mucin-2(at 14 d post-infection(DPI), tol-like receptor 2(TLR2, at 7 and 14 DPI), TLR4(at 7 and 14 DPI), tumor necrosis factor super family15(TNFSF15, at 7 and 14 DPI), lysozyme(LYZ, at 14 DPI) and fowlicidin-2(at 7 and 14 DPI) mR NA levels, whereas it dramatical y(P = 0.001) increased IFN-γ mR NA levels at 7 DPI. However, chal enged birds fed diets supplemented with B.coagulans showed a significant(P < 0.01) decrease in gut lesion scores, decreased C. perfringens numbers in the cecum and liver, and an increase in fowlicidin-2 mR NA levels in compared with the uninfected birds. In addition, compared with the non-supplemented group, dietary inclusion of B. coagulans improved intestinal barrier structure, further increased specific sI gA levels and alkaline phosphatase(IAP) activity in the jejunum, enhanced the expression of jejunum lysozyme mR NA, and inhibited the growth, colonization, and invasion of C. perfringens; in contrast, it reduced serum-specific IgG concentrations and jejunum IFN-γ mR NA levels.Conclusion: These results indicated that dietary B. coagulans supplementation appeared to be effective in preventing the occurrence and reducing the severity of C. perfringens-induced NE in broiler chickens.

Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility,apparent metabolizable energy and apparent ileal amino acid digestibility

Background: The study aimed to determine the apparent total tract digestibility coefficients(ATTDC) of nutrients, the apparent metabolizable energy(AME and AMEn) and the amino acid(AA) apparent ileal digestibility coefficients(AIDC)of a partially defatted(BSFp) and a highly defatted(BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg(w/w) of the basal diet with BSFp or BSFh, respectively.Results: Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly(P < 0.05) different between the two BSF meals, with higher levels for BSFp(16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility(0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal(P < 0.05).Conclusions: Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

Effects of thymol and carvacrol supplementation on intestinal integrity and immune responses of broiler chickens challenged with Clostridium perfringens

Background： Necrotic enteritis caused by Clostfidium perffingens infection leads to serious economic losses in the global poultry production. In the present study, we investigated the protective effects of essential oils （EO, which contained 25 % thymol and 25 % carvacrol as active components） supplementation on growth performance, gut lesions, intestinal morphology, and immune responses of the broiler chickens infected with C. perfringens. A total of 448 1-day-old male broiler chicks were allocated into eight treatment groups following a 4 x 2 factorial arrangement with four dietary EO dosages （0, 60, 120, or 240 mg/kg） and two infection status （with or without C. perfringens challenge from d 14 to 20）. Results： The challenge did not impair the growth performance of birds, but induced gut lesions and increased crypt depth in the ileum （P ≤ 0.05）. It also down-regulated the claudin-1 and occludin mRNA expression （P ≤0.05）, up-regulated the mRNA expression of interleukin-113 （P≤ 0.05）, tended to increase the toll-like receptor （TLR） 2 mRNA expression （P 〈 0.10） in the ileum, and enhanced the mucosal secretory IgA production （P 〈 0.05）. In the challenged birds, dietary EO supplementation linearly alleviated the gut lesions and improved the ratio of villus height to crypt depth （P ≤0.05）, and the supplementation of 120 and 240 mg/kg EO increased the serum antibody titers against Newcastle disease virus （P≤ 0.05）. Regardless of challenge, the EO supplementation showed a tendency to linearly elevate the feed conversion efficiency between 14 and 28 d of age as well as the occludin mRNA expression （P〈 0.10）, and linearly inhibited the mRNA expression of TLR2 and tumor necrotic factor-o in the ileum （P≤ 0.05）. Conclusions： The dietary supplementation of EO could alleviate the intestinal injury by improving intestinal integrity and modulating immune responses in the C. perffingens-challenged broiler chickens.

