Background:The ban of in-feed antimicrobial additives has negatively affected the poultry industry by causing necrotic enteritis(NE)to emerge in the flocks.Alternatives such as Bacillus probiotics have shown to be eff...Background:The ban of in-feed antimicrobial additives has negatively affected the poultry industry by causing necrotic enteritis(NE)to emerge in the flocks.Alternatives such as Bacillus probiotics have shown to be effective on eliminating the negative effects of this disease.Two experiments were conducted to investigate the effect of Bacillus amyloliquefaciens CECT 5940(BA)in broiler chickens under NE challenge and/or fed diets with different protein levels.Methods:In both experiments,480 day-old mix-sexed Ross-308 broilers were arranged in a 2×2 factorial arrangement of treatments.In experiment 1,the factors were NE challenge(yes or no)and probiotic(yes or no).In experiment 2,the factors were dietary crude protein levels(standard or reduced)and probiotic(yes or no)and were used under NE challenge condition.Oral administration of Eimeria oocysts(day 9)followed by inoculation with Clostridium perfringens(day 14 and 15)was used to induce NE challenge.On day 16,two birds from each treatment were gavaged with fluorescein isothiocyanate-dextran(FITC-d)and blood samples were collected for gut integrity evaluation,and jejunal samples were collected for gene expression assay.Results:In experiment 1,BA supplementation decreased caspase-3(CASP3)(P<0.001)and caspase-8(CASP8)(P<0.05)and increased occludin(OCLD)(P<0.05)expression regardless of the challenge.Additionally,BA supplementation downregulated interfron-γ(IFN-γ)expression(P<0.01)and upregulated immunoglobulin-G(IgG)(P<0.01)and immunoglobulin-M(IgM)(P<0.05)only in challenged birds.In experiment 2,the expression of genes encoding mucin-2(MUC2)(P<0.001),tight junction protein-1(TJP1)(P<0.05)and OCLD(P<0.05)were upregulated by the addition of BA in the diet,regardless of the crude protein level.Further,BA supplementation downregulated INF-γ(P<0.01)and upregulated immunoglobulin-A(IgA)(P<0.05),IgM(P<0.05)and IgG(P<0.01)regardless of the crude protein level.Conclusion:These findings suggest that supplementation of BA in broiler diets can improve gut health by modulation of genes related to the mucosal barrier,tight junction,and immunity in broilers challenged by unfavourable conditions such as NE challenge.展开更多
Male and female broiler chickens differ in their growth performance,carcass part weights and nutrient requirements.The potential reasons for these differences have been explored by looking at differences in nutrient d...Male and female broiler chickens differ in their growth performance,carcass part weights and nutrient requirements.The potential reasons for these differences have been explored by looking at differences in nutrient digestibility,nutrient transporter gene expression as well as gut microbiota populations between male and female birds.Studies have shown that male broilers have higher crude protein requirements compared to female broilers.The expression of monosaccharide and amino acid transporters show conflicting results as expression depends on the interactions between sex and bird age and breed as well as which tissue is sampled.Differences in microbiota populations between the genders were reported which may contribute towards performance differences,however research in this area is limited.The differences observed between the sexes contribute to increased variation in nutrition trials,and the potential to rear birds as equally mixed-sex becomes an option to reduce the variation introduced by the sex effect.Difference in rearing options obviously would only be feasible provided a quick,practical and cost-effective method of sexing birds is available,a topic that is also discussed in this review.展开更多
It has been demonstrated that the fiber content of oilseed meals and total amino acids(AA)in distillers'grains products affects standardized ileal digestibility(SID)values from swine assays and that total protein ...It has been demonstrated that the fiber content of oilseed meals and total amino acids(AA)in distillers'grains products affects standardized ileal digestibility(SID)values from swine assays and that total protein concentration affects the AA digestibility in assays using chickens.This analysis was conducted to test the hypothesis that the total AA content of test samples affects the SID assay results.Databases containing total AA profiles and SID values of 20 feedstuffs commonly fed to pigs from 2 sources,AMINODat 5.0(Evonik Industries,2015)and the Nutrient Requirements of Swine,12th edition(NRC,2012)were used to compare AA concentration effects on standardized ileal digestibility coefficients.Databases were compared with AA and SID available in both data sets.The total AA values were similar for the 2 databases with an R2 of 0.979(P<0.001).The linear relationship between digestibility co-efficients from the 2 databases was highly significant,an R2 of 0.810(P<0.001).Both databases had increased SID values with increasing AA contents within and across feed ingredients.The SID=f(AA concentration)relationship was confirmed with an individual paper.Since SID,as typically measured,is a function of both digestion and absorption,both processes following MichaeliseMenten kinetics,SID=f(AA concentration)may simply be a natural phenomenon.Other reasons for the relationship were explored.Methods of estimating endogenous AA losses and misapplication statistical procedures may contribute to variation in results and at least partially explain why SID=f(AA concentration).展开更多
Structure of fibre has been reported to enhance performance,intestinal function and modify the composition and quantity of the microbial population in the chicken gastrointestinal tract.It is hypothesised that insolub...Structure of fibre has been reported to enhance performance,intestinal function and modify the composition and quantity of the microbial population in the chicken gastrointestinal tract.It is hypothesised that insoluble fibre in oat hulls may improve gut health and reduce intestinal Clostridium perfringens number.This research assessed the effect of free choice oat hulls(OH) on performance and gut microbiota in broilers during a mild(subclinical) necrotic enteritis(NE) challenge.A total of 240 dayold male Ross 308 broiler chickens were assigned to 24 cages in a 2×2 factorial arrangement of treatments.Factors were challenge - or +; and OH - or +.On d 16,challenged broilers had lower weight gain and feed intake(P < 0.05) compared with unchallenged broilers.Ond 16,broilers given OH had lower feed intake(P < 0.05) and tended to have lower(P=0.062) feed conversion ratio(FCR) compared with those without access to OH.Broiler performance,however,was not affected by OH nor by challenge on d 24 and 35.The broilers given OH had heavier gizzards(P < 0.05) compared with those without OH at d 35 but not at d 13 or 16.Increased numbers of C.perfringens(P < 0.001) and reduced numbers(P < 0.05)of Lactobacillus and Salmonellae were observed in the caecal contents of challenged broilers on d 16.Challenged broilers had a lower concentration of caecal acetic acid(P < 0.01) compared with unchallenged broilers at d 16.The broilers given OH had lower concentrations of caecal acetic acid(P < 0.05),propionic acid(P < 0.05),and valeric acid(P < 0.01) compared with those without access to OH.An OH by challenge interaction on succinic acid concentration was observed on d 16(P < 0.05).Oat hulls elevated the caecal succinic acid concentration only in the unchallenged broilers.This study indicated a positive role of OH through improved gizzard function and increased succinic acid in the gut but its role in controlling NE was not conclusive.展开更多
Subclinical necrotic enteritis(NE) causes devastating economic losses in the broiler chicken industry,especially in birds raised free of in-feed antibiotics. Prebiotics are potential alternatives to in-feed antibiotic...Subclinical necrotic enteritis(NE) causes devastating economic losses in the broiler chicken industry,especially in birds raised free of in-feed antibiotics. Prebiotics are potential alternatives to in-feed antibiotics. Yeast cell wall extract(YCW) derived from Saccharomyces cerevisiae is a prebiotic with known immune modulating effects. This study examined the effects of YCW and antibiotics(AB) during subclinical NE on broiler growth performance, intestinal lesions, humoral immune response and gut microflora metabolites. The study employed a 2 × 3 factorial arrangement of treatments. Factors were:NE challenge(yes or no) and feed additive(control, AB, or YCW). Each treatment was replicated in 8 floor pens with 15 birds per pen. Challenged birds had higher feed conversion ratio(FCR) than unchallenged birds on d 35(P < 0.05). Dietary inclusion of AB decreased FCR regardless of challenge(P < 0.05) on d 24 and 35. Inclusion of YCW reduced serum interleukin-1(IL-1) concentration in NE challenged birds(P < 0.01) and increased immunoglobulin(Ig) G(P < 0.05) and Ig M(P < 0.05) levels compared to other dietary treatments regardless of challenge. Yeast cell wall extract increased formic acid concentration in cecal contents during challenge and increased butyric acid concentration in unchallenged birds on d 16.This study indicates YCW suppressed inflammatory response, promoted generation of immunoglobulin and increased short chain fatty acid production suggesting potential benefits to bird health.展开更多
