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
Poultry feed contains significant amounts of undigested components,driving the search for innovative strategies to improve their utilization.This study aimed to evaluate the effects of β-mannanase,alone or in combina...Poultry feed contains significant amounts of undigested components,driving the search for innovative strategies to improve their utilization.This study aimed to evaluate the effects of β-mannanase,alone or in combination with a xylanase and β-glucanase preparation(XG),on growth performance,nutrient and energy utilization,and the gastrointestinal environment of broilers fed maize-based diets.A total of 384 mixed-sex Cobb 500 d-old broilers were assigned to 4 treatments for 35 days in a 2×2 factorial arrangement,with β-mannanase(with or without)and XG(with or without)as factors.Each treatment included eight replicate pens of 12 birds each,totalling 96 birds per treatment.During d 0 to 10,dietary supplementation of β-mannanase increased weight gain(P=0.009)and improved feed conversion ratio(FCR)(P<0.001)compared to the unsupplemented control.During d 11 to 21,β-mannanase improved FCR(P=0.039),and β-mannanase and XG interacted for weight gain(P=0.008),whereβ-mannanase or XG alone increased weight gain compared to the unsupplemented control but there were no further improvements achieved via their simultaneous use.During d 22 to 35,XG supplementation increased weight gain(P=0.003)and improved FCR(P=0.032).During d 0 to 35,XG improved FCR(P=0.019),and XG and β-mannanase tended to interact for FCR(P=0.071),with either of the enzymes improving FCR compared to the unsupplemented control but with no further improvements when added in tandem.During d 0 to 35,XG and β-mannanase interacted for weight gain(P=0.026),where XG improved weight gain in the absence of β-mannanase but there were no further improvements achieved via their simultaneous use.Dietary β-mannanase increased total tract retentions of dry matter(P=0.001),insoluble non-starch polysaccharides(NSP,P=0.010),total NSP(P=0.010),calcium(P=0.020),apparent metabolizable energy(AME,P<0.001)and nitrogen-corrected AME(AME n,P<0.001).Dietary β-mannanase and XG interacted for acetic acid(P=0.034)and total shortchain fatty acid(SCFA,P=0.044)concentrations in the caecal contents,where β-mannanase increased their concentrations in the absence of XG,but there were no further improvements when both enzymes were used in tandem.In conclusion,the supplementation of β-mannanase in a maize-based diet improved growth performance in the early stages of broiler development by enhancing the utilization of NSP,nutrients,and energy.On the other hand,XG improved growth performance in the grower-finisher stages;however,in this study,the combination of β-mannanase and XG did not produce synergistic effects on growth performance or nutrient and energy utilization in broilers fed maize-based diets.展开更多
Nutritional strategies to enhance the utilization of undigested dietary components for sustainability and better production efficiency are constantly being explored in poultry.This study aimed to investigate the effec...Nutritional strategies to enhance the utilization of undigested dietary components for sustainability and better production efficiency are constantly being explored in poultry.This study aimed to investigate the effects of β-mannanase alone or in combination with a xylanase and β-glucanase preparation on growth performance,nutrient and energy utilization,and gastrointestinal environment of broilers offered wheat-based diets.At d 0 post-hatch,384 mixed-sex Cobb 500 broilers were assigned to 4 treatments in a 2×2 factorial arrangement,with β-mannanase(with or without)and xylanase+β-glucanase(XG,with or without)as the 2 factors.Each treatment contained 8 replicates of 12 birds per pen and 96 birds per treatment.During d 0 to 10,birds offered diets supplemented with XG(P=0.023)or β-mannanase(P=0.010)had higher weight gain,andβ-mannanase supplementation improved(P=0.040)feed conversion ratio(FCR)compared to the unsupplemented control.During d 0 to 35,XG increased(P=0.035)and β-mannanase tended(P=0.096)to increase the weight gain of birds.The combination of β-mannanase and XG interacted(P=0.016)for FCR where either XG or β-mannanase alone improved FCR compared to the unsupplemented control but there were no further improvements when they were added in tandem.At d 21,XG decreased(P<0.001)ileal digesta viscosity,and XG(P<0.001)or β-mannanase(P=0.004)decreased ileal pH.β-Mannanase increased total tract retention of dry matter(DM,P=0.001),nitrogen(N,P=0.019),soluble non-starch polysaccharides(NSP,P=0.020),insoluble NSP(P<0.001),total NSP(P<0.001),free oligosaccharides(P=0.023),calcium(Ca,P<0.001),and showed tendency(P=0.098)to increase nitrogen-corrected apparent metabolizable energy(AMEn).Dietary XG increased apparent total tract retention of DM(P=0.017),soluble NSP(P<0.001),Ca(P=0.005),apparent metabolizable energy(AME)(P=0.024),and AMEn(P=0.020).β-Mannanase and XG combination showed a tendency(P=0.073)to interact for AME such that the highest AME was observed in this group.β-Mannanase and XG combination interacted(P=0.034)for butyric acid concentration in the caecal contents where β-mannanase or XG alone increased the concentration of butyric acid compared to the unsupplemented control which was further enhanced when they were added in tandem.β-Mannanase(P=0.049)or XG(P=0.046)increased total short-chain fatty acid concentration in the caecal contents.These findings suggest that dietary supplementation of β-mannanase or XG alone provided comparable growth performance benefits and positively affected the gut environment,however,their combination further enhanced energy utilization and butyric acid production,and the latter may have implications in broiler's gut health and immune response.展开更多
