玉米理化品质及其鸡代谢能的变异研究

试验测定了55个玉米样品的理化指标和鸡代谢能以评定玉米的营养价值变异。将28日龄体重相近的AA肉仔鸡随机分为不同处理组,每组8个重复,每个重复8只鸡。试验包括1个基础日粮组及待测玉米替代组,添加0.4%TiO2作为外源指示剂。收集32～35日龄排泄物,测定玉米样品的AME和AMEn。结果显示,玉米粗脂肪、粗灰分、酸性洗涤纤维和直支比的变异系数分别为10.35%、12.32%、11.33%和13.51%,其余理化指标变异系数在10%以内。玉米AME和AMEn的变异系数分别为5.97%和5.78%,且不同来源玉米代谢能存在显著差异。从相关性分析结果看,玉米代谢能的差异主要由玉米总能、中性洗涤纤维、酸性洗涤纤维和总淀粉含量的差异所致。

Physical and chemical quality of corn and its variation research of metabolizable energy in broilers

Fifty-five corn samples were collected across China and were analysed for their chemical and physical properties.A series of metabolism experiments was conducted to determine the AME and AMEn of these corn samples.For each metabolism experiment,28-day AA broiler chickens were randomly allotted into different treatments consisted of 8 replicates.A corn-soybean meal basal diet and other substitutions(60% of the basal diet + 40% test corn sample selected from different regions) were prepared.TiO2was added into the test diets as indigestive marker,parts of excreta were collected and pooled for each replicate at 32～35 d to determine the AME and AMEn of corns.The results showed that the coefficients of variation of EE,Ash,ADF and(AM/AP) were over 10%,at 10.35%,12.32%,11.33% and 13.51% respectively,but the coefficients of variation of other physical and chemical indexes were less than 10%.The coefficients of variation of AME and AMEn,were 5.97% and 5.78% respectively,and the significant difference exists among metabolizable energy values of corns from different regions.Correlation analysis showed that the variation in metabolizable energy values of corns was resulted from the variation in GE,NDF,ADF and total starch content of corns.