Arabinoxylo-oligosaccharides(AXOS) are hydrolytic degradation products of arabinoxylans(AX) that can be fermented by the gut microbiota, thus potentially displaying prebiotic properties. This study examined the effect...Arabinoxylo-oligosaccharides(AXOS) are hydrolytic degradation products of arabinoxylans(AX) that can be fermented by the gut microbiota, thus potentially displaying prebiotic properties. This study examined the effects of AX and AXOS on net energy(NE) and nutrient utilization in broilers. Ross 308 broilers(n = 90, 30 birds per treatment) were fed wheat-soybean diets supplemented with pure AX, AXOS produced by exposing the AX to xylanase in vitro(AXOS), or AX with xylanase(AX + E) from d 10 to 21.Performance parameters were measured from d 10 to 21. On d 15, 10 birds per treatment were allocated to closed-circuit net energy chambers to assess the impact of AX and AXOS on dietary energy utilization,through assessment of both metabolisable energy(ME) and NE. Ileal and caecal digesta samples were collected on d 21 to determine the effect of AX and AXOS on ileal and total tract dry matter digestibility,ileal digestible energy, digesta pH, short chain fatty acids(SCFA) and microbiota concentration. Feed conversion ratio was numerically the lowest in birds fed the diet supplemented with AXOS, which is 1.26 compared to 1.37 and 1.30 for AX and AX + E, respectively. Ileal dry matter digestibility was higher in birds fed AXOS than those fed AX(P = 0.047). Ileal digestible energy and total tract dry matter digestibility were higher in birds fed AXOS than those fed AX or AX + E(P = 0.004 and P = 0.001,respectively). Birds fed AXOS had higher ME intake(P = 0.049) and nitrogen retention(P = 0.001) and a strong trend of higher NE(P = 0.056), NE intake(P = 0.057) and retained energy(P = 0.054) compared to those fed AX. Ileal total SCFA, lactic and formic acid concentrations were higher in birds fed AXOS than those fed AX(P = 0.011, P = 0.012 and P = 0.023, respectively). Birds fed AXOS or AX + E had higher caecal total SCFA, acetic, butyric and isovaleric acid concentrations compared to those fed AX(P = 0.001,P = 0.004, P = 0.016 and P = 0.008, respectively), and caecal propionic acid concentration was higher in birds fed AX + E than those fed AX(P = 0.050). Ileal and caecal microbiota concentrations were numerically higher and pH was lower in birds fed AXOS and AX + E than those fed AX. Results from this study indicate that feeding AXOS directly is more efficient than AXOS generation in the gastrointestinal tract, and suggest that AXOS has a potential to be an efficacious prebiotic in broiler diets.展开更多
Organic acids(OA)and their blends have been shown to positively affect performance and health of broilers.However,the data in the literature are not consistent.This study examined the potential of blended short-chain ...Organic acids(OA)and their blends have been shown to positively affect performance and health of broilers.However,the data in the literature are not consistent.This study examined the potential of blended short-chain fatty acids(SCFA)with medium-chain fatty acids(MCFA)as alternatives to antibiotic growth promoters(AGP)on performance,health and welfare of broilers infected with necrotic enteritis(NE).The additives used were:A)a blend of SCFA,MCFA,and a phenolic compound(SMP);B)a blend of free and buffered SCFA with MCFA(SMF);C)a blend of free and buffered SCFA with a high concentration of MCFA(SHM).A total of 1,404 Ross 308 one-day-old male parental chicks were randomly distributed into 78-floor pens with 13 replicates of 18 birds each.Six treatments were the following:T1,unchal-lenged control(UCC);T2,challenged control(CHC);T3,challenged group plus zinc bacitracin(BAC);T4,challenged group plus additive SMP;T5,challenged group plus additive SMF;T6,challenged group plus additive SHM.Challenged birds were gavaged with Eimeria spp.on d 9 and Clostridium perfringens EHE-NE18 on d 14.Post NE challenge and cumulatively,BWG,FCR,and nutrient digestibility of birds were compromised(P<0.05)by NE challenge indicating a successful induction of sub-clinical NE.Additive SHM had higher BWG compared to CHC and BAC groups(P=0.001;d 10 to 24)but not different from SMP and SMF groups(P>0.05).All the 3 additive groups had lower FCR compared to CHC(P=0.001;d 0 to 35),and exhibited similar jejunal lesions(d 16)compared to BAC and apparent ileal protein di-gestibility(d 21)compared to UCC and BAC groups(P>0.05).Birds in additive SHM group had a higher concentration of serum IgA compared to all groups(P=0.001)except additive SMF(P>0.05;d 21).All the additive groups had lower footpad dermatitis and hock burns compared to CHC(P<0.05).The findings suggest the potential of blended OA as alternatives to BAC to protect broilers from NE indicated by improved FCR,immunity,digestibility,and bird welfare.展开更多
The effect of graded levels of phytase on performance, bone characteristics, excreta/litter quality and odorant emissions was examined using 720 Ross 308 male d-old broilers. A 2 x 4 factorial arrangement of treatment...The effect of graded levels of phytase on performance, bone characteristics, excreta/litter quality and odorant emissions was examined using 720 Ross 308 male d-old broilers. A 2 x 4 factorial arrangement of treatments was employed with 6 replicates of 15 birds per pen. Factors were: diets-positive and negative control(PC, NC); phytase-0, 500,1,000.1,500 FTU/kg. The PC was formulated to meet the 2014 Ross 308 nutrient specifications, whereas the NC was formulated with lower Ca(-1.4 g/kg), available P(-1.5 g/kg), Na(-0.3 g/kg), dLys(-0.2 g/kg) and MEn(-0.28 MJ/kg) equivalent to nutrient matrix values for 500 FTU/kg phytase in the starter,grower and finisher periods(i.e.,downspec diet). On d 24, phytase decreased FCR by 1.6, 4.3 and 4.6 points at inclusion levels of 500.1,000 and 1,500 FTU/kg, respectively(P < 0.01) across all diets. Phytase by diet interactions on BW gain were observed on d 24 and 35(P < 0.01). The effect of phytase was much more pronounced in the NC diet as compared with the PC diet.On d 24, phytase increased BW gain by 37, 55 and 68 g in the PC and 127.233 and 173 g in the NC at 500,1,000 and 1,500 FTU/kg, respectively. Diet by phytase interactions were also observed for tibia ash, litter quality and water to feed intake ratio(P < 0.01) with higher phytase effect in NC as compared with PC.Neither diet nor phytase impacted excreta moisture content on d 18 or 21(P> 0.05). Solid phase microextraction gas chromatography-mass spectrometry(SPME-GC-MS) analysis of gaseous emissions on d 39 indicated no difference in the emission of alcohols, aldehydes, ketones, volatile fatty acids and phenols between treatments(P> 0.05). The results indicate that phytase has greater benefits when formulated using nutrient matrix values as compared with adding it over the top in an already nutrient sufficient diet. The later method would be expected to increase feed costs without concomitant performance benefits.展开更多
Two studies were conducted to investigate the effect of Bacillus amyloliquefaciens CECr 5940(BA)as a probiotic on growth performance,amino acid digestibility and bacteria population in broiler chickens under a subclin...Two studies were conducted to investigate the effect of Bacillus amyloliquefaciens CECr 5940(BA)as a probiotic on growth performance,amino acid digestibility and bacteria population in broiler chickens under a subclinical necrotic enteritis(NE)challenge and/or fed diets with different levels of crude protein(CP).Both studies consisted of a 2×2 factorial arrangement of treatments with 480 Ross 308 mix-sexed broiler chickens.In study 1,treatments included 1)NE challenge(+/),and 2)BA(1.0×106 CFU/g of feed)supplementation(+/-).In study 2,all birds were under NE challenge,and treatments were 1)CP level(Standard/Reduced[2%less than standard])and 2)BA(1.0×106 CFU/g of feed)supplementation(+/-).After inducing NE infection,blood samples were taken on d 16 for uric acid evaluation,and cecal samples were collected for bacterial enumeration.In both studies,ileal digesta was collected on d 35 for nutrient digestibility evaluation.In study 1,the NE challenge reduced body weight gain(BWG),supressed feed conversion ratio(FCR)and serum uric acid levels(P<0.001).Supplementation of BA increased BWG(P<0.001)and reduced FCR(P=0.043)across dietary treatments,regardless of challenge.Bacillus(P=0.030)and Ruminococcus(P=0.029)genomic DNA copy numbers and concentration of butyrate(P=0.017)were higher in birds fed the diets supplemented with BA.In study 2,reduced protein(RCP)diets decreased BWG(P=0.010)and uric acid levels in serum(P<0.001).Supplementation of BA improved BWG(P=0.001)and FCR(P=0.005)and increased Ruminococcus numbers(P=0.018)and butyrate concentration(P=0.033)in the ceca,regardless of dietary CP level.Further,addition of BA reduced Clostridium perfringens numbers only in birds fed with RCP diets(P=0.039).At d 35,BA sup-plemented diets showed higher apparent ileal digestibility of cystine(P=0.013),valine(P=0.020),and lysine(P=0.014).In conclusion,this study suggests positive effects of BA supplementation in broiler diets via modulating gut microflora and improving nutrient uptake.展开更多
Abatement of odour emissions has become an important consideration to agricultural industries,including poultry production. The link between diet and odour emissions was studied in two experiments using Ross 308 male ...Abatement of odour emissions has become an important consideration to agricultural industries,including poultry production. The link between diet and odour emissions was studied in two experiments using Ross 308 male meat chickens reared in specially designed chambers in a climate controlled room. In the first experiment, two treatments were compared using three replicates of two birds per chamber. Two wheat-soy based treatment diets were formulated with or without canola seed, an ingredient rich in sulfur amino acids, Treatment 1(T1) had 13,39 MJ/kg ME(as fed) and used 60 g/kg canola seed without corn while Treatment 2(T2) contained 12.90 MJ/kg ME(as fed) and used 150 g/kg corn without canola seed. In the second experiment, birds were assigned to three dietary treatments of five replicates with five birds per replicate(chamber). The basal starter, grower and finisher diets in the control group(SBM group) contained soybean meal in the range of 227-291 g/kg(as fed) as the main protein source. The other treatments(CM and MBM groups) contained either high levels of canola meal(174-190 g/kg) or meat meal(74-110 g/kg) at the expense of soybean meal. In both experiments, diets were isocaloric, isonitrogenous and contained similar digestible amino acid contents as per 2007 Aviagen Ross 308 guidelines. Emissions of odour were measured using Fourier transform infrared(FTIR) spectroscopy. In both experiments, major odorous compounds detected included 2,3-butanedione(diacetyl),2-butanone, dimethyl disulfide, methyl mercaptan, ethyl mercaptan, 2-butanol, 3-methyl-butanal,phenol and m-cresol. In the first experiment, Tl(with canola seed) produced higher concentration of methyl mercaptan(P < 0.05) and lower diacetyl(P < 0.01) than T2. In the second experiment, methyl mercaptan emission was higher in SBM group(P = 0.01) and total elemental sulfur were higher in SBM and CM groups up to day 24(P < 0.01). Results of these experiments indicated a direct link between diet and odour emissions from meat chickens.展开更多
