Standardized ileal digestibility coefficients(SIDC)of nitrogen(N)and amino acids(AA)in two protein sources(soybean meal[SBM]and canola meal[CM])were investigated at six broiler ages(d 7,14,21,28,35,and 42).Two assay d...Standardized ileal digestibility coefficients(SIDC)of nitrogen(N)and amino acids(AA)in two protein sources(soybean meal[SBM]and canola meal[CM])were investigated at six broiler ages(d 7,14,21,28,35,and 42).Two assay diets were formulated to contain either SBM(413 g/kg)or CM(553 g/kg)as the sole dietary AA source.Titanium dioxide(5 g/kg)was added as an indigestible marker.A total of 696 male broilers at 1 d old were allotted to 12 replicate cages per age group.Each assay diet was offered to birds for 4 d prior to the ileal digesta collection on d 7(14 birds/cage),14(12 birds/cage),21(10 birds/cage),28(8 birds/cage),35(8 birds/cage)and 42(6 birds/cage),respectively.The apparent digestibility coefficients were standardized using age-specific basal endogenous AA flows.In the SBM group,though the SIDC of N tended to be influenced(quadratic;P=0.075)by age,no linear or quadratic response of age effect was observed on the average SIDC of indispensable(IAA)and total AA(TAA).An age effect(quadratic;P<0.05)was observed on the average SIDC of dispensable AA(DAA)in SBM with the highest value recorded at d 7,followed by a decrease from d 14 to 28,which increased beyond d 35.The SIDC of some individual AA(Arg,Thr,Trp,Cys,Pro)were affected(P<0.05 or P<0.001)in a quadratic manner by age.In the CM,the SIDC of N,average SIDC of IAA,DAA and TAA were influenced(quadratic;P<0.05 or P<0.001)by age.The SIDC of N and average SIDC of DAA and TAA were higher from d 7 to 14,declined at d 21,and then increased beyond d 28.The average SIDC of IAA was low between d 7 and 28 and increased thereafter.The SIDC of individual AA were affected(linear or quadratic;P<0.05 or P<0.001)by different magnitudes by age.The age influence on the SIDC AA was variable,depending on the protein source and AA.The results demonstrate that age-specific SIDC AA data might need consideration in broiler feed formulations.展开更多
The primary objective of this study was to investigate the influence of high and low inclusions of nonbound amino acid(NBAA)in standard and reduced-crude protein(CP),wheat-based diets on growth performance in broiler ...The primary objective of this study was to investigate the influence of high and low inclusions of nonbound amino acid(NBAA)in standard and reduced-crude protein(CP),wheat-based diets on growth performance in broiler chickens.Dietary treatments were formulated to either 210 or 180 g/kg CP.The210 g/kg CP diets contained either 12.1 or 21.1 g/kg NBAA and 180 g/kg CP diets contained either 44.0 or55.5 g/kg NBAA.The formulations also generated different dietary starch:protein ratios which impacted on starch-protein digestive dynamics.Each of the four dietary treatments were offered to 7 replicates of15 birds housed in floor pens from 14 to 35 days post-hatch or a total of 420 male Ross 308 chickens.Growth performance,relative abdominal fat-pad weights,breast muscle and leg shank yields were determined.Ileal starch and protein(N)digestibility coefficients,disappearance rates and starch:protein disappearance rate ratios were defined.Apparent ileal digestibility coefficients and disappearance rates of 16 amino acids were determined at 35 days post-hatch and free concentrations of 20 amino acids in systemic plasma were determined at 34 days post-hatch.The transition from 210 to 180 g/kg CP diets depressed weight gain by 11.3%(1742 versus 1964 g/bird)and FCR by 10.4%(1.606 versus 1.455),although both parameters were subject to treatment interactions.The treatment interaction(P<0.001)observed for FCR was because high NBAA inclusions significantly improved FCR by 4.17%(1.424 versus1.486)in birds offered 210 g/kg CP diets,but significantly depressed FCR by 3.36%(1.632 versus 1.579)in180 g/kg CP diets.A quadratic relationship(r=0.860;P<0.001)between dietary NBAA inclusions and FCR was detected,which indicated that when NBAA inclusions exceed 18.5 g/kg efficiency of feed conversion deteriorated.However,a multiple linear regression(r=0.913;P<0.001)was detected for FCR where both NBAA inclusions and analysed dietary starch:protein ratios were significantly(P<0.001)related to FCR.This relationship indicates that growth performance of broiler chickens offered wheatbased diets is strongly influenced by dietary NBAA inclusions coupled with dietary starch:protein ratios and consideration is given to the possible underlying mechanisms.展开更多
