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
This study evaluated the effect of multi-carbohydrase(MC)on energy and nitrogen(N)balance and gene expression in broilers fed diets with different crude protein(CP)contents.The study employed a 2×2 factorial arra...This study evaluated the effect of multi-carbohydrase(MC)on energy and nitrogen(N)balance and gene expression in broilers fed diets with different crude protein(CP)contents.The study employed a 2×2 factorial arrangement of treatments.The factors were presence or absence of MC,and standard(SCP)or low(LCP)dietary CP concentration.A 3-phase feeding program was used,including starter(0 to 7 d),grower(8 to 17 d)and finisher(18 to 28 d)phases.The study was undertaken in closed calorimetry chambers.Each of the 4 dietary treatments was replicated 8 times in total across 2 runs,with 2 birds per replicate(n=64).Data for energy partitioning and N balance were collected from d 25 to 28.On d 28,birds were euthanized to collect muscle and intestinal tissue samples for gene expression.The results showed that the MC increased apparent metabolizable energy(AME,P<0.01)and net energy(NE,P<0.05),and reduced the feed conversion ratio(FCR,P<0.01)in all diets.The proportion of energy retained as fat per total energy retention(REf/RE)was positively correlated with feed AME and NE(r=0.541,P<0.01 and r=0.665,P<0.001,respectively),suggesting that feed energy augmented with increased fat gain.Muscle ATP synthase subunit alpha(ATPSA1W)gene expression had a positive cor-relation with REf/RE and feed NE(r=0.587,P<0.001 and r=0.430,P<0.05,respectively).Similarly,muscle peroxisome proliferator-activated receptor gamma coactivator 1 alpha(PGC-1A)expression was negatively correlated with weight gain and positively correlated with FCR(r-0.451,P<0.05 and r-0.359,P<0.05,respectively).These correlations show that over-expressions of muscle genes related to energy production reduce bird performance.This study demonstrated that MC increase dietary energy utilization,regardless of dietary CP concentration.However,the energy released by the enzymes in-creases feed energy-to-CP ratio,meaning there is excess energy that is then deposited as body fat.This suggests that supplemental MC in broiler feeds is beneficial if diets are formulated to contain marginal energy levels.展开更多
基金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.
基金The authors gratefully acknowledge Adisseo France for financial support of this study.
文摘This study evaluated the effect of multi-carbohydrase(MC)on energy and nitrogen(N)balance and gene expression in broilers fed diets with different crude protein(CP)contents.The study employed a 2×2 factorial arrangement of treatments.The factors were presence or absence of MC,and standard(SCP)or low(LCP)dietary CP concentration.A 3-phase feeding program was used,including starter(0 to 7 d),grower(8 to 17 d)and finisher(18 to 28 d)phases.The study was undertaken in closed calorimetry chambers.Each of the 4 dietary treatments was replicated 8 times in total across 2 runs,with 2 birds per replicate(n=64).Data for energy partitioning and N balance were collected from d 25 to 28.On d 28,birds were euthanized to collect muscle and intestinal tissue samples for gene expression.The results showed that the MC increased apparent metabolizable energy(AME,P<0.01)and net energy(NE,P<0.05),and reduced the feed conversion ratio(FCR,P<0.01)in all diets.The proportion of energy retained as fat per total energy retention(REf/RE)was positively correlated with feed AME and NE(r=0.541,P<0.01 and r=0.665,P<0.001,respectively),suggesting that feed energy augmented with increased fat gain.Muscle ATP synthase subunit alpha(ATPSA1W)gene expression had a positive cor-relation with REf/RE and feed NE(r=0.587,P<0.001 and r=0.430,P<0.05,respectively).Similarly,muscle peroxisome proliferator-activated receptor gamma coactivator 1 alpha(PGC-1A)expression was negatively correlated with weight gain and positively correlated with FCR(r-0.451,P<0.05 and r-0.359,P<0.05,respectively).These correlations show that over-expressions of muscle genes related to energy production reduce bird performance.This study demonstrated that MC increase dietary energy utilization,regardless of dietary CP concentration.However,the energy released by the enzymes in-creases feed energy-to-CP ratio,meaning there is excess energy that is then deposited as body fat.This suggests that supplemental MC in broiler feeds is beneficial if diets are formulated to contain marginal energy levels.