The cost of feed represents an important part of the total cost in swine and poultry production(>60%)with energy accounting for at least 70%of feed cost.The energy value of ingredients or compound feeds can be esti...The cost of feed represents an important part of the total cost in swine and poultry production(>60%)with energy accounting for at least 70%of feed cost.The energy value of ingredients or compound feeds can be estimated as digestible(DE),metabolisable(ME)and net energy(NE)in pigs and ME and NE in poultry.The current paper reviews the different methods for evaluating DE,ME and NE of feeds for monogastric animals and their difficulties and limits,with a focus on NE.In pigs and poultry,energy digestibility depends on the chemical characteristics of the feed,but also on technology(pelleting,for instance)and animal factors such as their health and body weight.The ME value includes the energy losses in urine that are directly dependent on the proportion of dietary N excreted in urine resulting in the concept of ME adjusted for a zero N balance(MEn)in poultry.For poultry,the concept of true ME(TME,TMEn),which excludes the endogenous fecal and urinary energy losses from the excreta energy,was also developed.The measurement of dietary NE is more complex,and NE values of a given feed depend on the animal and environmental factors and also measurement and calculation methods.The combination of NE values of diets obtained under standardised conditions allows calculating NE prediction equations that are applicable to both ingredients and compound feeds.The abundance of energy concepts,especially for poultry,and the numerous feed and animal factors of variation related to energy digestibility or ME utilisation for NE suggest that attention must be paid to the experimental conditions for evaluating DE,ME or NE content.This also suggests the necessity of standardisations,one of them being,as implemented in pigs,an adjustment of ME values in poultry for an N retention representative of modern production conditions(MEs).In conclusion,this review illustrates that,in addition to numerous technical difficulties for evaluating energy in pigs and poultry,the absolute energy values depend on feed and animal factors,the environment,and the methods and concepts.Finally,as implemented in pigs,the use of NE values should be the objective of a more reliable energy system for poultry feeds.展开更多
Pea starch consists predominantly of C-type of amylopectin chain which is more resistant to digestive enzymes than A-type of starch thus slowly digested in poultry.It was hypothesized that the presence of slowly diges...Pea starch consists predominantly of C-type of amylopectin chain which is more resistant to digestive enzymes than A-type of starch thus slowly digested in poultry.It was hypothesized that the presence of slowly digested pea starch in broiler diets will increase net energy and the efficiency of energy utilization in broilers.Two experiments were performed to investigate starch digestibility of pea at different in-cubation times(in vitro study)and the effect of dietary pea on heat increment and net energy in broilers using an open-circuit respiratory calorimetry system(in vivo study).One-day-old Ross 308 male broilers were fed a common starter crumble from d 1 to 10 and standard grower diets thereafter.At d 21,birds were transferred to the chambers each housing 2 birds.Each treatment was replicated 6 times with 2 identical runs of 3 replicates per treatment.A wheat-soybean meal-based diet was used as a control and the treatment diet contained 500 g of pea/kg pea.In vitro study showed that pellet processing increased(P<0.001)starch digestibility,particularly at shorter times for wheat and a much larger response for pea.Birds offered the pea-based diet had lower(P=0.002)feed intake,lower(P=0.020)body weight gain,but a similar(P>0.05)FCR compared to those offered the wheat-based diet.Net energy(NE)and apparent metabolizable energy(AME)values were higher in the pea-based diet than in the wheat-based diet(P-0.037 for NE and P-0.018 for AME).Heat production,respiratory quotient,heat increment of feed,efficiency of utilization of gross energy for AME,and efficiency of utilization of AME for NE did not differ(P>0.05)between the 2 treatments.There was no effect(P>0.05)of pea on the total tract di-gestibilities of dry matter,crude protein and ash,but the total tract digestibility of starch was higher(P-0.022)in the pea-based diet compared to the wheat-based diet.This study provides insight into the energy metabolism of broilers offered a pea-based diet and indicates that dietary pea supplementation increases dietary AME and NE but has no effect on heat increment of feed and the efficiency of energy utilization in broilers.展开更多
Controlling enteric diseases of broilers is crucial.Among many additives,organic acids(OA)and their blends are gaining attention to combat diseases in the post-antibiotic era.The current study evaluated the potentials...Controlling enteric diseases of broilers is crucial.Among many additives,organic acids(OA)and their blends are gaining attention to combat diseases in the post-antibiotic era.The current study evaluated the potentials of short-chain fatty acids(SCFA)and medium-chain fatty acids(MCFA)blends and/or phenolic compounds on intestinal integrity,intestinal pH,caecal microbiota,and caecal SCFA profiles of broilers under necrotic enteritis(NE)challenge.The additives used were:(A)a blend of SCFA,MCFA,and a phenolic compound(SMP),(B)a blend of free and buffered SCFA with MCFA(SMF),and(C)a blend of free and buffered SCFA with a high concentration of MCFA(SHM).A total of 1,404 male parental chicks of Ross 308 broilers were randomly allocated to 78 floor pens on hatching day with 6 treatments replicated 13 times with 18 birds per pen.The treatments were:UCC,unchallenged control;CHC,challenged control;BAC,challenged group plus zinc bacitracin;SMP,challenged group plus additive SMP;SMF,challenged group plus additive SMF;SHM,challenged group plus additive SHM.Birds were challenged with field-strain Eimeria spp.on d 9 and Clostridium perfringens on d 14.Birds challenged with NE increased fluorescein isothiocyanate dextran(FITC-d)concentration in serum,reduced acetate and butyrate concentrations,and increased Bacteroides and C.perfringens load in the caeca(P<0.05).Birds fed additives decreased FITC-d from gut to serum,reduced Bacteroides(d 16,P<0.05)and numerically reduced C.perfringens load compared to CHC group.Birds fed additive SHM had higher concentrations of acetate and butyrate(d 21,P<0.05)than CHC group but were not different from SMP and SMF groups.All the additives exhibited similar intestinal protection against NE compared to the BAC group indicated by FITC-d concentration in serum,acetate,propionate and butyrate concentrations in the caeca,and caecal bacterial loads except for the C.perfringens(P>0.05).The SMP group had a higher load compared to BAC(P<0.05).These findings suggest the promising effects of OA blends as alternatives to BAC to ameliorate the impact of NE challenge of broilers as indicated by improved intestinal health.展开更多
Plant extracts(PE)are gaining increased attention as potential alternatives to in-feed antimicrobials(AM)due to their known antimicrobial activities.This study was conducted to examine the potential of PE,a microencap...Plant extracts(PE)are gaining increased attention as potential alternatives to in-feed antimicrobials(AM)due to their known antimicrobial activities.This study was conducted to examine the potential of PE,a microencapsulated product composed of eugenol and garlic tincture as an alternative to AM-agent on performance and intestinal health in broilers under necrotic enteritis(NE)challenge.A total of 960 dayold mixed-sex Cobb 500 chicks were randomly distributed to 48-floor pens with 6 treatments replicated 8 times with 20 birds each.The 6 treatments were as follows:UC,unchallenged control;CC,challenged control;PE,challenged group plus PE;AM,challenged group plus AM;FAP,challenged group plus a full dose of AM with PE;HAP,challenged group plus a half dose of AM with PE in starter,grower and finisher phases.Birds in the challenged groups were inoculated with Eimeria spp.on d 9 and Clostridium perfringens on d 14.The body weight gain(BWG),feed intake(FI),feed conversion ratio(FCR),and livability of birds were compromised,and intestinal lesions and mortality were increased(P<0.05)by NE challenge,illustrating a successful clinical NE challenge.Birds fed AM had higher BWG and FI,and lower FCR,mortality,and intestinal lesions compared to the CC group(P<0.05).Birds fed PE had improved FCR(P<0.05)and livability(5.8%)in an overall period compared to the CC group.On d 16,PE supplementation reduced ileal lesion scores in only male birds(P<0.05).Birds fed PE had decreased Eimeria maxima and Eimeria acervulina oocyst counts in caecal content(P<0.05).Birds fed PE had decreased Eimeria brunetti and total oocyst counts in caecal content,and E.acervulina oocyst counts in ileal content in only female birds(P<0.05).On d 35,PE supplementation reduced variation of BW in both male and female birds and increased yellowness(b*value,14.4%)in the thigh.These findings suggest the potential of PE supplementation in diets to improve the performance and intestinal health of birds under clinical NE as indicated by improved FCR,livability,uniformity,reduced ileal lesions,oocyst counts and increased skin yellowness.However,the protective effect of PE may not be apparent in the presence of AM in the feed.展开更多
