Three groups of 15 day old broiler chicks were separately subjected to noise of 70 dB, 80dB, 90dB, the controlled group was not subjected to noise.

• 供试鸡为 1 0 0只 1 5日龄的 AA鸡 ,把其按交叉分组法分为四组 ( 1个对照组和 3个试验组 ) ,对照组不给噪声 ,试验组 ( A、B、C)组分别给予 70分贝、80分贝、90分贝的噪声 ,试验期为 30天。