Insoluble fibre has been shown to be a functional fibre that helps the effective use of nutrients and energy through the gastrointestinal tract,and as such may be added to diets to enhance the growth performance of br...Insoluble fibre has been shown to be a functional fibre that helps the effective use of nutrients and energy through the gastrointestinal tract,and as such may be added to diets to enhance the growth performance of broilers.This study aimed to investigate the effects of insoluble fibre sources in a reduced protein(RP)diet fed to broilers.At d 10 post-hatch,672 d-old Ross 308 male birds were assigned to 6 treatments with 8 replicates of 14 birds each.The treatments were a normal protein(NP)diet,a RP diet(-20 g/kg protein),and RP diets formulated with either sugarcane bagasse at 20 g/kg,lignocellulose-based fibre at 10 g/kg,oat hulls at 30 g/kg,or soy hulls at 30 g/kg.The results showed that the reduction in dietary protein decreased feed intake and weight gain,and worsened feed conversion ratio(FCR;P<0.05).The birds fed the RP diet with soy hulls or bagasse had a better FCR(P<0.05)compared to those fed the RP diet without fibre and similar FCR to those fed a NP diet.Bagasse or soy hulls supplementation in the RP diet decreased(P<0.05)the starch digestibility coefficient compared to the RP diet without fibre.Lower counts(P<0.05)of Lactobacillus in birds offered the RP diet with bagasse or oat hulls was observed compared to the RP diet alone.The difference(P=0.011)in the expression of digestive enzyme genes in response to dietary treatments was observed for the AMY2A gene in the pancreas.The reduction in dietary crude protein(CP)downregulated(P<0.05)the AMY2A gene and the addition of the four insoluble fibres to the RP diet had no effect on the expression of AMY2A compared to the RP treatment but bagasse,lignocellulose,and soy hulls added RP diets had similar AMY2A expression as the NP treatment.It was concluded that reducing dietary protein compromised the growth performance of broilers which was partially attenuated by supplementing the diets with bagasse or soy hulls.展开更多
Feedstuffs derived from canola,predominantly canola meals plus whole,"full-fat"canola seed,and even canola protein isolates and/or concentrates,have the potential to decrease soybean meal inclusions in diets...Feedstuffs derived from canola,predominantly canola meals plus whole,"full-fat"canola seed,and even canola protein isolates and/or concentrates,have the potential to decrease soybean meal inclusions in diets for broiler chickens.The protein content of soybean meal exceeds that of canola meal;however,canola meal contains more methionine and cysteine in absolute and relative terms.The purpose of this review is to explore this potential as Australian chicken-meat production is uniquely positioned to take advantage of this opportunity to the extent that it can be realised.Australia harvests ample quantities of canola,the bulk of which is exported as seed;alternatively,soybean production is very limited;therefore,large quantities of soybean meal are imported as the principal source of dietary protein for broiler chickens.This importation of soybean meal is not sustainable;however,canola meal inclusions in broiler diets do not usually exceed 100 g/kg.Regression equations derived from 15 recent studies indicate that dietary inclusions of 150 g/kg solvent-extracted canola meal would compromise weight gain by 4.04%and feed conversion ratio (FCR) by 4.72%.The foremost factors driving these depressions in canola meal are probably (1) high fibre contents coupled with low energy densities and (2) the presence of glucosinolates,which may be converted into toxic metabolites including thiocyanates.Moreover,regression equations from nine studies suggest that calculated dietary glucosinolate concentrations of 2.00μmol/g would compromise weight gain by 5.72%and FCR by 6.56%.The nutritive value of canola meal could be enhanced by improvements in canola breeding programs,processing methods in canola meal production,and dietary formulations including judicious application of exogenous enzymes.Consideration is given to these aspects in this review as any improvements would increase the extent to which canola meal can feasibly replace soybean meal in broiler diets.An additional pathway to decrease the reliance on soybean meal could be the adoption of reduced-crude protein (CP) diets containing canola meal.The combined strategy of canola meal replacing soybean meal in reduced-CP diets,if successful,would tangibly decrease soybean meal requirements in global chicken-meat production.展开更多
This study aimed to investigate the limitations and interactive effects of dietary crude protein(CP;15%,17%and 19%),excess branched-chain amino acid(BCAA)inclusions(0%,20%and 40%),and net energy(NE;9.0,9.7 and 10.4 MJ...This study aimed to investigate the limitations and interactive effects of dietary crude protein(CP;15%,17%and 19%),excess branched-chain amino acid(BCAA)inclusions(0%,20%and 40%),and net energy(NE;9.0,9.7 and 10.4 MJ/kg)on performance and nutrient utilization for Cobb 500 mix-sex broilers,using a Box-Behnken design.The study consisted of 2 experiments:Exp.1 involved 1092 chickens,and their performance was measured from d 19 to 35,and Exp.2 employed 156 birds for NE measurements from d 25 to 28.Both experiments used the same diets(n=13),each replicated 7 times for Exp.1 and 6 times for Exp.2.On d 35,4 birds per pen(2 males and 2 females)were sampled to collect ileal digesta and weigh carcass parts.Feed intake(FI),NE intake(NEi),weight gain(WG),feed conversion ratio(FCR)and breast yield were affected by CP×NE(P<0.001)and CP×BCAA(P=0.041).Diluting NE in the reduced CP(RP)-diets led to a higher FI(P<0.001)and breast yield(P<0.001)than high NE,but the NE levels had no effect(P>0.05)on FI and breast yield in high CP(HCP)-diets.Breast yield increased(P=0.041)with BCAA in HCP-diets,whereas in the RP-diets,the yield lowered(P=0.041)with increased BCAA.A similar trend was observed with fat content:in HCP-diets,fat content increased(P=0.007)with BCAA,while in RP-diets,fat content decreased(P=0.007)with higher BCAA levels.In addition,increasing BCAA in the RP-diets decreased(P<0.001)FI,NEi,WG and increased FCR(P=0.001)than low BCAA.However,BCAA levels had no effect(P>0.05)on these measurements in HCP-diets.High NE increased(P<0.001)NEi and decreased(P<0.001)FCR compared to low NE in the HCP-diets.However,the NE effect on both measurements did not differ(P>0.05)in RP-diets.These results indicate that increasing BCAA levels beyond the recommended amounts in RP-diets impairs energy utilization,leading to poor performance.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