Subclinical necrotic enteritis(NE) is an economically important disease in the broiler industry. With the move towards removal of antibiotics from feeds, solutions to control subclinical NE are desperately being sough...Subclinical necrotic enteritis(NE) is an economically important disease in the broiler industry. With the move towards removal of antibiotics from feeds, solutions to control subclinical NE are desperately being sought. Dietary glycine has been shown to promote proliferation of Clostridium perfringens(Cp) and may thus be useful to include in a NE challenge model. A study was conducted to evaluate the effect of increased dietary glycine levels on subclinical NE. A 2 × 2 × 2 factorial arrangement of treatments was carried out using day-old male Ross 308 chicks(n = 624) allocated to 48 floor pens with 8 treatments of 6 replicates with 11 birds per treatment. Factors were: Cp challenge(C-or C+), Eimeria spp. challenge(Eor E+), and dietary glycine in the grower diet(0 or 10 g/kg). Birds had higher FCR when challenged with Eimeria(P < 0.01) or Cp(P < 0.05) on d 24 or Cp on d 35 but FCR was lower when fed glycine on d 24(P < 0.01). Supplementation of glycine reduced feed intake on d 24 and increased weight gain on d 35(P < 0.05). A Cp × Eimeria × glycine interaction(P < 0.05) showed a higher jejunal lesion scores in birds challenged with a combination of Cp and glycine compared with those with Eimeria and glycine or the unchallenged birds. Lesion score interactions between Cp and glycine(P < 0.05) in the ileum and Cp and Eimeria in the duodenum(P < 0.05) and ileum(P < 0.05) illustrated higher lesion scores in birds challenged with Cp without Eimeria or glycine compared to those not challenged with Cp. This study suggests that using glycine can partially replace Eimeria in a subclinical NE challenge model in promoting the intestinal lesions but not impairing chicken performance.展开更多
Broilers that have early access to feed have been shown to have enhanced immune system and gut development and heightened resilience against necrotic enteritis(NE). This study examined the effect of early feeding a hi...Broilers that have early access to feed have been shown to have enhanced immune system and gut development and heightened resilience against necrotic enteritis(NE). This study examined the effect of early feeding a high amino acid density diet on performance of broilers under a sub-clinical NE challenge model. Ross 308 broilers(n = 576) were assigned to a 2 × 2 × 2 factorial design with 2 feeding regimes(feed access either within 6 h post-hatch or after 48 h post-hatch), 2 diets(control diet or the control diet with an additional 10% digestible amino acids [HAA]) and either presence or absence of NE challenge.Oral administrations of Eimeria species(d 9) and a field strain of Clostridium perfringens(d 14) were used to induce NE, Broiler performance was analysed at d 13.23.30 and 35, Intestinal lesion score and bacterial count were analysed on d 16. The NE challenge reduced overall bird performance and induced severe intestinal lesions, without causing notable mortality. At d 23 bird weight was significantly lower(P < 0.001) in the challenged birds compared with the unchallenged birds, but by d 30 the challenged birds had recovered and challenge no longer had an impact on bird performance. Birds fed the HAA diet had greater body weight by d 35 and heightened Lactobacillus content in the ileum at d 16(P < 0.05).Birds that were fed the HAA diet after a period of fasting performed better in terms of feed conversion ratio(FCR) under challenge. The findings from this study suggest there are beneficial effects of feeding high amino acid diets to birds in response to external stresses, such as post-hatch fasting and subclinical NE.展开更多
Necrotic enteritis(NE)is an important enteric disease in poultry and has become a major concern in poultry production in the post-antibiotic era.The infection with NE can damage the intestinal mucosa of the birds lead...Necrotic enteritis(NE)is an important enteric disease in poultry and has become a major concern in poultry production in the post-antibiotic era.The infection with NE can damage the intestinal mucosa of the birds leading to impaired health and,thus,productivity.To gain a better understanding of how NE impacts the gut function of infected broilers,global mRNA sequencing(RNA-seq)was performed in the jejunum tissue of NE challenged and non-challenged broilers to identify the pathways and genes affected by this disease.Briefly,to induce NE,birds in the challenge group were inoculated with 1 mL of Eimeria species on day 9 followed by 1 mL of approximately 108 CFU/mL of a NetB producing Clostridium per-fringens on days 14 and 15.On day 16,2 birds in each treatment were randomly selected and euthanized and the whole intestinal tract was evaluated for lesion scores.Duodenum tissue samples from one of the euthanized birds of each replicate(n=4)was used for histology,and the jejunum tissue for RNA extraction.RNA-seq analysis was performed with an Illumina RNA HiSeq 2000 sequencer.The differ-entially expressed genes(DEG)were identified and functional analysis was performed in DAVID to find protein-protein interactions(PPI).At a false discovery rate threshold<0.05,a total of 377 DEG(207 upregulated and 170 downregulated)DEG were identified.Pathway enrichment analysis revealed that DEG were considerably enriched in peroxisome proliferator-activated receptors(PPAR)signaling(P<0.01)andβ-oxidation pathways(P<0.05).The DEG were mostly related to fatty acid metabolism and degradation(cluster of differentiation 36[CD36],acyl-CoA synthetase bubblegum family member-1[ACSBG1],fatty acid-binding protein-1 and-2[FABP1]and[FABP2];and acyl-coenzyme A synthetase-1[ACSL1]),bile acid production and transportation(acyl-CoA oxidase-2[ACOX2],apical sodium-bile acid transporter[ASBT])and essential genes in the immune system(interferon-,[IFN-γ],LCK proto-oncogene,Src family tyrosine kinase[LCK],zeta chain of T cell receptor associated protein kinase 70 kDa[ZAP70],and aconitate decarboxylase 1[ACOD1]).Our data revealed that pathways related to fatty acid digestion were significantly compromised which thereby could have affected metabolic and immune responses in NE infected birds.展开更多
Artificial gut models including both the gastric and intestinal phases have been used in poultry research for decades to predict the digestibility of nutrients,the efficacy of feed enzymes and additives,and caecal fer...Artificial gut models including both the gastric and intestinal phases have been used in poultry research for decades to predict the digestibility of nutrients,the efficacy of feed enzymes and additives,and caecal fermentation.However,the models used in the past are static and cannot be used to predict interactions between the feed,gut environment and microbiome.It is imperative that a standard artificial gut model for poultry is established,to enable these interactions to be examined without continual reliance on animals.To ensure the validity of an artificial model,it should be validated with in vivo studies.This review describes current practices in the use of artificial guts in research,their importance in poultry nutrition studies and highlights an opportunity to develop a dynamic gut model for poultry to reduce the number of in vivo experiments.展开更多
This study evaluated the effect of multi-carbohydrase(MC)on energy and nitrogen(N)balance and gene expression in broilers fed diets with different crude protein(CP)contents.The study employed a 2×2 factorial arra...This study evaluated the effect of multi-carbohydrase(MC)on energy and nitrogen(N)balance and gene expression in broilers fed diets with different crude protein(CP)contents.The study employed a 2×2 factorial arrangement of treatments.The factors were presence or absence of MC,and standard(SCP)or low(LCP)dietary CP concentration.A 3-phase feeding program was used,including starter(0 to 7 d),grower(8 to 17 d)and finisher(18 to 28 d)phases.The study was undertaken in closed calorimetry chambers.Each of the 4 dietary treatments was replicated 8 times in total across 2 runs,with 2 birds per replicate(n=64).Data for energy partitioning and N balance were collected from d 25 to 28.On d 28,birds were euthanized to collect muscle and intestinal tissue samples for gene expression.The results showed that the MC increased apparent metabolizable energy(AME,P<0.01)and net energy(NE,P<0.05),and reduced the feed conversion ratio(FCR,P<0.01)in all diets.The proportion of energy retained as fat per total energy retention(REf/RE)was positively correlated with feed AME and NE(r=0.541,P<0.01 and r=0.665,P<0.001,respectively),suggesting that feed energy augmented with increased fat gain.Muscle ATP synthase subunit alpha(ATPSA1W)gene expression had a positive cor-relation with REf/RE and feed NE(r=0.587,P<0.001 and r=0.430,P<0.05,respectively).Similarly,muscle peroxisome proliferator-activated receptor gamma coactivator 1 alpha(PGC-1A)expression was negatively correlated with weight gain and positively correlated with FCR(r-0.451,P<0.05 and r-0.359,P<0.05,respectively).These correlations show that over-expressions of muscle genes related to energy production reduce bird performance.This study demonstrated that MC increase dietary energy utilization,regardless of dietary CP concentration.However,the energy released by the enzymes in-creases feed energy-to-CP ratio,meaning there is excess energy that is then deposited as body fat.This suggests that supplemental MC in broiler feeds is beneficial if diets are formulated to contain marginal energy levels.展开更多
基金supported by grants of Evonik Nutrition&Care GmbH,Germany.
