摘要
通过研究日粮中色氨酸水平对肉仔鸡生长性能、氮平衡及血清尿素氮含量的影响，探讨不同生长阶段不同性别肉仔鸡色氨酸的需求参数。试验期８周。结果表明：日粮中色氨酸达到适宜水平时，肉鸡的平均日增重增加（Ｐ＜０．０５）、料肉比降低（Ｐ＜０．０５）、血清尿素氮（ＢＵＮ）含量下降（Ｐ＜０．０５）；色氨酸水平过高则不能继续改善其生产性能，甚至造成负效应。在３～６周龄及６～８周龄阶段，公鸡色氨酸需求参数高于母鸡。日粮色氨酸水平对肉鸡的氮沉积率无显著影响（Ｐ＞０．０５），不同性别肉鸡的氮沉积率无显著差别（Ｐ＞０．０５）。根据各项指标的测定结果，建议在０～３周龄，肉鸡色氨酸需求参数为０．２１％；在３～６周龄，公鸡色氨酸需求参数为０．２０％，母鸡为０．１８％；在６～８周龄阶段，公鸡色氨酸需求参数为０．１８％，母鸡为０．１６％。采用去盲肠成年种公鸡测定基础日粮（玉米—玉米蛋白粉）中色氨酸的消化率，并计算出不同性别肉鸡可消化色氨酸需求参数。
Studies with broiler type chickens were conducted to determine the minimum tryptophan (Try)requirements for maximum growth,optimum feed efficiency and maximum nitrogen retention coeffeicient for both males and females.Try-deficient diets were based upon corn,corn gluten meal,fish meal,oil and premix.The Try digestibilities of basic diets were determined by Sibbald method.According to the results of growth rate,feed efficiency and N-retention coefficient,we concluded that:the Try requirements of males were larger than the females.During 0 to 21 days,the total Try requirements of both males and females were 0.21%,Apparent digestible(AD) Try requirements were 0.16%,and true digestible (TD) Try requirements were 0.18%.During 22 to 42 days,the total,AD,TD Try requirements of males were 0.20%,0.16%,0.17%,respectively,females were 0.18%,0.14%,0.16%,respectively.During 43 to 56 days,the males requirements were 0.18%,0.15%,0.16%,respectively,females were 0.16%,0.13%,0.14%,respectively.
出处
《动物营养学报》
CAS
CSCD
1999年第2期45-53,共9页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
广东省自然科学基金