The use of reduced protein diets in broiler chicken production provides potential benefits for performance and environmental footprint of production. The effectiveness of β-Mannanase supplementation in wheat and soy ...The use of reduced protein diets in broiler chicken production provides potential benefits for performance and environmental footprint of production. The effectiveness of β-Mannanase supplementation in wheat and soy based standard protein(SP) and reduced protein(RP) diets was tested for growth performance, nutrient utilisation and selected intestinal gene expression of broiler chickens. In a 2 × 2factorial arrangement of treatments, two main factors included dietary protein(standard and reduced protein) and β-Mannanase supplementation(with or without). All diets contained phytase and carbohydrases(xylanase and glucanase). A total of 480 Ross 308 male off-sex day-old chickens were assigned to the four experimental diets in a 35-d study. Each diet was replicated 12 times with 10 birds per replicate. Using an additional 160 birds, separate apparent metabolizable energy(AME) and nutrient digestibility assays were undertaken for the 4 experimental diets from d 21 to 24 of age. Selected genes involved in gut integrity, inflammation and immune response were quantified using quantitative PCR assays. There was no interaction between β-Mannanase and dietary protein for any of the studied parameters except ileal viscosity. Enzyme had no effect on feed intake but tended to increase body weight gain(BWG) from d 0 to 35 of age(P = 0.079). Birds fed RP diet consumed more feed when assessed from d 0 to 35 of age(P = 0.029). At the same time, β-Mannanase tended to reduce feed conversion ratio independent of dietary protein(P = 0.069). β-Mannanase reduced ileal viscosity of the birds fed RP diet(P < 0.001). Reducing dietary protein increased nitrogen retention, nitrogen digestibility coefficient and digestibility coefficients of 11 amino acids(P < 0.001). β-Mannanase significantly improved digestibility coefficients of nitrogen and Arg, Gly, Thr, Lys, and Ile(P < 0.05). Dietary treatments had no effect on AME or gene expression of selected tight junction proteins, interleukin-10, interleukin-1β, mucin-2 and nuclear factor-kappa B. In conclusion, supplementation of β-Mannanase tended to improve feed efficiency and increased nutrient digestibility of broilers fed wheat-based diets independent of a moderate reduction in dietary protein. Complementary mode of actions of β-Mannanase for intestinal health requires further investigation.展开更多
The objective of this study was to investigate the effects of dietary crude protein(CP)concentrations,grain types and arginine:lysine ratios on performance parameters of broiler chickens.The 2×2×2factorial a...The objective of this study was to investigate the effects of dietary crude protein(CP)concentrations,grain types and arginine:lysine ratios on performance parameters of broiler chickens.The 2×2×2factorial array of dietary treatments harnessed two CP concentrations(210 and 170 g/kg),two feed grains(wheat and sorghum),and two arginine:lysine ratios(104 and 110).Each dietary treatment was offered to 7 replicates of 14 birds per floor pen,a total of 784 off-sex male,Ross 308 broilers,from 14 to 35 d post-hatch.The dietary CP reduction compromised weight gain by 10.0%(2078 versus 2310 g/bird)as a main effect and FCR by 7.51%(1.474 versus 1.371),subject to an interaction.In a three-way interaction(P=0.008),expanded arginine:lysine ratios improved FCR by 2.30%in 170 g/kg CP,sorghum-based diets but compromised FCR by 2.12%in corresponding wheat-based diets.Sorghum was the more suitable feed grain in reduced-CP diets as sorghum generated significant advantages in weight gain of 7.59%(2154versus 2002 g/kg)and FCR of 6.94%(1.421 versus 1.527)in birds offered 170 g/kg CP diets.Both dietary CP and feed grain generated significant and divergent impacts in apparent ileal digestibility coefficients for the majority of 16 assessed amino acids.Dietary CP reductions increased non-bound amino acid inclusions(NBAA)in wheat-based diets(48.96 versus 9.80 g/kg)to a greater extent than sorghum-based diets(35.3 versus 9.50 g/kg)and increasing dietary NBAA inclusions were linearly associated with compromised weight gain(r=-0.834;P<0.001)and FCR(r=0.862;P<0.001).Increasing ratios of free arginine to lysine plasma concentrations were linearly(r=-0.466;P=0.004)related to improvements in FCR.The implications of the observed outcomes are discussed and possible explanations are advanced.展开更多
