日粮粗蛋白质水平及添加尿素对肉鸡生产性能的影响

将288羽21日龄艾维茵肉鸡分为6组,设计16%,18%和20%粗蛋白质(CP)不同水平,及其分别添加1g/kg尿素(U)共构成6组日粮,随机分配给6组肉鸡,观测不同处理对肉鸡生产性能及血液生化指标的影响。结果表明:(1)随日粮CP水平提高,肉鸡采食量下降,16%CP及16%CP+U组显著高于其他组(P<0.05);全期平均日增重以16%CP+U及18%CP组最高(P<0.05);全期料肉比以16%CP和18%CP+U组最高(P<0.05)。(2)随日粮CP水平提高,肉鸡腹脂率下降,20%CP及20%CP+U组显著低于其他组(P<0.05);胸肉率18%CP组显著高于16%CP,16%CP+U及20%CP+U组(P<0.05);添加尿素腹脂率趋于降低(P>0.05);20%CP+U组胸肉率显著降低(P<0.05)。(3)CP水平及添加尿素显著影响血清尿素氮(BUN)及血清总蛋白(BTP)。说明在本试验能量水平及氨基酸模式下,低蛋白质日粮(16%)加1g/kg尿素可使肉鸡获得较好的生产性能。

Effect of dietary protein content and supplementation of urea on broiler's performance

To investigate the effect of dietary protein content and supplementation of urea on the performance and blood biochemical index of broiler,288 Avin commercial broilers aged 21 d were divided into 6 groups.The 3 basal diets with 16%,18% and 20% crude protein (CP) and the same content of energy and main essential amino acids were designed.The other 3 diets were formed by supplementation of 1 g/kg urea (U) in diets of the 3 basal diets.The 6 diets were assigned to 6 groups at random.The results showed:1.With the increase of CP,feed intake (FI) decreased,FI of 16% CP and 16% CP+U were higher than that of other groups significantly (P<0.05);Weight gain of 16% CP+U and 18% CP were higher than that of other groups significantly (P<0.05);FCR of 16% CP and 18% CP+U were higher than that of other groups significantly (P<0.05);2.With CP increasing,the abdominal fat decreased.The abdominal fat rate of 20% CP and 20% CP+U were lower than other groups (P<0.05);The breast meat rate of 18% CP was higher than that of 16% CP and 16% CP+U and 20% CP+U (P<0.05).Supplementation urea in diets has the trend of lowering the abdominal fat rate(P>0.05).Diet with 20% CP plus 1 g/kg urea lowered the breast meat rate significantly (P<0.05);3.CP in diets and supplementation of urea affect BUN and BTP of broilers significantly.The conclusion is:1.Though the requirement of all essential amino acids can meet the needs of broilers,the moderate content of non-essential amino acid are needed in diet.(2.Under) the energy level and amino acid profile of this experiment,the diet with 16% CP will hinder the performance of broilers because of the deficiency of non-essential amino acid,but adding 1 g/kg urea could compensate this deficiency and make broiler achieve better performance.