Black soldier fly defatted meal as a dietary protein source for broiler chickens:Effects on growth performance,blood traits,gut morphology and histological features

Background: The present study has evaluated the effects of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens L.; HI) larva meal on the growth performance, blood parameters and gut morphology of broiler chickens. A total of 256 male broiler chickens(Ross 308) were reared from d 1 to d 35 and assigned to4 dietary treatments(8 replicates/treatment and 8 birds/replicate). HI larva meal was included at increasing levels(0, 5%, 10% and 15%; HI0, HI5, HI10 and HI15, respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter(1–10 d), growing(10–24 d) and finisher(24–35 d). Two birds per pen were slaughtered at d 35 and morphometric investigations and histopathological alterations were performed.Results: The live weight(LW) showed linear and quadratic responses to increasing HI larva meal(maximum for HI10 group). Average daily gain(ADG) showed a linear and quadratic responses to HI meal(maximum for HI10 group) during starter and growing periods. A linear decrease was observed for ADG during the finisher period. The daily feed intake(DFI) showed a linear and quadratic effect during the starter period(maximum for HI10 group).Linear and quadratic responses were observed for the feed conversion ratio(FCR) in the growing period and for the whole period of the experiment. The FCR showed a linear response in the finisher period(maximum for HI15).No significant effects were observed for the blood and serum parameters, except for the phosphorus concentration,which showed linear and quadratic responses as well as glutathione peroxidase(GPx) activity, the latter of which showed a linear response. The HI15 birds showed a lower villus height, a higher crypt depth and a lower villus height-to-crypt depth ratio than the other groups.Conclusions: Increasing levels of dietary HI meal inclusion in male broiler chickens may improve the LW and DFI during the starter period, but may also negatively affect the FCR and gut morphology, thus suggesting that low levels may be more suitable. However, no significant effects on the haematochemical parameters or histological findings were observed in relation to HI meal utilization.

Effects of dietary supplementation of probiotic,Clostridium butyricum,on growth performance,immune response,intestinal barrier function,and digestive enzyme activity in broiler chickens challenged with Escherichia coli K88

Background： Colibacillosis caused by enterotoxigenic Escherichia coil （E. coil} results in economic losses in the poultry industry. Antibiotics are usually used to control colibacillosis, however, E. coli has varying degrees of resistance to different antibiotics. Therefore the use of probiotics is becoming accepted as an alternative to antibiotics. In this study, we evaluated the effects of Clostfidium butyricum （C. butyficum） on growth performance, immune response, intestinal barrier function, and digestive enzyme activity in broiler chickens challenged with Eschefichia coli （E. coil） K88. Methods： The chickens were randomly divided into four treatment groups for 28 days. Negative control treatment （NC） consisted of birds fed a basal diet without E. coil K88 challenge and positive control treatment （PC） consisted of birds fed a basal diet and challenged with E. coil K88. C. buO/ricum probiotic treatment （CB） consisted of birds fed a diet containing 2 x 107 cfu C. buO/ricum/kg of diet and challenged with E. coil K88. Colistin sulfate antibiotic treatment （CS） consisted of birds fed a diet containing 20 mg colistin sulfate/kg of diet and challenged with E. coil K88. Results： The body weight （BW） and average day gain （ADG） in the broilers of CB group were higher （P 〈 0.05） than the broilers in the PC group overall except the ADG in the 14-21 d post-challenge. The birds in CB treatment had higher （P 〈 0.05） concentration of tumor necrosis factor-a （TNF-a） at 3 and 7 d post-challenge, and higher （P 〈 0.05） concentration of interleukin-4 （IL-4） at 14 d post-challenge than those in the PC treatment group. The concentration of serum endotoxin in CB birds was lower （P 〈 0.05） at 21 d post-challenge, and the concentrations of serum diamine oxidase in CB birds were lower （P 〈 0.05） at 14 and 21 d post-challenge than in PC birds. Birds in CB treatment group had higher （P 〈 0.05） jejunum villi height than those in PC, NC, or CS treatment at 7, 14, and 21 d post-challenge. In comparison to PC birds, the CB birds had lower （P 〈 0.05） jejunum crypt depth during the whole experiment. The birds in CB or CS treatment group had higher （P 〈 0.05） activities of amylase and protease at 3, 7, and 14 d post-challenge, and higher （P 〈 0.05） activity of lipase at 3, 7 d post-challenge than PC birds.