Insufficient supply, high prices and competition with the human food and biofuel industries means there is a continuous demand for alternative energy sources for poultry. As a result, cassava is becoming an increasing...Insufficient supply, high prices and competition with the human food and biofuel industries means there is a continuous demand for alternative energy sources for poultry. As a result, cassava is becoming an increasingly important ingredient in poultry diets, largely due to its high availability. Efficient use of cassava products has been shown to reduce feed costs of poultry production. The utilisation of cassava is,however, limited by a number of factors, including its high fibre and low energy content and the presence of anti-nutritional factors, primarily hydrocyanic acid(HCN). With correct processing the inclusion level of cassava in poultry diets could be increased. Extensive research has been conducted on cassava products for poultry, but there is still a lack of consistency amongst the measured nutritive values for cassava and its products, hence variation exists in results from poultry studies. This paper reviews the nutrient composition of cassava products and its value as an alternative energy source in poultry diets.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
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
Poultry production has undergone a substantial increase compared to the livestock industries since 1970.However, the industry worldwide is now facing challenges with the removal of in-feed antibiotics completely or gr...Poultry production has undergone a substantial increase compared to the livestock industries since 1970.However, the industry worldwide is now facing challenges with the removal of in-feed antibiotics completely or gradually, as the once well-controlled poultry diseases have re-emerged to cause tremendous loss of production. Necrotic enteritis(NE) is one of the most important diseases which costs the industry over two billion dollars annually. In this paper, we review the progress on the etiology of NE and its control through dietary modifications, pre-and probiotics, short chain fatty acids, and vaccination. The other likely measures resulted in the most advances in the toxin characterization are also discussed. Vaccine strategies may have greater potential for the control of NE mainly due to clearer etiology of NE having been elucidated in recent years with the identification of necrotic enteritis toxin B-like(NetB) toxin. Therefore, the use of alternatives to in-feed antibiotics with a better understanding of the relationship between nutrition and NE, and limiting exposure to infectious agents through biosecurity and vaccination, might be a tool to reduce the incidence of NE and to improve gut health in the absence of in-feed antibiotics. More importantly, the combinations of different measures may achieve greater protection of birds against the disease. Among all the alternatives investigated, prebiotics, organic acids and vaccination have shown improved gastrointestinal health and thus, have potential for the control of NE.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
Different energy systems have been proposed for energy evaluation of feeds for domestic animals.The oldest and most commonly used systems take into account the fecal energy loss to obtain digestible energy(DE),and fec...Different energy systems have been proposed for energy evaluation of feeds for domestic animals.The oldest and most commonly used systems take into account the fecal energy loss to obtain digestible energy(DE),and fecal,urinary and fermentation gases energy losses to calculate metabolizable energy(ME).In the case of ruminants and pigs,the net energy(NE)system,which takes into account the heat increment associated with the metabolic utilization of ME,has progressively replaced the DE and ME systems over the last 50 years.For poultry,apparent ME(AME)is used exclusively and NE is not yet used widely.The present paper considers some important methodological points for measuring NE in poultry feeds and summarizes the available knowledge on NE systems for poultry.NE prediction equations based on a common analysis of three recent studies representing a total of 50 complete and balanced diets fed to broilers are proposed;these equations including the AME content and easily available chemical indicators have been validated on another set of 30 diets.The equations are applicable to both ingredients and complete diets.They rely primarily on an accurate and reliable AME value which then represents the first limiting predictor of NE value.Our analysis indicates that NE would be a better predictor of broiler performance than AME and that the hierarchy between feeds is dependent on the energy system with a higher energy value for fat and a lower energy value for protein in an NE system.Practical considerations for implementing such an NE system from the commonly used AME or AMEn(AME adjusted for zero nitrogen balance)systems are presented.In conclusion,there is sufficient information to allow the implementation of the NE concept in order to improve the accuracy of feed formulation in poultry.展开更多
