The levels of the vitamin A were 3000,6000,12000,24000IU/kg respectvely in the 8 treatments. The results of the Exp.

• 每个温度下的日粮都有4个维生素A浓度，分别为3000IU/kg(2×NRC)、6000IU/kg(4×NRC)、12000IU/kg(8×NRC)和24000IU/kg(16×NRC)，每个日粮处理下设置2个重复。