Influence of starch sources and dietary protein levels on intestinal functionality and intestinal mucosal amino acids catabolism in broiler chickens

Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production.Reduced-crude protein diets depress environmental pollution and feeding cost,but the challenge to their adoption is maintaining digestive function and growth performance of birds.The present study was conducted to evaluate the influence of different dietary starch sources and protein levels on intestinal functionality and mucosal amino acid catabolism.Methods: Six dietary treatments,based on maize and soybean meal,were offered to 360 AA+male chicks from 6 to 35 d post-hatch as a 3 × 2 factorial array.Either waxy rice or amylose was added to a conventional maize-soy diet to provide three sources of starch with different digestion rates and relatively high and low dietary protein levels.Growth performance,parameters of intestinal functionality and concentrations of free amino acid in the portal circulation were determined.Results: In the grower phase,starch source influenced(P < 0.02) weight gain as diets containing amylose supported significantly higher weight gains than waxy rice.Significant increase of ileal ATP concentrations and Na^+/K^+-ATPase activity were found in amylose treatment.Also,amylose decreased BrdU positive cell numbers and down-regulated m RNA expression for CASP-3.GOT activity in the ileum was higher(P < 0.01) in birds offered low protein diets and there was a trend(P = 0.057) for waxy rice as a starch source to increase ileal GOT activities.There was a significant influence on the concentration of seventeen amino acids in the portal circulation with tryptophan the one exception.Waxy rice as a starch source generated 13.6% and 22.4% numerically higher concentrations of non-essential amino acids than maize and amylose,respectively.Conclusions: Amino acid catabolism in the gut mucosa is subject to nutritional regulation.Given that amino acids can be spared from catabolism in the gut mucosa by supplementation of amylose,it follows their post-enteral availability would be improved and intestinal energy would be derived more efficiently from glucose.

In vitro antibacterial activity of thymol and carvacrol and their effects on broiler chickens challenged with Clostridium perfringens

Background： In the post-antibiotic era, essential oils （EO） are promising alternatives to growth-promoting antibiotics. The aim of the present study was to investigate the antibacterial activities of an EO product and its components thymol and carvacrol in vitro, and the efficacy of EO to control Clostridium perffingens challenge in broiler chickens. Results： The in vitro minimum inhibitory concentration assay showed strong antibacterial activity of the EO product, thymol, and carvacrol against pathogenic Escherichia col~, C. perffingens, and Salmonella strains, and weak activity towards beneficial Lactobacillus strains. Besides, an additive effect was observed between thymol and carvacrol. The in vivo study was carried out with 448 male broiler chicks following a 4 x 2 factorial arrangement to test the effects of EO supplementation （0, 60, 120, or 240 mg/kg EO in wheat-based diet）, pathogen challenge （with or without oral gavage of C. perfr/ngens from day 14 to day 20） and their interactions. Each treatment consisted of eight replicate pens （seven birds/pen）. The challenge led to macroscopic gut lesions, and resulted in a significant increase in ileal populations of C. perffingens and Eschefichia subgroup （P ≤ 0.05） on day 21. Dietary EO supplementation did not influence C. perfringens numbers, but linearly alleviated intestinal lesions on day 21 and 28 （P= 0.010 and 0.036, respectively）, and decreased Eschefichia populations in ileum with increased EO dosages （P = 0.027 and 0.071 for day 21 and 28, respectively）. For caecum, EO quadratically influenced Lactobacillus populations on day 21 （P = 0.002）, and linearly decreased the numbers of total bacteria and Eschefichio on day 28 （P = 0.026 and 0.060, respectively）. Mean thymol and carvacrol concentrations in the small intestine were 0.21 and 0.20 μg/g in intestinal digesta （wet weight）, respectively, for birds fed 60 mg/kg EO, and 0.80 and 0.71 μg/g, respectively, for birds fed 240 mg/kg EO. Conclusions： These results indicated that dietary EO supplementation could affect intestinal microbiota and alleviate intestinal lesions in broilers, which may contribute in controlling C. perffingens infection in broiler chickens.