An experiment was conducted to explore the effects of digestible amino acid(dAA)concentrations and supplemental protease on live performance and energy partitioning in broilers.Ross 308 male broilers(n?288)were distri...An experiment was conducted to explore the effects of digestible amino acid(dAA)concentrations and supplemental protease on live performance and energy partitioning in broilers.Ross 308 male broilers(n?288)were distributed into 24 floor pens and offered 1 of 4 dietary treatments with 6 replicates from 1 to 35 d of age.Dietary treatments consisted of a 2×2 factorial arrangement with dAA concentrations(standard and reduced[34 g/kg below standard])and supplemental protease(without or with)as the main factors.At 1,15,28,and 35 d of age,feed and broilerswereweighed to determine live performance.From20 to 23 d of age,a total of 32 birds(2 birds/chamber,4 replicates)were placed in closed-calorimeter chambers to determine respiratory exchange(heat production,HP),apparent metabolisable energy(AME),retained energy(RE),and net energy(NE).From 29 to 35 d of age,supplemental protease in the reduced-dAA diet decreased broiler feed conversion ratio(FCR)by 5.6 points,whereas protease supplementation in the standard-dAA diet increased FCR by 5.8 points.The indirect calorimetry assay revealed that supplemental protease decreased(P<0.05)the heat increment of feed(HIF)by 0.22 MJ/kg.Also,from 20 to 23 d of age,broilers offered the reduced-dAA diet with supplemental protease had a higher daily body weight gain(BWG)(t10.4%),N intake(t7.1%),and N retention(t8.2%)than those offered the standard-dAA with supplemental protease.Broilers offered the reduced-dAA without supplemental protease exhibited a 3.6%higher AME-to-crude protein(CP)ratio than those offered other treatments.Protease supplementation in the standard-and reduced-dAA diets resulted in 2.7%and 5.6%lower AME intake-to-N retention ratios,respectively,compared with the unsupplemented controls.Reduced-dAA increased(P<0.05)AME intake(t4.8%),RE(t9.8%),NE intake(t5.8%),NE intake-to-CP ratio(t3.0%),and RE fat-to-RE ratio(t8.6%).Protease supplementation increased(P<0.05)respiratory quotient(t1.2%)and N retention-to-N intake ratio(t2.2%),NE-to-AME ratio(t1.9%),and reduced HP(3.6%),heat increment(7.4%),and NE intake-to-N retention(2.5%).In conclusion,protease positively affected FCR and energy partitioning in broilers;responses were most apparent in diets with reduced-dAA concentrations.展开更多
A total of 294 one-day-old Cobb broiler chickens were used to investigate the effects of four Lactobacillus strains on gut microbial profile and production performance. The six dietary treatments, each with 7 replicat...A total of 294 one-day-old Cobb broiler chickens were used to investigate the effects of four Lactobacillus strains on gut microbial profile and production performance. The six dietary treatments, each with 7 replicates were: 1) basal diet(negative control), 2) one of four strains of Lactobacillus(tentatively identified as Lactobacillus johnsonii, Lactobacillus crispatus, Lactobacillus salivarius and an unidentified Lactobacillus sp.) and 3) basal diet with added zinc-bacitracin(ZnB, 50 mg/kg). Results showed that the addition of probiotic Lactobacillus spp. to the feed did not significantly improve weight gain, feed intake and feed conversion rate(FCR) of broiler chickens raised in cages during the 6-week experimental period,but tended to increase the number of total anaerobic bacteria in the ileum and caeca, and the number of lactic acid bacteria and lactobacilli in the caeca; and to significantly increase the small intestinal weight(jejunum and ileum). Furthermore, all 4 probiotics tended to reduce the number of Enterobacteria in the ileum, compared with the control treatments. The probiotics did not affect the p H and the concentrations of short chain fatty acids(SCFA) and lactic acid in both the ileum and caeca.展开更多
The present study investigated whether supplementing fibre-degrading enzymes can ameliorate the severity of subclinical necrotic enteritis(NE)in broiler chickens offered wheat-or maize-based diets.A total of 1,544 mix...The present study investigated whether supplementing fibre-degrading enzymes can ameliorate the severity of subclinical necrotic enteritis(NE)in broiler chickens offered wheat-or maize-based diets.A total of 1,544 mixed-sex broiler chickens were assigned to 16 experimental treatments as a 2×2×4 factorial arrangement of treatments.The factors were the following:NE challenge,yes or no;diet type,wheat-or maize-based;and enzyme supplementation,control(no enzyme),family 10 xylanase(XYN10),family 11 xylanase(XYN11)or b-mannanase(MAN).Each treatment was replicated 6 times,with 16 birds per replicate pen.A three-way challenge×diet type×enzyme interaction occurred for body weight at 21 d of age(P=0.025)and overall feed conversion ratio(P=0.001).In the non-challenged birds fed the wheat-based diet,supplementing MAN increased d 21 body weight compared to the control.In challenged birds fed the maize-based diet,supplemental XYN11 impeded body weight and overall FCR compared to the control.Birds offered the maize-based diet presented heavier relative gizzard weights at both 16 and 21 d of age(P<0.001)and reduced liveability(P=0.046)compared to those fed the wheatbased diet.Enzyme supplementation reduced ileal and jejunal digesta viscosity at 16 d of age only in birds fed the wheat-based diet(P<0.001).XYN11 increased ileal digesta viscosity in birds fed the maizebased diet,and MAN reduced it in birds fed the wheat-based diet at 21 d of age(P=0.030).Supplementing XYN11 improved ileal soluble non-starch polysaccharides(NSP)digestibility in birds fed the wheat-based diet compared to non-supplemented birds(P<0.001).Birds fed the wheat-based diet displayed a higher abundance of Bifidobacterium,Lactobacillus and Enterobacteriaceae and butyric acid in the caeca at 16 d of age compared to birds fed the maize-based diet(P<0.05).In conclusion,supplemental XYN11 exacerbated the negative impact of NE on growth performance in birds fed the maizebased diet.Supplementing wheat-based diets with fibre-degrading enzymes ameliorates production losses induced by NE.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
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funded by BASF Animal Nutrition,Germany(Project code:BASF SE TID 26-22).
