生物秸秆对肉鸡表观代谢能的影响及替代玉米适宜比例的研究

本试验旨在研究肉鸡对生物秸秆的表观代谢能及其替代玉米的适宜比例.生物秸秆代谢能的测定试验选择24只42日龄健康的爱拔益加(AA)肉鸡,随机分为3个处理,每个处理8只鸡.处理1饲喂含8％生物秸秆的基础饲粮,处理2饲喂以30％的生物秸秆代替基础饲粮中能量饲料和蛋白质饲料的饲粮,处理3采用强饲法进行测定.生物秸秆代替玉米的试验选择150只42日龄健康的AA肉鸡,随机分为5个处理,每个处理5个重复,每个重复6只鸡.对照组饲喂基础饲粮,试验组分别在基础饲粮中用4％、8％、12％生物秸秆代替玉米(代谢能按照差量法计算结果12.46 MJ/kg计)及8％生物秸秆代替玉米(代谢能按照强饲法计算结果5.30 MJ/kg计,添加豆油,使其代谢能水平与对照组相同).结果表明:1)基础饲粮的代谢能为12.63 MJ/kg,采用差量法推算出肉鸡对生物秸秆的表观代谢能为12.46 MJ/kg,而采用套算法和强饲法测定生物秸秆的表观代谢能分别为4.38和5.30 MJ/kg.2)与对照组相比,4％和8％的生物秸秆代替玉米组中性洗涤纤维和酸性洗涤纤维的代谢率显著升高(P＜0.05),而12％的生物秸秆代替玉米组表观能量的代谢率显著降低(P＜0.05).由此得出,套算法和强饲法低估了生物秸秆的表观代谢能,而差量法更能准确反映生物秸秆的表观代谢能；在肉鸡饲粮中生物秸秆可以替代4％ ～8％的玉米.

Biological Corn Stalk: Effects on Apparent Metabolizable Energy and Its Appropriate Substitution Rate for Corn Meal in Broiler Diets

The experiment was conducted to determine the apparent metabolizable energy(AME) of biological corn stalk(BCS) and its appropriate substitution rate for corn meal in broiler diets.Twenty four 42-day-old healthy Arbor Acres(AA) broilers were assigned to 3 groups and 8 broilers in each group.Broilers in group 1 were fed a basal diet with 8% BCS;those in group 2 were fed the basal diet added with 30% BCS to replace the same percentage of energy and protein feedstuffs in the basal diet;those in group 3 were used to measure AME by the superalimentation.To get the appropriate substitution rate of BCS for corn meal in broiler diets,another metabolic experiment was adopted.One hundred and fifty 22-day-old healthy AA broilers were assigned to 5 groups with 5 replicates in each group and 30 broilers in each replicate.The broilers in the control group were fed the basal diet;those in groups 1,2 and 3 were fed the basal diets added with 4%,8% and 12% BCS for replacing the same percentage of corn meal in the basal diet,respectively;those in group 4 were fed the basal diet added with 8% BCS for replacing the same percentage of corn meal in the basal diet under the condition that the metablizable energy(estimated at 5.30 MJ/kg) was adjusted to the same level as the control group by soybean oil addition.The results showed as follows: 1) the AME of the basal diet was 12.63 MJ/kg,so AME of BCS was predicted to be 12.46 MJ/kg by difference method.AME of BCS was 5.30 and 4.38 MJ/kg by superalimentation and substitution method,respectively.2) The metabolic rates of NDF and ADF in groups 1 and 2 were significantly higher than those in the control group(P<0.05),and the energy metabolic rate in group 3 was reduced(P<0.05).It is concluded that the superalimentation and substitution method underestimated AME of BCS,and the AME of BCS predicted by difference method can better reflect the true nutrient values;4% to 8% BCS in broiler diets can replace the same percentage of corn meal for keeping the same nutrient metabolic rates.