Intestinal toxicity of deoxynivalenol is limited by supplementation with Lactobacillus plantarum JM113 and consequentially altered gut microbiota in broiler chickens

Background: Limited research has focused on the effect of Lactobacillus on the intestinal toxicity of deoxynivalenol(DON).The present study was conducted to investigate the role of Lactobacillus plantarum(L.plantarum) JM113 in protecting against the intestinal toxicity caused by DON.Methods: A total of 144 one-day-old healthy Arbor Acres broilers were randomly distributed into 3 treatments,including the CON(basal diet),the DON(extra 10 mg/kg deoxynivalenol),and the DL(extra 1 × 109 CFU/kg L.plantarum JM113 based on DON group) treatments.The growth performance,organ indexes,intestinal morphology,pancreatic digestive enzymes,intestinal secreted immunoglobulin A(sIgA),jejunal transcriptome,and intestinal microbiota were evaluated.Results: Compared with the CON and DL groups,the DON supplementation altered intestinal morphology,especially in duodenum and jejunum,where villi were shorter and crypts were deeper(P < 0.05).Meanwhile,the significantly decreased mRNA expression of jejunal claudin-1 and occludin(P < 0.05),ileal rBAT and jejunal GLUT1 of 21-day-old broilers(P < 0.05),as well as duodenal PepT1 and ileal rBAT of 42-day-old broilers were identified in the DON group.Moreover,supplementation with L.plantarum JM113 could increase duodenal expression of IL-10 and IL-12 of 21-dayold broilers,ileal s IgA of 42-day-old broilers,and the bursa of Fabricius index of 21-day-old broilers.Further jejunal transcriptome proved that the genes related to the intestinal absorption and metabolism were significantly reduced in the DON group but a significant increase when supplemented with extra L.plantarum JM113.Furthermore,the bacteria related to nutrient utilization,including the Proteobacteria,Escherichia,Cc-115(P < 0.05),Lactobacillus and Prevotella(P < 0.1) were all decreased in the DON group.By contrast,supplementation with L.plantarum JM113 increased the relative abundance of beneficial bacterium,including the Bacteroidetes,Roseburia,Anaerofustis,Anaerostipe,and Ruminococcus bromi(P < 0.05).Specifically,the increased abundance of bacteria in the DL group could be proved by the significantly increased caecal content of propionic acid,n-Butyric acid,and total short-chain fatty acid.Conclusions: L.plantarum JM113 enhanced the digestion,absorption,and metabolic functions of the gut when challenged with DON by reducing the injury to intestinal barriers and by increasing the abundance of beneficial bacterium.

Effects of Ultraviolet Radiation on Skeleton Development of Broiler Chickens

Seven hundred and twenty one-day-old AA broiler chickens were randomly allocated into two groups （male and female for half）, and put into two identical closed houses with different lighting programs. The first house was illuminated by using common incandescence light, and the second one was added with ultraviolet radiation light from the second week onwards. The birds lived in a floor with litters and free access to feed and water. Temperature, humidity and immune programs in the two houses were similar. The results showed that under ultraviolet radiation, the growth speed of skeleton increased （the shank length was significantly increased in the third week, P〈0.05; the leg muscle weight was significantly improved by 3.87%, P〈 0.05）; the skeleton quality improved （the density of skeleton mineralization was significantly increased by 6.11%, P 〈 0.01; serum calcium, phosphorus, and alkaline phosphatase activity were all improved）; and the growth performance was improved （feed conversion ratio was improved by 1.4% averagely; the uniformity of body weight, the shank length, the inclined body length and body height were significantly improved） in broiler chicken.

