高温条件下大豆黄酮对产蛋前期种鸡产蛋性能和血清甲状腺激素水平的影响

选取 90只 1 55日龄岭南黄肉用种母鸡 ,随机分为 3组 ,每组 30只。其中对照组饲喂基础日粮 ,试验组Ⅰ喂基础日粮 +大豆黄酮 (Da)每千克饲料 3mg ,试验组Ⅱ喂基础日粮 +Da每千克饲料 6mg。预试期为 7d ,试验期 2 5d。各组混养 3只公鸡。采集试验处理前 1d ( 2 2℃ )、处理第 7天 ( 2 3℃ )、 1 1天 ( 30 5℃ )、 1 5天 ( 32 3℃ )的血样 ,测定甲状腺激素 (T3、T4 )水平。结果显示 :①与对照组相比 ,温度为 30 5℃ ,持续 2d ,试验组Ⅰ和Ⅱ的产蛋率分别提高 30 0 %和 4 4 3% ,蛋重分别提高 5 99% (P <0 0 5)和降低 2 89% ,受精率分别降低 2 0 4 %和提高3 85% ,破蛋率降低 ;当温度升至 31 5～ 33℃ ,持续 4d ,试验组Ⅰ和Ⅱ产蛋率、蛋重、受精率和破蛋率增加 ,但差异不显著。②处理第 1 1天 ,与对照组相比 ,试验组Ⅰ和Ⅱ的T3分别提高 2 5 6 %和 56 4 % ;处理第 1 5天 ,T3分别提高 75 8%和 6 3 6 %。③与对照组相比 ,处理第 1 1天 ,试验组Ⅰ和Ⅱ的T4 分别提高 32 2 %和降低 9 1 2 % ;处理第 1 5天 ,T4 分别降低 1 5 1 7%和提高 4 7 9% (P <0 0 5)。

Effect of daidzein on laying performance and serum thyroid hormone level in young laying hens under hot environmental condition

Ninety Lingnanhuang (Local breed) broiler breeders hens and nine roosters at 155 days of age were randomly assigned to three groups which were supplemented with daidzein at doses of 0,3 and 6 mg/kg diet (control, Exp Ⅰand Ⅱ).The animals were raised on ground under natural environmental condition at 22～33℃.The blood samples were collected on -1d(22℃),7d(23℃),11d(30 5℃),15 d(32 3℃).The results were shown as follows:(1)At 30 5℃, laying rate in the Exp Ⅰand Ⅱ increased by 30 0% and 44 3% compared with the control. Egg weight increased significantly in Exp Ⅰand decreased in Exp Ⅱ. Egg fertility rate decreased by 2 04% in Exp Ⅰ and increased by 3 85% in Exp Ⅱ. Cracked egg rate in Exp Ⅰand in ExpⅡ decreased slightly as compared with the control. When the temperature rose to 31 5～33℃,laying rate, fertility rate, egg weight and cracked egg rate in the groups supplemented with daidzein were higher than those of the control. (2)Compared to the control, serum T 3 level in Exp Ⅰand Ⅱincreased at 11 d and 15 d.(3)Serum T 4 level increased by 32 2% in Exp Ⅰ,while it decreased by 9 12% in Exp Ⅱat 11 d. At 15 d, serum T 4 level in ExpⅠ decreased by 15 17%, while it elevated by 47 9% (P <0 05)in Exp Ⅱ.