文摘Poultry feed contains significant amounts of undigested components,driving the search for innovative strategies to improve their utilization.This study aimed to evaluate the effects of β-mannanase,alone or in combination with a xylanase and β-glucanase preparation(XG),on growth performance,nutrient and energy utilization,and the gastrointestinal environment of broilers fed maize-based diets.A total of 384 mixed-sex Cobb 500 d-old broilers were assigned to 4 treatments for 35 days in a 2×2 factorial arrangement,with β-mannanase(with or without)and XG(with or without)as factors.Each treatment included eight replicate pens of 12 birds each,totalling 96 birds per treatment.During d 0 to 10,dietary supplementation of β-mannanase increased weight gain(P=0.009)and improved feed conversion ratio(FCR)(P<0.001)compared to the unsupplemented control.During d 11 to 21,β-mannanase improved FCR(P=0.039),and β-mannanase and XG interacted for weight gain(P=0.008),whereβ-mannanase or XG alone increased weight gain compared to the unsupplemented control but there were no further improvements achieved via their simultaneous use.During d 22 to 35,XG supplementation increased weight gain(P=0.003)and improved FCR(P=0.032).During d 0 to 35,XG improved FCR(P=0.019),and XG and β-mannanase tended to interact for FCR(P=0.071),with either of the enzymes improving FCR compared to the unsupplemented control but with no further improvements when added in tandem.During d 0 to 35,XG and β-mannanase interacted for weight gain(P=0.026),where XG improved weight gain in the absence of β-mannanase but there were no further improvements achieved via their simultaneous use.Dietary β-mannanase increased total tract retentions of dry matter(P=0.001),insoluble non-starch polysaccharides(NSP,P=0.010),total NSP(P=0.010),calcium(P=0.020),apparent metabolizable energy(AME,P<0.001)and nitrogen-corrected AME(AME n,P<0.001).Dietary β-mannanase and XG interacted for acetic acid(P=0.034)and total shortchain fatty acid(SCFA,P=0.044)concentrations in the caecal contents,where β-mannanase increased their concentrations in the absence of XG,but there were no further improvements when both enzymes were used in tandem.In conclusion,the supplementation of β-mannanase in a maize-based diet improved growth performance in the early stages of broiler development by enhancing the utilization of NSP,nutrients,and energy.On the other hand,XG improved growth performance in the grower-finisher stages;however,in this study,the combination of β-mannanase and XG did not produce synergistic effects on growth performance or nutrient and energy utilization in broilers fed maize-based diets.
基金funded by BASF SE Animal Nutrition,Ludwigshafen,Germany.
文摘Nutritional strategies to enhance the utilization of undigested dietary components for sustainability and better production efficiency are constantly being explored in poultry.This study aimed to investigate the effects of β-mannanase alone or in combination with a xylanase and β-glucanase preparation on growth performance,nutrient and energy utilization,and gastrointestinal environment of broilers offered wheat-based diets.At d 0 post-hatch,384 mixed-sex Cobb 500 broilers were assigned to 4 treatments in a 2×2 factorial arrangement,with β-mannanase(with or without)and xylanase+β-glucanase(XG,with or without)as the 2 factors.Each treatment contained 8 replicates of 12 birds per pen and 96 birds per treatment.During d 0 to 10,birds offered diets supplemented with XG(P=0.023)or β-mannanase(P=0.010)had higher weight gain,andβ-mannanase supplementation improved(P=0.040)feed conversion ratio(FCR)compared to the unsupplemented control.During d 0 to 35,XG increased(P=0.035)and β-mannanase tended(P=0.096)to increase the weight gain of birds.The combination of β-mannanase and XG interacted(P=0.016)for FCR where either XG or β-mannanase alone improved FCR compared to the unsupplemented control but there were no further improvements when they were added in tandem.At d 21,XG decreased(P<0.001)ileal digesta viscosity,and XG(P<0.001)or β-mannanase(P=0.004)decreased ileal pH.β-Mannanase increased total tract retention of dry matter(DM,P=0.001),nitrogen(N,P=0.019),soluble non-starch polysaccharides(NSP,P=0.020),insoluble NSP(P<0.001),total NSP(P<0.001),free oligosaccharides(P=0.023),calcium(Ca,P<0.001),and showed tendency(P=0.098)to increase nitrogen-corrected apparent metabolizable energy(AMEn).Dietary XG increased apparent total tract retention of DM(P=0.017),soluble NSP(P<0.001),Ca(P=0.005),apparent metabolizable energy(AME)(P=0.024),and AMEn(P=0.020).β-Mannanase and XG combination showed a tendency(P=0.073)to interact for AME such that the highest AME was observed in this group.β-Mannanase and XG combination interacted(P=0.034)for butyric acid concentration in the caecal contents where β-mannanase or XG alone increased the concentration of butyric acid compared to the unsupplemented control which was further enhanced when they were added in tandem.β-Mannanase(P=0.049)or XG(P=0.046)increased total short-chain fatty acid concentration in the caecal contents.These findings suggest that dietary supplementation of β-mannanase or XG alone provided comparable growth performance benefits and positively affected the gut environment,however,their combination further enhanced energy utilization and butyric acid production,and the latter may have implications in broiler's gut health and immune response.
