日粮高铜对雏鸡法氏囊影响的研究

Effect of Dietary High Copper on the Bursa of Fabricius in the Chicken

本试验旨在研究高铜对雏鸡法氏囊的影响。选用1日龄艾维茵肉鸡健雏420只,随机分为7组,分别喂以对照日粮(Cu 11 mg/kg)和高铜日粮(Cu 100 mg/kg,高铜Ⅰ组;Cu 200 mg/kg,高铜Ⅱ组;Cu 300 mg/kg,高铜Ⅲ组;Cu 400 mg/kg,高铜Ⅳ组;Cu 500 mg/kg,高铜Ⅴ组;Cu 600 mg/kg,高铜Ⅵ组)6周。结果表明:(1)高铜Ⅰ、Ⅱ组雏鸡法氏囊组织学变化与对照组比较不明显,高铜Ⅲ、Ⅳ、Ⅴ、Ⅵ组雏鸡法氏囊组织结构呈不同程度的病变;(2)高铜Ⅰ、Ⅱ组雏鸡法氏囊质量、生长指数与对照组比较均增高(P>0.05),高铜Ⅲ、Ⅳ、Ⅴ、Ⅵ组雏鸡法氏囊质量、生长指数均不同程度地降低;(3)高铜Ⅰ、Ⅱ组雏鸡法氏囊细胞周期中增殖指数(PI)在试验期间均高于对照组(P>0.05),高铜Ⅲ、Ⅳ、Ⅴ、Ⅵ组雏鸡法氏囊细胞周期中增殖指数(PI)不同程度地降低;(4)各高铜组雏鸡法氏囊细胞凋亡率在试验期间与对照组比较均增高,与日粮含铜量呈正相关,其中高铜Ⅰ、Ⅱ组与对照组比较差异均不显著(P>0.05)。由本试验可见,日粮铜含量在11~200 mg/kg能够促进雏鸡法氏囊的发育,而高于300 mg/kg时不同程度地抑制了雏鸡法氏囊的发育,导致雏鸡体液免疫功能受损。

The experiment was conducted with the objective of examining the effects of high copper on the bursa of Fabricius in the chicken by the methods of experimental pathology and flow cytometry （FCM）. 420 one-day-old Avian chickens were randomly divided into seven groups, and fed on control diet （Cu 11 mg/kg） and high copper diets （Cu 100 mg/kg,high copper group Ⅰ ; Cu 200 mg/kg,high copper group Ⅱ ;Cu 300 mg/kg, high copper group Ⅲ ;Cu 400 mg/kg, high copper group Ⅳ ;Cu 500 mg/kg, high copper group Ⅴ ;Cu 600 mg/kg, high copper group Ⅵ）for six weeks,respectively. The results showed that histological changes were observed in high copper groups Ⅲ, Ⅳ, Ⅴ and Ⅵ in comparison with those of control group. The weight and the growth index of the bursa of Fabricius were higher in high copper groups Ⅰ and Ⅱ （P〉0.05） ,and lower in high copper groups Ⅲ , Ⅳ, Ⅴ and Ⅵ than that in control group（P^0.05 or P〈0.01）. The proliferation index（PI） of the bursa of Fabricius was increased in high copper groups Ⅰ and Ⅱ （P〉0. 05）,and decreased in high copper groups Ⅲ, Ⅳ, Ⅴ and Ⅵ （P〈0. 05 or P〈0. 01）compared with that of control group. Percentage of apoptotic lymphocytes in the bursa of Fabricius was higher in high copper groups Ⅲ, Ⅳ, Ⅴ and Ⅵ than that in control group（P〈0.05 or P〈 0.01）. It is concluded that dietary copper in excess of 300 mg/kg inhibited the development of bursa of Fabricius, caused pathological changes in the bursa of Fabricius and impaired humoral immune function,and that 11-200 mg/kg of copper in diet was helpful for the development of the bursa of Fabricius.