The objective of this review is to identify the shortfalls of wheat-based,crude protein(CP)-reduced diets for broiler chickens as wheat is inferior to maize in this context but to inconsistent extents.Inherent factors...The objective of this review is to identify the shortfalls of wheat-based,crude protein(CP)-reduced diets for broiler chickens as wheat is inferior to maize in this context but to inconsistent extents.Inherent factors in wheat may be compromising gut integrity;these include soluble non-starch polysaccharides(NSP),amylase trypsin inhibitors(ATI)and gluten.Soluble NSP in wheat induce increased gut viscosities,which can lead to compromised gut integrity,which is not entirely ameliorated by NSP-degrading feed enzymes.Wheat ATI probably compromise gut integrity and may also have the capacity to increase endogenous amino acid flows and decrease apparent starch and protein digestibilities.Gluten inclusions of 20 g/kg in a maize-soy diet depressed weight gain and feed intake and higher gluten inclusions have been shown to activate inflammatory cytokine-related genes in broiler chickens.Further research is required,perhaps particularly in relation to wheat ATI.The protein content of wheat is typically higher than maize;importantly,this results in higher inclusions of non-bound amino acids in CP-reduced broiler diets.These higher inclusions could trigger post-enteral amino acid imbalances,leading to the deamination of surplus amino acids and the generation of ammonia(NH3)which,if not adequately detoxified,results in compromised growth performance from NH3overload.Thus,alternatives to nonbound amino acids to meet amino acid requirements in birds offered CP-reduced,wheat-based diets merit evaluation.The digestion of wheat starch is more rapid than that of maize starch which may be a disadvantage as the provision of some slowly digestible starch in broiler diets may enhance performance.Alternatively,slowly digestible starch may result in more de novo lipogenesis.Therefore,it may prove instructive to evaluate CP-reduced diets based on maize-wheat and/or sorghum-wheat blends rather than entirely wheat.This would reduce non-bound amino acid inclusions by lowering dietary CP derived from feed grains and may enhance starch digestive dynamics by retarding starch digestion rates.Also,the use of biomarkers to monitor gut integrity in broiler chickens is examined where calprotectin,ovotransferrin and possibly citrulline appear to hold promise,but their validation requires further research.展开更多
基金“AgriFutures Australia Chicken Meat Program”for funding the project(grant number PRJ011835)
文摘Standardized ileal digestibility coefficients(SIDC)of nitrogen(N)and amino acids(AA)in two protein sources(soybean meal[SBM]and canola meal[CM])were investigated at six broiler ages(d 7,14,21,28,35,and 42).Two assay diets were formulated to contain either SBM(413 g/kg)or CM(553 g/kg)as the sole dietary AA source.Titanium dioxide(5 g/kg)was added as an indigestible marker.A total of 696 male broilers at 1 d old were allotted to 12 replicate cages per age group.Each assay diet was offered to birds for 4 d prior to the ileal digesta collection on d 7(14 birds/cage),14(12 birds/cage),21(10 birds/cage),28(8 birds/cage),35(8 birds/cage)and 42(6 birds/cage),respectively.The apparent digestibility coefficients were standardized using age-specific basal endogenous AA flows.In the SBM group,though the SIDC of N tended to be influenced(quadratic;P=0.075)by age,no linear or quadratic response of age effect was observed on the average SIDC of indispensable(IAA)and total AA(TAA).An age effect(quadratic;P<0.05)was observed on the average SIDC of dispensable AA(DAA)in SBM with the highest value recorded at d 7,followed by a decrease from d 14 to 28,which increased beyond d 35.The SIDC of some individual AA(Arg,Thr,Trp,Cys,Pro)were affected(P<0.05 or P<0.001)in a quadratic manner by age.In the CM,the SIDC of N,average SIDC of IAA,DAA and TAA were influenced(quadratic;P<0.05 or P<0.001)by age.The SIDC of N and average SIDC of DAA and TAA were higher from d 7 to 14,declined at d 21,and then increased beyond d 28.The average SIDC of IAA was low between d 7 and 28 and increased thereafter.The SIDC of individual AA were affected(linear or quadratic;P<0.05 or P<0.001)by different magnitudes by age.The age influence on the SIDC AA was variable,depending on the protein source and AA.The results demonstrate that age-specific SIDC AA data might need consideration in broiler feed formulations.
