日粮代谢能水平对“京红1号”蛋种鸡育成期生长性能及后续生产性能的影响

试验旨在研究日粮不同代谢能水平对"京红1号"蛋种鸡育成期生长性能及后续生产性能的影响。试验选用9周龄"京红1号"蛋种鸡1 260只,随机分为4个处理,每处理5个重复,每重复63只鸡,4个处理组日粮代谢能水平分别为11.30、11.50、11.70、11.90 MJ/kg,粗蛋白水平均为15.5%,试验期为4周。饲养试验结束后育成鸡转入产蛋舍,4个处理组饲喂同一种日粮(代谢能水平为11.51 MJ/kg、粗蛋白水平为16.4%),从见蛋开始跟踪记录鸡只的生产性能(10 d)。结果表明:随着日粮代谢能水平的增加,蛋鸡平均体重、日增重和胫长均显著增加(P0.05);耗料增重比和血浆尿素氮水平显著降低(P0.05);11.90 MJ/kg处理组平均体重、日增重和胫长最高,耗料增重比和血浆尿素氮水平最低;11.70 MJ/kg处理组的生长性能次之,后续的生产性能表现最好,其见蛋日龄最早,初始产蛋率最高。综合育成期生长性能和后续生产性能结果,"京红1号"蛋种鸡育成期(9~13周龄)代谢能水平在11.70 MJ/kg较为适宜。

Effects of Dietary Metabolizable Energy Levels on Growth Performance and Subsequent Production Performance of Jinghong Layers in Finishing Period(9-13 week)

The experiment was conducted to investigate the effect of dietary metabolizable energy(ME) levels on growth performance and subsequent production performance of Jinghong layers in finishing period. A total of 1 260 9-weekold Jinghong layers were randomly assigned to 4 treatments(ME 11.30, 11.50, 11.70 and 11.90 MJ/kg, CP 15.5%) with 5 replicates of 63 birds per replicate. The experiment lasted for four weeks. After the feeding experiment, the layers were transferred to the laying hens experiment, and all layers were fed with the same diet(ME11.51 MJ/kg, CP16.4%). Growth performances and subsequent production performances were evaluated. The results showed that with the increase of dietary ME, body weight, average daily gain and shank length significantly increased(P<0.05), whereas the feed/gain ratio and plasma urea nitrogen significantly decreased(P<0.05).The treatment of ME 11.90 MJ/kg performed best with the highest body weight, average daily gain and shank length, as well as the lowest feed/gain ratio and plasma urea nitrogen. Growth performance of treatment ME 11.70 MJ/kg took the second place, but the treatment performed well in subsequent laying performance with opening day coming the earliest and the highest initial production rate. Considering the growth performance and subsequent production performance, the optimal energy level in finishing period(9-13 week) of Jinghong layers was recommended to be11.70 MJ/kg.