基金Agrifutures Australia(Project Number PRJ-011549)for their financial support。
文摘Insoluble fibre has been shown to be a functional fibre that helps the effective use of nutrients and energy through the gastrointestinal tract,and as such may be added to diets to enhance the growth performance of broilers.This study aimed to investigate the effects of insoluble fibre sources in a reduced protein(RP)diet fed to broilers.At d 10 post-hatch,672 d-old Ross 308 male birds were assigned to 6 treatments with 8 replicates of 14 birds each.The treatments were a normal protein(NP)diet,a RP diet(-20 g/kg protein),and RP diets formulated with either sugarcane bagasse at 20 g/kg,lignocellulose-based fibre at 10 g/kg,oat hulls at 30 g/kg,or soy hulls at 30 g/kg.The results showed that the reduction in dietary protein decreased feed intake and weight gain,and worsened feed conversion ratio(FCR;P<0.05).The birds fed the RP diet with soy hulls or bagasse had a better FCR(P<0.05)compared to those fed the RP diet without fibre and similar FCR to those fed a NP diet.Bagasse or soy hulls supplementation in the RP diet decreased(P<0.05)the starch digestibility coefficient compared to the RP diet without fibre.Lower counts(P<0.05)of Lactobacillus in birds offered the RP diet with bagasse or oat hulls was observed compared to the RP diet alone.The difference(P=0.011)in the expression of digestive enzyme genes in response to dietary treatments was observed for the AMY2A gene in the pancreas.The reduction in dietary crude protein(CP)downregulated(P<0.05)the AMY2A gene and the addition of the four insoluble fibres to the RP diet had no effect on the expression of AMY2A compared to the RP treatment but bagasse,lignocellulose,and soy hulls added RP diets had similar AMY2A expression as the NP treatment.It was concluded that reducing dietary protein compromised the growth performance of broilers which was partially attenuated by supplementing the diets with bagasse or soy hulls.
基金supported by the AgriFutures Chicken Meat Consortium-Nutrition,Gut Health and Environment project (PRO-016111) which is funded and supported by the AgriFutures Chicken Meat Program with its associated levy payers,five research providers,seven industry partners and nine international universities
文摘Feedstuffs derived from canola,predominantly canola meals plus whole,"full-fat"canola seed,and even canola protein isolates and/or concentrates,have the potential to decrease soybean meal inclusions in diets for broiler chickens.The protein content of soybean meal exceeds that of canola meal;however,canola meal contains more methionine and cysteine in absolute and relative terms.The purpose of this review is to explore this potential as Australian chicken-meat production is uniquely positioned to take advantage of this opportunity to the extent that it can be realised.Australia harvests ample quantities of canola,the bulk of which is exported as seed;alternatively,soybean production is very limited;therefore,large quantities of soybean meal are imported as the principal source of dietary protein for broiler chickens.This importation of soybean meal is not sustainable;however,canola meal inclusions in broiler diets do not usually exceed 100 g/kg.Regression equations derived from 15 recent studies indicate that dietary inclusions of 150 g/kg solvent-extracted canola meal would compromise weight gain by 4.04%and feed conversion ratio (FCR) by 4.72%.The foremost factors driving these depressions in canola meal are probably (1) high fibre contents coupled with low energy densities and (2) the presence of glucosinolates,which may be converted into toxic metabolites including thiocyanates.Moreover,regression equations from nine studies suggest that calculated dietary glucosinolate concentrations of 2.00μmol/g would compromise weight gain by 5.72%and FCR by 6.56%.The nutritive value of canola meal could be enhanced by improvements in canola breeding programs,processing methods in canola meal production,and dietary formulations including judicious application of exogenous enzymes.Consideration is given to these aspects in this review as any improvements would increase the extent to which canola meal can feasibly replace soybean meal in broiler diets.An additional pathway to decrease the reliance on soybean meal could be the adoption of reduced-crude protein (CP) diets containing canola meal.The combined strategy of canola meal replacing soybean meal in reduced-CP diets,if successful,would tangibly decrease soybean meal requirements in global chicken-meat production.
基金funded by Adisseo France in partnership with AgriFutures Australia and Poultry Hub Australia.