基金AgriFutures Chicken-meat for funding the project “Optimising amino acid profiles and energy in reducedprotein diets”(PRJ010520)the financial support provided by Australian Government Research Training Program Scholarship (RTP) received by PhD student Mr Shemil Macelline
文摘The primary objective of this study was to investigate the influence of high and low inclusions of nonbound amino acid(NBAA)in standard and reduced-crude protein(CP),wheat-based diets on growth performance in broiler chickens.Dietary treatments were formulated to either 210 or 180 g/kg CP.The210 g/kg CP diets contained either 12.1 or 21.1 g/kg NBAA and 180 g/kg CP diets contained either 44.0 or55.5 g/kg NBAA.The formulations also generated different dietary starch:protein ratios which impacted on starch-protein digestive dynamics.Each of the four dietary treatments were offered to 7 replicates of15 birds housed in floor pens from 14 to 35 days post-hatch or a total of 420 male Ross 308 chickens.Growth performance,relative abdominal fat-pad weights,breast muscle and leg shank yields were determined.Ileal starch and protein(N)digestibility coefficients,disappearance rates and starch:protein disappearance rate ratios were defined.Apparent ileal digestibility coefficients and disappearance rates of 16 amino acids were determined at 35 days post-hatch and free concentrations of 20 amino acids in systemic plasma were determined at 34 days post-hatch.The transition from 210 to 180 g/kg CP diets depressed weight gain by 11.3%(1742 versus 1964 g/bird)and FCR by 10.4%(1.606 versus 1.455),although both parameters were subject to treatment interactions.The treatment interaction(P<0.001)observed for FCR was because high NBAA inclusions significantly improved FCR by 4.17%(1.424 versus1.486)in birds offered 210 g/kg CP diets,but significantly depressed FCR by 3.36%(1.632 versus 1.579)in180 g/kg CP diets.A quadratic relationship(r=0.860;P<0.001)between dietary NBAA inclusions and FCR was detected,which indicated that when NBAA inclusions exceed 18.5 g/kg efficiency of feed conversion deteriorated.However,a multiple linear regression(r=0.913;P<0.001)was detected for FCR where both NBAA inclusions and analysed dietary starch:protein ratios were significantly(P<0.001)related to FCR.This relationship indicates that growth performance of broiler chickens offered wheatbased diets is strongly influenced by dietary NBAA inclusions coupled with dietary starch:protein ratios and consideration is given to the possible underlying mechanisms.
文摘The use of reduced protein diets in broiler chicken production provides potential benefits for performance and environmental footprint of production. The effectiveness of β-Mannanase supplementation in wheat and soy based standard protein(SP) and reduced protein(RP) diets was tested for growth performance, nutrient utilisation and selected intestinal gene expression of broiler chickens. In a 2 × 2factorial arrangement of treatments, two main factors included dietary protein(standard and reduced protein) and β-Mannanase supplementation(with or without). All diets contained phytase and carbohydrases(xylanase and glucanase). A total of 480 Ross 308 male off-sex day-old chickens were assigned to the four experimental diets in a 35-d study. Each diet was replicated 12 times with 10 birds per replicate. Using an additional 160 birds, separate apparent metabolizable energy(AME) and nutrient digestibility assays were undertaken for the 4 experimental diets from d 21 to 24 of age. Selected genes involved in gut integrity, inflammation and immune response were quantified using quantitative PCR assays. There was no interaction between β-Mannanase and dietary protein for any of the studied parameters except ileal viscosity. Enzyme had no effect on feed intake but tended to increase body weight gain(BWG) from d 0 to 35 of age(P = 0.079). Birds fed RP diet consumed more feed when assessed from d 0 to 35 of age(P = 0.029). At the same time, β-Mannanase tended to reduce feed conversion ratio independent of dietary protein(P = 0.069). β-Mannanase reduced ileal viscosity of the birds fed RP diet(P < 0.001). Reducing dietary protein increased nitrogen retention, nitrogen digestibility coefficient and digestibility coefficients of 11 amino acids(P < 0.001). β-Mannanase significantly improved digestibility coefficients of nitrogen and Arg, Gly, Thr, Lys, and Ile(P < 0.05). Dietary treatments had no effect on AME or gene expression of selected tight junction proteins, interleukin-10, interleukin-1β, mucin-2 and nuclear factor-kappa B. In conclusion, supplementation of β-Mannanase tended to improve feed efficiency and increased nutrient digestibility of broilers fed wheat-based diets independent of a moderate reduction in dietary protein. Complementary mode of actions of β-Mannanase for intestinal health requires further investigation.