文摘Background:The ban of in-feed antimicrobial additives has negatively affected the poultry industry by causing necrotic enteritis(NE)to emerge in the flocks.Alternatives such as Bacillus probiotics have shown to be effective on eliminating the negative effects of this disease.Two experiments were conducted to investigate the effect of Bacillus amyloliquefaciens CECT 5940(BA)in broiler chickens under NE challenge and/or fed diets with different protein levels.Methods:In both experiments,480 day-old mix-sexed Ross-308 broilers were arranged in a 2×2 factorial arrangement of treatments.In experiment 1,the factors were NE challenge(yes or no)and probiotic(yes or no).In experiment 2,the factors were dietary crude protein levels(standard or reduced)and probiotic(yes or no)and were used under NE challenge condition.Oral administration of Eimeria oocysts(day 9)followed by inoculation with Clostridium perfringens(day 14 and 15)was used to induce NE challenge.On day 16,two birds from each treatment were gavaged with fluorescein isothiocyanate-dextran(FITC-d)and blood samples were collected for gut integrity evaluation,and jejunal samples were collected for gene expression assay.Results:In experiment 1,BA supplementation decreased caspase-3(CASP3)(P<0.001)and caspase-8(CASP8)(P<0.05)and increased occludin(OCLD)(P<0.05)expression regardless of the challenge.Additionally,BA supplementation downregulated interfron-γ(IFN-γ)expression(P<0.01)and upregulated immunoglobulin-G(IgG)(P<0.01)and immunoglobulin-M(IgM)(P<0.05)only in challenged birds.In experiment 2,the expression of genes encoding mucin-2(MUC2)(P<0.001),tight junction protein-1(TJP1)(P<0.05)and OCLD(P<0.05)were upregulated by the addition of BA in the diet,regardless of the crude protein level.Further,BA supplementation downregulated INF-γ(P<0.01)and upregulated immunoglobulin-A(IgA)(P<0.05),IgM(P<0.05)and IgG(P<0.01)regardless of the crude protein level.Conclusion:These findings suggest that supplementation of BA in broiler diets can improve gut health by modulation of genes related to the mucosal barrier,tight junction,and immunity in broilers challenged by unfavourable conditions such as NE challenge.
基金Sustainable Commercial Egg Production Scholarship of The University of New England (UNE) for funding Ashley England.
文摘Male and female broiler chickens differ in their growth performance,carcass part weights and nutrient requirements.The potential reasons for these differences have been explored by looking at differences in nutrient digestibility,nutrient transporter gene expression as well as gut microbiota populations between male and female birds.Studies have shown that male broilers have higher crude protein requirements compared to female broilers.The expression of monosaccharide and amino acid transporters show conflicting results as expression depends on the interactions between sex and bird age and breed as well as which tissue is sampled.Differences in microbiota populations between the genders were reported which may contribute towards performance differences,however research in this area is limited.The differences observed between the sexes contribute to increased variation in nutrition trials,and the potential to rear birds as equally mixed-sex becomes an option to reduce the variation introduced by the sex effect.Difference in rearing options obviously would only be feasible provided a quick,practical and cost-effective method of sexing birds is available,a topic that is also discussed in this review.
文摘It has been demonstrated that the fiber content of oilseed meals and total amino acids(AA)in distillers'grains products affects standardized ileal digestibility(SID)values from swine assays and that total protein concentration affects the AA digestibility in assays using chickens.This analysis was conducted to test the hypothesis that the total AA content of test samples affects the SID assay results.Databases containing total AA profiles and SID values of 20 feedstuffs commonly fed to pigs from 2 sources,AMINODat 5.0(Evonik Industries,2015)and the Nutrient Requirements of Swine,12th edition(NRC,2012)were used to compare AA concentration effects on standardized ileal digestibility coefficients.Databases were compared with AA and SID available in both data sets.The total AA values were similar for the 2 databases with an R2 of 0.979(P<0.001).The linear relationship between digestibility co-efficients from the 2 databases was highly significant,an R2 of 0.810(P<0.001).Both databases had increased SID values with increasing AA contents within and across feed ingredients.The SID=f(AA concentration)relationship was confirmed with an individual paper.Since SID,as typically measured,is a function of both digestion and absorption,both processes following MichaeliseMenten kinetics,SID=f(AA concentration)may simply be a natural phenomenon.Other reasons for the relationship were explored.Methods of estimating endogenous AA losses and misapplication statistical procedures may contribute to variation in results and at least partially explain why SID=f(AA concentration).
基金The Higher Committee for Education Development in Iraq (HCED) provided the principal author a scholarship
文摘Structure of fibre has been reported to enhance performance,intestinal function and modify the composition and quantity of the microbial population in the chicken gastrointestinal tract.It is hypothesised that insoluble fibre in oat hulls may improve gut health and reduce intestinal Clostridium perfringens number.This research assessed the effect of free choice oat hulls(OH) on performance and gut microbiota in broilers during a mild(subclinical) necrotic enteritis(NE) challenge.A total of 240 dayold male Ross 308 broiler chickens were assigned to 24 cages in a 2×2 factorial arrangement of treatments.Factors were challenge - or +; and OH - or +.On d 16,challenged broilers had lower weight gain and feed intake(P < 0.05) compared with unchallenged broilers.Ond 16,broilers given OH had lower feed intake(P < 0.05) and tended to have lower(P=0.062) feed conversion ratio(FCR) compared with those without access to OH.Broiler performance,however,was not affected by OH nor by challenge on d 24 and 35.The broilers given OH had heavier gizzards(P < 0.05) compared with those without OH at d 35 but not at d 13 or 16.Increased numbers of C.perfringens(P < 0.001) and reduced numbers(P < 0.05)of Lactobacillus and Salmonellae were observed in the caecal contents of challenged broilers on d 16.Challenged broilers had a lower concentration of caecal acetic acid(P < 0.01) compared with unchallenged broilers at d 16.The broilers given OH had lower concentrations of caecal acetic acid(P < 0.05),propionic acid(P < 0.05),and valeric acid(P < 0.01) compared with those without access to OH.An OH by challenge interaction on succinic acid concentration was observed on d 16(P < 0.05).Oat hulls elevated the caecal succinic acid concentration only in the unchallenged broilers.This study indicated a positive role of OH through improved gizzard function and increased succinic acid in the gut but its role in controlling NE was not conclusive.
基金Alltech (USA) is gratefully acknowledged for funding this project(13-E-9150)
文摘Subclinical necrotic enteritis(NE) causes devastating economic losses in the broiler chicken industry,especially in birds raised free of in-feed antibiotics. Prebiotics are potential alternatives to in-feed antibiotics. Yeast cell wall extract(YCW) derived from Saccharomyces cerevisiae is a prebiotic with known immune modulating effects. This study examined the effects of YCW and antibiotics(AB) during subclinical NE on broiler growth performance, intestinal lesions, humoral immune response and gut microflora metabolites. The study employed a 2 × 3 factorial arrangement of treatments. Factors were:NE challenge(yes or no) and feed additive(control, AB, or YCW). Each treatment was replicated in 8 floor pens with 15 birds per pen. Challenged birds had higher feed conversion ratio(FCR) than unchallenged birds on d 35(P < 0.05). Dietary inclusion of AB decreased FCR regardless of challenge(P < 0.05) on d 24 and 35. Inclusion of YCW reduced serum interleukin-1(IL-1) concentration in NE challenged birds(P < 0.01) and increased immunoglobulin(Ig) G(P < 0.05) and Ig M(P < 0.05) levels compared to other dietary treatments regardless of challenge. Yeast cell wall extract increased formic acid concentration in cecal contents during challenge and increased butyric acid concentration in unchallenged birds on d 16.This study indicates YCW suppressed inflammatory response, promoted generation of immunoglobulin and increased short chain fatty acid production suggesting potential benefits to bird health.