文摘This study aimed to investigate the limitations and interactive effects of dietary crude protein(CP;15%,17%and 19%),excess branched-chain amino acid(BCAA)inclusions(0%,20%and 40%),and net energy(NE;9.0,9.7 and 10.4 MJ/kg)on performance and nutrient utilization for Cobb 500 mix-sex broilers,using a Box-Behnken design.The study consisted of 2 experiments:Exp.1 involved 1092 chickens,and their performance was measured from d 19 to 35,and Exp.2 employed 156 birds for NE measurements from d 25 to 28.Both experiments used the same diets(n=13),each replicated 7 times for Exp.1 and 6 times for Exp.2.On d 35,4 birds per pen(2 males and 2 females)were sampled to collect ileal digesta and weigh carcass parts.Feed intake(FI),NE intake(NEi),weight gain(WG),feed conversion ratio(FCR)and breast yield were affected by CP×NE(P<0.001)and CP×BCAA(P=0.041).Diluting NE in the reduced CP(RP)-diets led to a higher FI(P<0.001)and breast yield(P<0.001)than high NE,but the NE levels had no effect(P>0.05)on FI and breast yield in high CP(HCP)-diets.Breast yield increased(P=0.041)with BCAA in HCP-diets,whereas in the RP-diets,the yield lowered(P=0.041)with increased BCAA.A similar trend was observed with fat content:in HCP-diets,fat content increased(P=0.007)with BCAA,while in RP-diets,fat content decreased(P=0.007)with higher BCAA levels.In addition,increasing BCAA in the RP-diets decreased(P<0.001)FI,NEi,WG and increased FCR(P=0.001)than low BCAA.However,BCAA levels had no effect(P>0.05)on these measurements in HCP-diets.High NE increased(P<0.001)NEi and decreased(P<0.001)FCR compared to low NE in the HCP-diets.However,the NE effect on both measurements did not differ(P>0.05)in RP-diets.These results indicate that increasing BCAA levels beyond the recommended amounts in RP-diets impairs energy utilization,leading to poor performance.
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.
文摘Insufficient supply, high prices and competition with the human food and biofuel industries means there is a continuous demand for alternative energy sources for poultry. As a result, cassava is becoming an increasingly important ingredient in poultry diets, largely due to its high availability. Efficient use of cassava products has been shown to reduce feed costs of poultry production. The utilisation of cassava is,however, limited by a number of factors, including its high fibre and low energy content and the presence of anti-nutritional factors, primarily hydrocyanic acid(HCN). With correct processing the inclusion level of cassava in poultry diets could be increased. Extensive research has been conducted on cassava products for poultry, but there is still a lack of consistency amongst the measured nutritive values for cassava and its products, hence variation exists in results from poultry studies. This paper reviews the nutrient composition of cassava products and its value as an alternative energy source in poultry diets.
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Poultry production has undergone a substantial increase compared to the livestock industries since 1970.However, the industry worldwide is now facing challenges with the removal of in-feed antibiotics completely or gradually, as the once well-controlled poultry diseases have re-emerged to cause tremendous loss of production. Necrotic enteritis(NE) is one of the most important diseases which costs the industry over two billion dollars annually. In this paper, we review the progress on the etiology of NE and its control through dietary modifications, pre-and probiotics, short chain fatty acids, and vaccination. The other likely measures resulted in the most advances in the toxin characterization are also discussed. Vaccine strategies may have greater potential for the control of NE mainly due to clearer etiology of NE having been elucidated in recent years with the identification of necrotic enteritis toxin B-like(NetB) toxin. Therefore, the use of alternatives to in-feed antibiotics with a better understanding of the relationship between nutrition and NE, and limiting exposure to infectious agents through biosecurity and vaccination, might be a tool to reduce the incidence of NE and to improve gut health in the absence of in-feed antibiotics. More importantly, the combinations of different measures may achieve greater protection of birds against the disease. Among all the alternatives investigated, prebiotics, organic acids and vaccination have shown improved gastrointestinal health and thus, have potential for the control of NE.
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.
文摘Different energy systems have been proposed for energy evaluation of feeds for domestic animals.The oldest and most commonly used systems take into account the fecal energy loss to obtain digestible energy(DE),and fecal,urinary and fermentation gases energy losses to calculate metabolizable energy(ME).In the case of ruminants and pigs,the net energy(NE)system,which takes into account the heat increment associated with the metabolic utilization of ME,has progressively replaced the DE and ME systems over the last 50 years.For poultry,apparent ME(AME)is used exclusively and NE is not yet used widely.The present paper considers some important methodological points for measuring NE in poultry feeds and summarizes the available knowledge on NE systems for poultry.NE prediction equations based on a common analysis of three recent studies representing a total of 50 complete and balanced diets fed to broilers are proposed;these equations including the AME content and easily available chemical indicators have been validated on another set of 30 diets.The equations are applicable to both ingredients and complete diets.They rely primarily on an accurate and reliable AME value which then represents the first limiting predictor of NE value.Our analysis indicates that NE would be a better predictor of broiler performance than AME and that the hierarchy between feeds is dependent on the energy system with a higher energy value for fat and a lower energy value for protein in an NE system.Practical considerations for implementing such an NE system from the commonly used AME or AMEn(AME adjusted for zero nitrogen balance)systems are presented.In conclusion,there is sufficient information to allow the implementation of the NE concept in order to improve the accuracy of feed formulation in poultry.
