Six hundred and forty-five healthy Roman laying hens of 375 days of age were randomly divided into five groups,each included three replicates of 43 layers.
英
美
- 选 375日龄健康的罗曼蛋鸡 6 4 5羽 ,随机分为 5组 ,每组设 3个重复 ,每重复 4 3羽。