Progress towards reduced-crude protein diets for broiler chickens and sustainable chicken-meat production

The prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein(CP)diets and sustainable chicken-meat production may be best achieved.Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions;moreover,they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents.The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed.The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids.Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine,this emphasises the value of so-called“non-essential”amino acids.Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed,although the functions of insulin in avian species require clarification.Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets;if so,the identification of the underlying reasons for this difference should be instructive.Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance.Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance.If progress in these directions can be realised,then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.

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.

Effects of age on immune function in broiler chickens

Background:There are many diseases in poultry,many of which are caused by poor immune function.It is not clear how cytokines and various immune cell functions change with age in modern broilers.The purpose of this study was to explore the patterns of development of the immunity of the broiler chickens in cage.Results:The results showed that there were 3 development patterns of immunity in the broiler chickens.The first pattern was Down-Up.Cytokines and some immune indicators first decreased and then increased,and the lowest levels of immunity basically occurred from d 6 to 13.The second pattern was Up-Down,and from d 30 to 34,the highest levels of non-specific cellular immunity components,such as the peripheral blood mononuclear macrophage ratio,specific cellular immunity components,such as the peripheral blood helper T(Th)cell ratio and T cell and B cell proliferation activity,and mucosal immunity components,such as the ileal CD4,TGF-β1 and IgA mRNA levels,were observed.The third pattern was Up-Up,and the levels of the non-specific cellular immunity components,such as the serum nitric oxide(NO),C3 and C4 levels,the specific cellular immunity components,such as the spleen index,peripheral blood IL-2,IFN-γ/IL-4,cytotoxic T(Tc)cell ratio,and splenic NF-κB mRNA levels,the humoral immunity components,such as the serum IgG level,the mucosal immunity components,such as the ileal MHC-II,CD3d,TCRβsubunit,TCRζsubunit,IFN-γ,pIgR mRNA and ileal mucosa sIgA levels,were continuing to increase from d 1 to 34.Conclusions:It could be concluded that the immune system and its function have not developed well in the broiler chickens d 6 to 13 and that the immune system does not mature until d 30 to 34 in the broiler chickens in cages.It is necessary to enhance the immune function of the broiler chickens through nutritional measures from d 1 to 30.

Dietary encapsulated essential oils and organic acids mixture improves gut health in broiler chickens challenged with necrotic enteritis

Background:The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE)due to Clostridium perfringens.In the present study,we investigated the effects of dietary supplementation with a blend of encapsulated essential oils and organic acids(BLJ)on growth performance and gut health using a coinfection model of NE in broiler chickens.Methods:Two hundred and eighty-eight one-day-old male Arbor Acres broiler chicks were randomly assigned using a 2×2 factorial design into two groups fed either 0 or 500 mg/kg dietary BLJ and co-challenged(or not challenged for the control)with Eimeria spp./C.perfringens.Results:Infected birds fed the BLJ-supplemented diet exhibited an improved feed conversion ratio throughout the trial(P<0.01),a higher villus height and villus height/crypt depth ratio,and reduced intestinal C.perfringens counts,liver C.perfringens carriage,gut lesion scores and serum fluorescein isothiocyanate dextran(FITC-D)concentrations at 7 d postinfection compared with those of birds without BLJ supplementation(P<0.05).NE-infected birds fed BLJ exhibited significantly upregulated claudin-1 and IGF-2 mRNA levels(P<0.05),increased A20 mRNA expression and significantly downregulated TRAF-6,TNFSF15 and TOLLIP mRNA levels in the jejunum at 7 d post-infection compared with those in birds without BLJ supplementation(P<0.05).Compared with the uninfected and untreated birds,the uninfected birds fed BLJ displayed increased relative abundances of Lactobacillus and Coprococcus but reduced Rikenellaceae levels.Compared with the unsupplemented NE-challenged birds,infected birds fed BLJ showed an increased relative abundance of Unclassified_Lachnospiraceae and a significantly decreased relative abundance of Erysipelotrichaceae.Conclusion:BLJ supplementation improved growth performance and gut health in NE-infected broiler chickens by strengthening the intestinal barrier function,positively modulating the gut microbiota community and differentially regulating intestinal immune responses.Our results also suggested that adding BLJ effectively controlled NE infections after experimental Eimeria and Clostridium perfringens coinfection.