文摘Arabinoxylo-oligosaccharides(AXOS) are hydrolytic degradation products of arabinoxylans(AX) that can be fermented by the gut microbiota, thus potentially displaying prebiotic properties. This study examined the effects of AX and AXOS on net energy(NE) and nutrient utilization in broilers. Ross 308 broilers(n = 90, 30 birds per treatment) were fed wheat-soybean diets supplemented with pure AX, AXOS produced by exposing the AX to xylanase in vitro(AXOS), or AX with xylanase(AX + E) from d 10 to 21.Performance parameters were measured from d 10 to 21. On d 15, 10 birds per treatment were allocated to closed-circuit net energy chambers to assess the impact of AX and AXOS on dietary energy utilization,through assessment of both metabolisable energy(ME) and NE. Ileal and caecal digesta samples were collected on d 21 to determine the effect of AX and AXOS on ileal and total tract dry matter digestibility,ileal digestible energy, digesta pH, short chain fatty acids(SCFA) and microbiota concentration. Feed conversion ratio was numerically the lowest in birds fed the diet supplemented with AXOS, which is 1.26 compared to 1.37 and 1.30 for AX and AX + E, respectively. Ileal dry matter digestibility was higher in birds fed AXOS than those fed AX(P = 0.047). Ileal digestible energy and total tract dry matter digestibility were higher in birds fed AXOS than those fed AX or AX + E(P = 0.004 and P = 0.001,respectively). Birds fed AXOS had higher ME intake(P = 0.049) and nitrogen retention(P = 0.001) and a strong trend of higher NE(P = 0.056), NE intake(P = 0.057) and retained energy(P = 0.054) compared to those fed AX. Ileal total SCFA, lactic and formic acid concentrations were higher in birds fed AXOS than those fed AX(P = 0.011, P = 0.012 and P = 0.023, respectively). Birds fed AXOS or AX + E had higher caecal total SCFA, acetic, butyric and isovaleric acid concentrations compared to those fed AX(P = 0.001,P = 0.004, P = 0.016 and P = 0.008, respectively), and caecal propionic acid concentration was higher in birds fed AX + E than those fed AX(P = 0.050). Ileal and caecal microbiota concentrations were numerically higher and pH was lower in birds fed AXOS and AX + E than those fed AX. Results from this study indicate that feeding AXOS directly is more efficient than AXOS generation in the gastrointestinal tract, and suggest that AXOS has a potential to be an efficacious prebiotic in broiler diets.
基金This study was financially supported by Trouw Nutrition,a Nutreco company,The Netherlands.
文摘Organic acids(OA)and their blends have been shown to positively affect performance and health of broilers.However,the data in the literature are not consistent.This study examined the potential of blended short-chain fatty acids(SCFA)with medium-chain fatty acids(MCFA)as alternatives to antibiotic growth promoters(AGP)on performance,health and welfare of broilers infected with necrotic enteritis(NE).The additives used were:A)a blend of SCFA,MCFA,and a phenolic compound(SMP);B)a blend of free and buffered SCFA with MCFA(SMF);C)a blend of free and buffered SCFA with a high concentration of MCFA(SHM).A total of 1,404 Ross 308 one-day-old male parental chicks were randomly distributed into 78-floor pens with 13 replicates of 18 birds each.Six treatments were the following:T1,unchal-lenged control(UCC);T2,challenged control(CHC);T3,challenged group plus zinc bacitracin(BAC);T4,challenged group plus additive SMP;T5,challenged group plus additive SMF;T6,challenged group plus additive SHM.Challenged birds were gavaged with Eimeria spp.on d 9 and Clostridium perfringens EHE-NE18 on d 14.Post NE challenge and cumulatively,BWG,FCR,and nutrient digestibility of birds were compromised(P<0.05)by NE challenge indicating a successful induction of sub-clinical NE.Additive SHM had higher BWG compared to CHC and BAC groups(P=0.001;d 10 to 24)but not different from SMP and SMF groups(P>0.05).All the 3 additive groups had lower FCR compared to CHC(P=0.001;d 0 to 35),and exhibited similar jejunal lesions(d 16)compared to BAC and apparent ileal protein di-gestibility(d 21)compared to UCC and BAC groups(P>0.05).Birds in additive SHM group had a higher concentration of serum IgA compared to all groups(P=0.001)except additive SMF(P>0.05;d 21).All the additive groups had lower footpad dermatitis and hock burns compared to CHC(P<0.05).The findings suggest the potential of blended OA as alternatives to BAC to protect broilers from NE indicated by improved FCR,immunity,digestibility,and bird welfare.
基金supported under the Australian Government's Cooperative Research Centres Programa part of Poultry CRC sub project grant 2.2.8
文摘The effect of graded levels of phytase on performance, bone characteristics, excreta/litter quality and odorant emissions was examined using 720 Ross 308 male d-old broilers. A 2 x 4 factorial arrangement of treatments was employed with 6 replicates of 15 birds per pen. Factors were: diets-positive and negative control(PC, NC); phytase-0, 500,1,000.1,500 FTU/kg. The PC was formulated to meet the 2014 Ross 308 nutrient specifications, whereas the NC was formulated with lower Ca(-1.4 g/kg), available P(-1.5 g/kg), Na(-0.3 g/kg), dLys(-0.2 g/kg) and MEn(-0.28 MJ/kg) equivalent to nutrient matrix values for 500 FTU/kg phytase in the starter,grower and finisher periods(i.e.,downspec diet). On d 24, phytase decreased FCR by 1.6, 4.3 and 4.6 points at inclusion levels of 500.1,000 and 1,500 FTU/kg, respectively(P < 0.01) across all diets. Phytase by diet interactions on BW gain were observed on d 24 and 35(P < 0.01). The effect of phytase was much more pronounced in the NC diet as compared with the PC diet.On d 24, phytase increased BW gain by 37, 55 and 68 g in the PC and 127.233 and 173 g in the NC at 500,1,000 and 1,500 FTU/kg, respectively. Diet by phytase interactions were also observed for tibia ash, litter quality and water to feed intake ratio(P < 0.01) with higher phytase effect in NC as compared with PC.Neither diet nor phytase impacted excreta moisture content on d 18 or 21(P> 0.05). Solid phase microextraction gas chromatography-mass spectrometry(SPME-GC-MS) analysis of gaseous emissions on d 39 indicated no difference in the emission of alcohols, aldehydes, ketones, volatile fatty acids and phenols between treatments(P> 0.05). The results indicate that phytase has greater benefits when formulated using nutrient matrix values as compared with adding it over the top in an already nutrient sufficient diet. The later method would be expected to increase feed costs without concomitant performance benefits.
文摘Two studies were conducted to investigate the effect of Bacillus amyloliquefaciens CECr 5940(BA)as a probiotic on growth performance,amino acid digestibility and bacteria population in broiler chickens under a subclinical necrotic enteritis(NE)challenge and/or fed diets with different levels of crude protein(CP).Both studies consisted of a 2×2 factorial arrangement of treatments with 480 Ross 308 mix-sexed broiler chickens.In study 1,treatments included 1)NE challenge(+/),and 2)BA(1.0×106 CFU/g of feed)supplementation(+/-).In study 2,all birds were under NE challenge,and treatments were 1)CP level(Standard/Reduced[2%less than standard])and 2)BA(1.0×106 CFU/g of feed)supplementation(+/-).After inducing NE infection,blood samples were taken on d 16 for uric acid evaluation,and cecal samples were collected for bacterial enumeration.In both studies,ileal digesta was collected on d 35 for nutrient digestibility evaluation.In study 1,the NE challenge reduced body weight gain(BWG),supressed feed conversion ratio(FCR)and serum uric acid levels(P<0.001).Supplementation of BA increased BWG(P<0.001)and reduced FCR(P=0.043)across dietary treatments,regardless of challenge.Bacillus(P=0.030)and Ruminococcus(P=0.029)genomic DNA copy numbers and concentration of butyrate(P=0.017)were higher in birds fed the diets supplemented with BA.In study 2,reduced protein(RCP)diets decreased BWG(P=0.010)and uric acid levels in serum(P<0.001).Supplementation of BA improved BWG(P=0.001)and FCR(P=0.005)and increased Ruminococcus numbers(P=0.018)and butyrate concentration(P=0.033)in the ceca,regardless of dietary CP level.Further,addition of BA reduced Clostridium perfringens numbers only in birds fed with RCP diets(P=0.039).At d 35,BA sup-plemented diets showed higher apparent ileal digestibility of cystine(P=0.013),valine(P=0.020),and lysine(P=0.014).In conclusion,this study suggests positive effects of BA supplementation in broiler diets via modulating gut microflora and improving nutrient uptake.
