祖代蛋种鸡的强制换羽试验

将4358只健康的63周龄罗曼褐祖代D系蛋用种鸡依其在舍内原来所处位置分为4组(D1、D2、D3和D4)进行强制换羽。D3和D4两组于断料后的前3天每只每天补饲石粉15g,D1和D2组不补加;恢复正常后喂料D2和D4两组使用预产鸡料lld,转为产蛋期料,D1和D3两组在恢复喂料后第20天直接由育成鸡料转换为产蛋鸡料。结果在断料后产蛋率降低幅度方面的大小顺序为D1、D2、D4、D3;断料期间各组体重降低速度方面无显著差异,但恢复喂料后D4的体重增长速度明显高于其他3组;恢复喂料后第3～6周内平均产蛋率由高到低依次为D2、D4、D3和D1;平均蛋重各组间无显著差异;停料期间及恢复喂料早期的死淘率D3明显低于其他3组,D4次之,D2最高。综合来看,以断料之初补饲3d石粉、恢复喂料期间使用预产鸡料的处理效果最好。

Experimentation with forced molting of grandparent chickens

4358 healthy grandparent D line egg-type breeding chickens(Lohmann Brown) at 63 wk of age were divided into 4 groups (D1 ,D2,D3 and D3) for forced molting. D3 and D4 hens were given 15 g/d per bird of ground stone in the first three days after feed deprivation, and D1 and D2 hens no supplementation. After normalization, D2 and D4 hens were given prelay feed for 11 days, and then switched to laying feed. On day 20 after normal feeding, D1 and D3 hens switched from finisher feed to laying feed directly. As a result, magnitudes of reduction in egg production after feed deprivation were in the order of D1 ,D2,D4 and D3 from big to small. During the period of feed deprivation, there was no significant difference in rate of weight loss for all groups. However, hens in the D4 group gained evidently faster than those in the three other groups after normalization of feeding. Average egg production during 3 - 6 weeks of age went down in the order of D2, D4, D3 and D2. Average egg weight did not differ significantly among the groups. During the periods of feed deprivation and early normalized feeding, D3 hens had an evidently higher mortality rate than the hens in the three other groups, followed by D4 with D2 the highest.