Creatine Pyruvate Enhances Lipolysis and Protein Synthesis in Broiler Chicken

To assess the effects ofcreatine pyruvate （Cr-Pyr） on lipid and protein metabolism in broiler chickens, a total of 400 1-day-old male birds （Aconred） were randomly allocated to four groups, with each group replicating four times and each replicate involving 25 birds. The broilers were provided with a commercial diet supplemented with Cr-Pyr at 0, 1, 5, or 10% of the diet, respectively, for a period of 3 wk ad libitum （from 22 to 42 d）. In the present study, body weight （BW） and average daily gain （ADG） of broilers decreased in 10% Cr-Pyr group （P〈0.01）, whereas the relative leg and pectoral muscle weights were significantly higher than they were in the control group （P〈0.05）. 5 or 10% Cr-Pyr of diets decreased the abdominal fat rate （AFR, abdominal fat/live weight） of the broilers. The serum or hepatic triglyceride （TG） concentrations were significantly lower in the 5 and 10% groups （P〈0.01）. In contrast, Cr-Pyr caused a marked increase in the serum nonesterified fatty acid （NEFA）, high-density lipoprotein cholesterol （HDL-C） and creatine kinase （CK） concentrations （P〈0.01）. Supplementation with Cr-Pyr （5 and 10%） in the diet also increased glucagons （GLU）, insulin （INS） or leptin （LEP） contents （P〈0.01）. The expression of hepatic peroxisomal proliferators-activated receptor α （PPAR-α） and carnitine palmitoyl transferase-I （CPT-I）, muscle insulin-like growth factor I （IGF-I） were significantly elevated and myostatin mRNA level was reduced in the 5 and 10% groups （P〈0.05）. It was found that supplementation with 5% Cr-Pyr improves both lipid and protein metabolism by regulating various metabolic parameters of broilers, while not adversely affects growth performance in broiler chickens.

Molecular mechanisms of growth depression in broiler chickens(Gallus Gallus domesticus)mediated by immune stress:a hepatic proteome study

Background:Immunological stress decreases feed intake,suppresses growth and induces economic losses.However,the underlying molecular mechanism remains unclear.Label-free liquid chromatography and mass spectrometry(LC-MS)proteomics techniques were employed to investigate effects of immune stress on the hepatic proteome changes of Arbor Acres broilers(Gallus Gallus domesticus)challenged with Escherichia coli lipopolysaccharide(LPS).Results:Proteomic analysis indicated that 111 proteins were differentially expressed in the liver of broiler chickens from the immune stress group.Of these,28 proteins were down-regulated,and 83 proteins were up-regulated in the immune stress group.Enrichment analysis showed that immune stress upregulated the expression of hepatic proteins involved in defense function,amino acid catabolism,ion transport,wound healing,and hormone secretion.Furthermore,immune stress increased valine,leucine and isoleucine degradation pathways.Conclusion:The data suggests that growth depression of broiler chickens induced by immune stress is triggered by hepatic proteome alterations,and provides a new insight into the mechanism by which immune challenge impairs poultry production.