基金supported under the Australian Government's Cooperative Research Centres Program(2.2.8)
文摘Abatement of odour emissions has become an important consideration to agricultural industries,including poultry production. The link between diet and odour emissions was studied in two experiments using Ross 308 male meat chickens reared in specially designed chambers in a climate controlled room. In the first experiment, two treatments were compared using three replicates of two birds per chamber. Two wheat-soy based treatment diets were formulated with or without canola seed, an ingredient rich in sulfur amino acids, Treatment 1(T1) had 13,39 MJ/kg ME(as fed) and used 60 g/kg canola seed without corn while Treatment 2(T2) contained 12.90 MJ/kg ME(as fed) and used 150 g/kg corn without canola seed. In the second experiment, birds were assigned to three dietary treatments of five replicates with five birds per replicate(chamber). The basal starter, grower and finisher diets in the control group(SBM group) contained soybean meal in the range of 227-291 g/kg(as fed) as the main protein source. The other treatments(CM and MBM groups) contained either high levels of canola meal(174-190 g/kg) or meat meal(74-110 g/kg) at the expense of soybean meal. In both experiments, diets were isocaloric, isonitrogenous and contained similar digestible amino acid contents as per 2007 Aviagen Ross 308 guidelines. Emissions of odour were measured using Fourier transform infrared(FTIR) spectroscopy. In both experiments, major odorous compounds detected included 2,3-butanedione(diacetyl),2-butanone, dimethyl disulfide, methyl mercaptan, ethyl mercaptan, 2-butanol, 3-methyl-butanal,phenol and m-cresol. In the first experiment, Tl(with canola seed) produced higher concentration of methyl mercaptan(P < 0.05) and lower diacetyl(P < 0.01) than T2. In the second experiment, methyl mercaptan emission was higher in SBM group(P = 0.01) and total elemental sulfur were higher in SBM and CM groups up to day 24(P < 0.01). Results of these experiments indicated a direct link between diet and odour emissions from meat chickens.
文摘The cost of feed represents an important part of the total cost in swine and poultry production(>60%)with energy accounting for at least 70%of feed cost.The energy value of ingredients or compound feeds can be estimated as digestible(DE),metabolisable(ME)and net energy(NE)in pigs and ME and NE in poultry.The current paper reviews the different methods for evaluating DE,ME and NE of feeds for monogastric animals and their difficulties and limits,with a focus on NE.In pigs and poultry,energy digestibility depends on the chemical characteristics of the feed,but also on technology(pelleting,for instance)and animal factors such as their health and body weight.The ME value includes the energy losses in urine that are directly dependent on the proportion of dietary N excreted in urine resulting in the concept of ME adjusted for a zero N balance(MEn)in poultry.For poultry,the concept of true ME(TME,TMEn),which excludes the endogenous fecal and urinary energy losses from the excreta energy,was also developed.The measurement of dietary NE is more complex,and NE values of a given feed depend on the animal and environmental factors and also measurement and calculation methods.The combination of NE values of diets obtained under standardised conditions allows calculating NE prediction equations that are applicable to both ingredients and compound feeds.The abundance of energy concepts,especially for poultry,and the numerous feed and animal factors of variation related to energy digestibility or ME utilisation for NE suggest that attention must be paid to the experimental conditions for evaluating DE,ME or NE content.This also suggests the necessity of standardisations,one of them being,as implemented in pigs,an adjustment of ME values in poultry for an N retention representative of modern production conditions(MEs).In conclusion,this review illustrates that,in addition to numerous technical difficulties for evaluating energy in pigs and poultry,the absolute energy values depend on feed and animal factors,the environment,and the methods and concepts.Finally,as implemented in pigs,the use of NE values should be the objective of a more reliable energy system for poultry feeds.
基金Jilin Academy of Agricultural Sciences(GXGC2017ZY002),ChinaAdministration of Foreign Experts Affairs(L20172200042 and 20182200010)for their financial support.
文摘Pea starch consists predominantly of C-type of amylopectin chain which is more resistant to digestive enzymes than A-type of starch thus slowly digested in poultry.It was hypothesized that the presence of slowly digested pea starch in broiler diets will increase net energy and the efficiency of energy utilization in broilers.Two experiments were performed to investigate starch digestibility of pea at different in-cubation times(in vitro study)and the effect of dietary pea on heat increment and net energy in broilers using an open-circuit respiratory calorimetry system(in vivo study).One-day-old Ross 308 male broilers were fed a common starter crumble from d 1 to 10 and standard grower diets thereafter.At d 21,birds were transferred to the chambers each housing 2 birds.Each treatment was replicated 6 times with 2 identical runs of 3 replicates per treatment.A wheat-soybean meal-based diet was used as a control and the treatment diet contained 500 g of pea/kg pea.In vitro study showed that pellet processing increased(P<0.001)starch digestibility,particularly at shorter times for wheat and a much larger response for pea.Birds offered the pea-based diet had lower(P=0.002)feed intake,lower(P=0.020)body weight gain,but a similar(P>0.05)FCR compared to those offered the wheat-based diet.Net energy(NE)and apparent metabolizable energy(AME)values were higher in the pea-based diet than in the wheat-based diet(P-0.037 for NE and P-0.018 for AME).Heat production,respiratory quotient,heat increment of feed,efficiency of utilization of gross energy for AME,and efficiency of utilization of AME for NE did not differ(P>0.05)between the 2 treatments.There was no effect(P>0.05)of pea on the total tract di-gestibilities of dry matter,crude protein and ash,but the total tract digestibility of starch was higher(P-0.022)in the pea-based diet compared to the wheat-based diet.This study provides insight into the energy metabolism of broilers offered a pea-based diet and indicates that dietary pea supplementation increases dietary AME and NE but has no effect on heat increment of feed and the efficiency of energy utilization in broilers.
基金The study was funded by Trouw Nutrition,a Nutreco company,The Netherlands.The authors thank Shuyu Song and Jonathon Clay for their technical assistance.The authors thank Ms.Petrina Young for providing Eimeria spp.oocysts and Prof.Robert Moore for providing Clostridium perfringens EHE-18.
文摘Controlling enteric diseases of broilers is crucial.Among many additives,organic acids(OA)and their blends are gaining attention to combat diseases in the post-antibiotic era.The current study evaluated the potentials of short-chain fatty acids(SCFA)and medium-chain fatty acids(MCFA)blends and/or phenolic compounds on intestinal integrity,intestinal pH,caecal microbiota,and caecal SCFA profiles of broilers under necrotic enteritis(NE)challenge.The additives used were:(A)a blend of SCFA,MCFA,and a phenolic compound(SMP),(B)a blend of free and buffered SCFA with MCFA(SMF),and(C)a blend of free and buffered SCFA with a high concentration of MCFA(SHM).A total of 1,404 male parental chicks of Ross 308 broilers were randomly allocated to 78 floor pens on hatching day with 6 treatments replicated 13 times with 18 birds per pen.The treatments were:UCC,unchallenged control;CHC,challenged control;BAC,challenged group plus zinc bacitracin;SMP,challenged group plus additive SMP;SMF,challenged group plus additive SMF;SHM,challenged group plus additive SHM.Birds were challenged with field-strain Eimeria spp.on d 9 and Clostridium perfringens on d 14.Birds challenged with NE increased fluorescein isothiocyanate dextran(FITC-d)concentration in serum,reduced acetate and butyrate concentrations,and increased Bacteroides and C.perfringens load in the caeca(P<0.05).Birds fed additives decreased FITC-d from gut to serum,reduced Bacteroides(d 16,P<0.05)and numerically reduced C.perfringens load compared to CHC group.Birds fed additive SHM had higher concentrations of acetate and butyrate(d 21,P<0.05)than CHC group but were not different from SMP and SMF groups.All the additives exhibited similar intestinal protection against NE compared to the BAC group indicated by FITC-d concentration in serum,acetate,propionate and butyrate concentrations in the caeca,and caecal bacterial loads except for the C.perfringens(P>0.05).The SMP group had a higher load compared to BAC(P<0.05).These findings suggest the promising effects of OA blends as alternatives to BAC to ameliorate the impact of NE challenge of broilers as indicated by improved intestinal health.
基金The study was funded by ADMi|Pancosma SA,A-One Business Center,Switzerland.
文摘Plant extracts(PE)are gaining increased attention as potential alternatives to in-feed antimicrobials(AM)due to their known antimicrobial activities.This study was conducted to examine the potential of PE,a microencapsulated product composed of eugenol and garlic tincture as an alternative to AM-agent on performance and intestinal health in broilers under necrotic enteritis(NE)challenge.A total of 960 dayold mixed-sex Cobb 500 chicks were randomly distributed to 48-floor pens with 6 treatments replicated 8 times with 20 birds each.The 6 treatments were as follows:UC,unchallenged control;CC,challenged control;PE,challenged group plus PE;AM,challenged group plus AM;FAP,challenged group plus a full dose of AM with PE;HAP,challenged group plus a half dose of AM with PE in starter,grower and finisher phases.Birds in the challenged groups were inoculated with Eimeria spp.on d 9 and Clostridium perfringens on d 14.The body weight gain(BWG),feed intake(FI),feed conversion ratio(FCR),and livability of birds were compromised,and intestinal lesions and mortality were increased(P<0.05)by NE challenge,illustrating a successful clinical NE challenge.Birds fed AM had higher BWG and FI,and lower FCR,mortality,and intestinal lesions compared to the CC group(P<0.05).Birds fed PE had improved FCR(P<0.05)and livability(5.8%)in an overall period compared to the CC group.On d 16,PE supplementation reduced ileal lesion scores in only male birds(P<0.05).Birds fed PE had decreased Eimeria maxima and Eimeria acervulina oocyst counts in caecal content(P<0.05).Birds fed PE had decreased Eimeria brunetti and total oocyst counts in caecal content,and E.acervulina oocyst counts in ileal content in only female birds(P<0.05).On d 35,PE supplementation reduced variation of BW in both male and female birds and increased yellowness(b*value,14.4%)in the thigh.These findings suggest the potential of PE supplementation in diets to improve the performance and intestinal health of birds under clinical NE as indicated by improved FCR,livability,uniformity,reduced ileal lesions,oocyst counts and increased skin yellowness.However,the protective effect of PE may not be apparent in the presence of AM in the feed.