基金AgriFutures Chicken-meat for funding the project“Optimising amino acid profiles and energy in reducedprotein diets”(PRJ-010520)financial support provided by Australian Government Research Training Program Scholarship(RTP)received by PhD candidate Mr Shemil Macelline.
文摘The objective of this study was to investigate the effects of dietary crude protein(CP)concentrations,grain types and arginine:lysine ratios on performance parameters of broiler chickens.The 2×2×2factorial array of dietary treatments harnessed two CP concentrations(210 and 170 g/kg),two feed grains(wheat and sorghum),and two arginine:lysine ratios(104 and 110).Each dietary treatment was offered to 7 replicates of 14 birds per floor pen,a total of 784 off-sex male,Ross 308 broilers,from 14 to 35 d post-hatch.The dietary CP reduction compromised weight gain by 10.0%(2078 versus 2310 g/bird)as a main effect and FCR by 7.51%(1.474 versus 1.371),subject to an interaction.In a three-way interaction(P=0.008),expanded arginine:lysine ratios improved FCR by 2.30%in 170 g/kg CP,sorghum-based diets but compromised FCR by 2.12%in corresponding wheat-based diets.Sorghum was the more suitable feed grain in reduced-CP diets as sorghum generated significant advantages in weight gain of 7.59%(2154versus 2002 g/kg)and FCR of 6.94%(1.421 versus 1.527)in birds offered 170 g/kg CP diets.Both dietary CP and feed grain generated significant and divergent impacts in apparent ileal digestibility coefficients for the majority of 16 assessed amino acids.Dietary CP reductions increased non-bound amino acid inclusions(NBAA)in wheat-based diets(48.96 versus 9.80 g/kg)to a greater extent than sorghum-based diets(35.3 versus 9.50 g/kg)and increasing dietary NBAA inclusions were linearly associated with compromised weight gain(r=-0.834;P<0.001)and FCR(r=0.862;P<0.001).Increasing ratios of free arginine to lysine plasma concentrations were linearly(r=-0.466;P=0.004)related to improvements in FCR.The implications of the observed outcomes are discussed and possible explanations are advanced.
文摘The objective of this review is to identify the shortfalls of wheat-based,crude protein(CP)-reduced diets for broiler chickens as wheat is inferior to maize in this context but to inconsistent extents.Inherent factors in wheat may be compromising gut integrity;these include soluble non-starch polysaccharides(NSP),amylase trypsin inhibitors(ATI)and gluten.Soluble NSP in wheat induce increased gut viscosities,which can lead to compromised gut integrity,which is not entirely ameliorated by NSP-degrading feed enzymes.Wheat ATI probably compromise gut integrity and may also have the capacity to increase endogenous amino acid flows and decrease apparent starch and protein digestibilities.Gluten inclusions of 20 g/kg in a maize-soy diet depressed weight gain and feed intake and higher gluten inclusions have been shown to activate inflammatory cytokine-related genes in broiler chickens.Further research is required,perhaps particularly in relation to wheat ATI.The protein content of wheat is typically higher than maize;importantly,this results in higher inclusions of non-bound amino acids in CP-reduced broiler diets.These higher inclusions could trigger post-enteral amino acid imbalances,leading to the deamination of surplus amino acids and the generation of ammonia(NH3)which,if not adequately detoxified,results in compromised growth performance from NH3overload.Thus,alternatives to nonbound amino acids to meet amino acid requirements in birds offered CP-reduced,wheat-based diets merit evaluation.The digestion of wheat starch is more rapid than that of maize starch which may be a disadvantage as the provision of some slowly digestible starch in broiler diets may enhance performance.Alternatively,slowly digestible starch may result in more de novo lipogenesis.Therefore,it may prove instructive to evaluate CP-reduced diets based on maize-wheat and/or sorghum-wheat blends rather than entirely wheat.This would reduce non-bound amino acid inclusions by lowering dietary CP derived from feed grains and may enhance starch digestive dynamics by retarding starch digestion rates.Also,the use of biomarkers to monitor gut integrity in broiler chickens is examined where calprotectin,ovotransferrin and possibly citrulline appear to hold promise,but their validation requires further research.