文摘An experiment was conducted to explore the effects of digestible amino acid(dAA)concentrations and supplemental protease on live performance and energy partitioning in broilers.Ross 308 male broilers(n?288)were distributed into 24 floor pens and offered 1 of 4 dietary treatments with 6 replicates from 1 to 35 d of age.Dietary treatments consisted of a 2×2 factorial arrangement with dAA concentrations(standard and reduced[34 g/kg below standard])and supplemental protease(without or with)as the main factors.At 1,15,28,and 35 d of age,feed and broilerswereweighed to determine live performance.From20 to 23 d of age,a total of 32 birds(2 birds/chamber,4 replicates)were placed in closed-calorimeter chambers to determine respiratory exchange(heat production,HP),apparent metabolisable energy(AME),retained energy(RE),and net energy(NE).From 29 to 35 d of age,supplemental protease in the reduced-dAA diet decreased broiler feed conversion ratio(FCR)by 5.6 points,whereas protease supplementation in the standard-dAA diet increased FCR by 5.8 points.The indirect calorimetry assay revealed that supplemental protease decreased(P<0.05)the heat increment of feed(HIF)by 0.22 MJ/kg.Also,from 20 to 23 d of age,broilers offered the reduced-dAA diet with supplemental protease had a higher daily body weight gain(BWG)(t10.4%),N intake(t7.1%),and N retention(t8.2%)than those offered the standard-dAA with supplemental protease.Broilers offered the reduced-dAA without supplemental protease exhibited a 3.6%higher AME-to-crude protein(CP)ratio than those offered other treatments.Protease supplementation in the standard-and reduced-dAA diets resulted in 2.7%and 5.6%lower AME intake-to-N retention ratios,respectively,compared with the unsupplemented controls.Reduced-dAA increased(P<0.05)AME intake(t4.8%),RE(t9.8%),NE intake(t5.8%),NE intake-to-CP ratio(t3.0%),and RE fat-to-RE ratio(t8.6%).Protease supplementation increased(P<0.05)respiratory quotient(t1.2%)and N retention-to-N intake ratio(t2.2%),NE-to-AME ratio(t1.9%),and reduced HP(3.6%),heat increment(7.4%),and NE intake-to-N retention(2.5%).In conclusion,protease positively affected FCR and energy partitioning in broilers;responses were most apparent in diets with reduced-dAA concentrations.
文摘A total of 294 one-day-old Cobb broiler chickens were used to investigate the effects of four Lactobacillus strains on gut microbial profile and production performance. The six dietary treatments, each with 7 replicates were: 1) basal diet(negative control), 2) one of four strains of Lactobacillus(tentatively identified as Lactobacillus johnsonii, Lactobacillus crispatus, Lactobacillus salivarius and an unidentified Lactobacillus sp.) and 3) basal diet with added zinc-bacitracin(ZnB, 50 mg/kg). Results showed that the addition of probiotic Lactobacillus spp. to the feed did not significantly improve weight gain, feed intake and feed conversion rate(FCR) of broiler chickens raised in cages during the 6-week experimental period,but tended to increase the number of total anaerobic bacteria in the ileum and caeca, and the number of lactic acid bacteria and lactobacilli in the caeca; and to significantly increase the small intestinal weight(jejunum and ileum). Furthermore, all 4 probiotics tended to reduce the number of Enterobacteria in the ileum, compared with the control treatments. The probiotics did not affect the p H and the concentrations of short chain fatty acids(SCFA) and lactic acid in both the ileum and caeca.
基金The authors thank BASF SE for supporting this study,Eimeria Pty Ltd.for providing Eimeria,and Professor Robert Moore for providing Clostridium perfringens EHE-18 strain.
文摘The present study investigated whether supplementing fibre-degrading enzymes can ameliorate the severity of subclinical necrotic enteritis(NE)in broiler chickens offered wheat-or maize-based diets.A total of 1,544 mixed-sex broiler chickens were assigned to 16 experimental treatments as a 2×2×4 factorial arrangement of treatments.The factors were the following:NE challenge,yes or no;diet type,wheat-or maize-based;and enzyme supplementation,control(no enzyme),family 10 xylanase(XYN10),family 11 xylanase(XYN11)or b-mannanase(MAN).Each treatment was replicated 6 times,with 16 birds per replicate pen.A three-way challenge×diet type×enzyme interaction occurred for body weight at 21 d of age(P=0.025)and overall feed conversion ratio(P=0.001).In the non-challenged birds fed the wheat-based diet,supplementing MAN increased d 21 body weight compared to the control.In challenged birds fed the maize-based diet,supplemental XYN11 impeded body weight and overall FCR compared to the control.Birds offered the maize-based diet presented heavier relative gizzard weights at both 16 and 21 d of age(P<0.001)and reduced liveability(P=0.046)compared to those fed the wheatbased diet.Enzyme supplementation reduced ileal and jejunal digesta viscosity at 16 d of age only in birds fed the wheat-based diet(P<0.001).XYN11 increased ileal digesta viscosity in birds fed the maizebased diet,and MAN reduced it in birds fed the wheat-based diet at 21 d of age(P=0.030).Supplementing XYN11 improved ileal soluble non-starch polysaccharides(NSP)digestibility in birds fed the wheat-based diet compared to non-supplemented birds(P<0.001).Birds fed the wheat-based diet displayed a higher abundance of Bifidobacterium,Lactobacillus and Enterobacteriaceae and butyric acid in the caeca at 16 d of age compared to birds fed the maize-based diet(P<0.05).In conclusion,supplemental XYN11 exacerbated the negative impact of NE on growth performance in birds fed the maizebased diet.Supplementing wheat-based diets with fibre-degrading enzymes ameliorates production losses induced by NE.
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.