文摘Subclinical necrotic enteritis(NE) is an economically important disease in the broiler industry. With the move towards removal of antibiotics from feeds, solutions to control subclinical NE are desperately being sought. Dietary glycine has been shown to promote proliferation of Clostridium perfringens(Cp) and may thus be useful to include in a NE challenge model. A study was conducted to evaluate the effect of increased dietary glycine levels on subclinical NE. A 2 × 2 × 2 factorial arrangement of treatments was carried out using day-old male Ross 308 chicks(n = 624) allocated to 48 floor pens with 8 treatments of 6 replicates with 11 birds per treatment. Factors were: Cp challenge(C-or C+), Eimeria spp. challenge(Eor E+), and dietary glycine in the grower diet(0 or 10 g/kg). Birds had higher FCR when challenged with Eimeria(P < 0.01) or Cp(P < 0.05) on d 24 or Cp on d 35 but FCR was lower when fed glycine on d 24(P < 0.01). Supplementation of glycine reduced feed intake on d 24 and increased weight gain on d 35(P < 0.05). A Cp × Eimeria × glycine interaction(P < 0.05) showed a higher jejunal lesion scores in birds challenged with a combination of Cp and glycine compared with those with Eimeria and glycine or the unchallenged birds. Lesion score interactions between Cp and glycine(P < 0.05) in the ileum and Cp and Eimeria in the duodenum(P < 0.05) and ileum(P < 0.05) illustrated higher lesion scores in birds challenged with Cp without Eimeria or glycine compared to those not challenged with Cp. This study suggests that using glycine can partially replace Eimeria in a subclinical NE challenge model in promoting the intestinal lesions but not impairing chicken performance.
文摘Broilers that have early access to feed have been shown to have enhanced immune system and gut development and heightened resilience against necrotic enteritis(NE). This study examined the effect of early feeding a high amino acid density diet on performance of broilers under a sub-clinical NE challenge model. Ross 308 broilers(n = 576) were assigned to a 2 × 2 × 2 factorial design with 2 feeding regimes(feed access either within 6 h post-hatch or after 48 h post-hatch), 2 diets(control diet or the control diet with an additional 10% digestible amino acids [HAA]) and either presence or absence of NE challenge.Oral administrations of Eimeria species(d 9) and a field strain of Clostridium perfringens(d 14) were used to induce NE, Broiler performance was analysed at d 13.23.30 and 35, Intestinal lesion score and bacterial count were analysed on d 16. The NE challenge reduced overall bird performance and induced severe intestinal lesions, without causing notable mortality. At d 23 bird weight was significantly lower(P < 0.001) in the challenged birds compared with the unchallenged birds, but by d 30 the challenged birds had recovered and challenge no longer had an impact on bird performance. Birds fed the HAA diet had greater body weight by d 35 and heightened Lactobacillus content in the ileum at d 16(P < 0.05).Birds that were fed the HAA diet after a period of fasting performed better in terms of feed conversion ratio(FCR) under challenge. The findings from this study suggest there are beneficial effects of feeding high amino acid diets to birds in response to external stresses, such as post-hatch fasting and subclinical NE.
文摘Necrotic enteritis(NE)is an important enteric disease in poultry and has become a major concern in poultry production in the post-antibiotic era.The infection with NE can damage the intestinal mucosa of the birds leading to impaired health and,thus,productivity.To gain a better understanding of how NE impacts the gut function of infected broilers,global mRNA sequencing(RNA-seq)was performed in the jejunum tissue of NE challenged and non-challenged broilers to identify the pathways and genes affected by this disease.Briefly,to induce NE,birds in the challenge group were inoculated with 1 mL of Eimeria species on day 9 followed by 1 mL of approximately 108 CFU/mL of a NetB producing Clostridium per-fringens on days 14 and 15.On day 16,2 birds in each treatment were randomly selected and euthanized and the whole intestinal tract was evaluated for lesion scores.Duodenum tissue samples from one of the euthanized birds of each replicate(n=4)was used for histology,and the jejunum tissue for RNA extraction.RNA-seq analysis was performed with an Illumina RNA HiSeq 2000 sequencer.The differ-entially expressed genes(DEG)were identified and functional analysis was performed in DAVID to find protein-protein interactions(PPI).At a false discovery rate threshold<0.05,a total of 377 DEG(207 upregulated and 170 downregulated)DEG were identified.Pathway enrichment analysis revealed that DEG were considerably enriched in peroxisome proliferator-activated receptors(PPAR)signaling(P<0.01)andβ-oxidation pathways(P<0.05).The DEG were mostly related to fatty acid metabolism and degradation(cluster of differentiation 36[CD36],acyl-CoA synthetase bubblegum family member-1[ACSBG1],fatty acid-binding protein-1 and-2[FABP1]and[FABP2];and acyl-coenzyme A synthetase-1[ACSL1]),bile acid production and transportation(acyl-CoA oxidase-2[ACOX2],apical sodium-bile acid transporter[ASBT])and essential genes in the immune system(interferon-,[IFN-γ],LCK proto-oncogene,Src family tyrosine kinase[LCK],zeta chain of T cell receptor associated protein kinase 70 kDa[ZAP70],and aconitate decarboxylase 1[ACOD1]).Our data revealed that pathways related to fatty acid digestion were significantly compromised which thereby could have affected metabolic and immune responses in NE infected birds.
文摘Artificial gut models including both the gastric and intestinal phases have been used in poultry research for decades to predict the digestibility of nutrients,the efficacy of feed enzymes and additives,and caecal fermentation.However,the models used in the past are static and cannot be used to predict interactions between the feed,gut environment and microbiome.It is imperative that a standard artificial gut model for poultry is established,to enable these interactions to be examined without continual reliance on animals.To ensure the validity of an artificial model,it should be validated with in vivo studies.This review describes current practices in the use of artificial guts in research,their importance in poultry nutrition studies and highlights an opportunity to develop a dynamic gut model for poultry to reduce the number of in vivo experiments.
基金The authors gratefully acknowledge Adisseo France for financial support of this study.
文摘This study evaluated the effect of multi-carbohydrase(MC)on energy and nitrogen(N)balance and gene expression in broilers fed diets with different crude protein(CP)contents.The study employed a 2×2 factorial arrangement of treatments.The factors were presence or absence of MC,and standard(SCP)or low(LCP)dietary CP concentration.A 3-phase feeding program was used,including starter(0 to 7 d),grower(8 to 17 d)and finisher(18 to 28 d)phases.The study was undertaken in closed calorimetry chambers.Each of the 4 dietary treatments was replicated 8 times in total across 2 runs,with 2 birds per replicate(n=64).Data for energy partitioning and N balance were collected from d 25 to 28.On d 28,birds were euthanized to collect muscle and intestinal tissue samples for gene expression.The results showed that the MC increased apparent metabolizable energy(AME,P<0.01)and net energy(NE,P<0.05),and reduced the feed conversion ratio(FCR,P<0.01)in all diets.The proportion of energy retained as fat per total energy retention(REf/RE)was positively correlated with feed AME and NE(r=0.541,P<0.01 and r=0.665,P<0.001,respectively),suggesting that feed energy augmented with increased fat gain.Muscle ATP synthase subunit alpha(ATPSA1W)gene expression had a positive cor-relation with REf/RE and feed NE(r=0.587,P<0.001 and r=0.430,P<0.05,respectively).Similarly,muscle peroxisome proliferator-activated receptor gamma coactivator 1 alpha(PGC-1A)expression was negatively correlated with weight gain and positively correlated with FCR(r-0.451,P<0.05 and r-0.359,P<0.05,respectively).These correlations show that over-expressions of muscle genes related to energy production reduce bird performance.This study demonstrated that MC increase dietary energy utilization,regardless of dietary CP concentration.However,the energy released by the enzymes in-creases feed energy-to-CP ratio,meaning there is excess energy that is then deposited as body fat.This suggests that supplemental MC in broiler feeds is beneficial if diets are formulated to contain marginal energy levels.
