铁、铜对过量锌饲养小鸡生物效应的影响

本文对饲料中过量锌对小鸡铁,铜利用的影响以及补充适量铜或铁、铜的预防效果进行了研究。一日龄雄性小鸡喂基础饲料5天后按体重分成4组,用铁锌铜含量不同的实验饲料喂养28天,观察小鸡生长情况及血液生化指标。结果表明,高锌组小鸡生长不良,Hb下降13％,RBC,Hct,MCV均降低、FEP增加,呈现典型小细胞低色素贫血态,血液及肝肾中锌含量增加,铁和铜含量减少;红细胞超氧化物岐化酶和血浆铜兰蛋白活性下降。在含锌饲料中补充铜能改善小鸡的生长状况,体内铜水平及铜依赖酶活性,对改善贫血及体内铁水平的作用不明显。同时补铁则小鸡各项实验指标均得到明显改善。

INFLUENCE OF IRON AND COPPER ON BIOLOGICAL RESPONSE TO EXCESS DIETARY ZINC IN CHICK

A biological study was made to estimate the influence of excess dietary zinc, in vivo, on iron and copper status and their antagonism. Chicks were randomly divided into four groups (n= 22 each) according to body weight and were fed on experimental diet with different amounts of zinc, iron and copper for 28 days. The results were as follows; 1. Excess dietary zinc (400ppm) caused retardation of growth rate in experimental chicks, hypochromic anemia, elevation of blood and tissues (liver, kidney) zinc levels and lowering iron, copper and ceruloplasmin content,and eryth-rocyte Cu-Zn-superoxide dismutase activity; 2. Copper alone supplemented up to 40ppm to the excess zinc diet was able to improve the growth rate, body copper status and Cu-Za-superoxide dismutase activity, but no effect on anemia and body iron status; 3. Iron and copper were supplemented up to 400ppm and 40ppm respectively to excess zinc diet at same time, all the parameters were similar to the chicks fed basal diet. These data suggested that supplement of iron and copper at proper proportion to excess zinc diet can prevent the adverse effects of excess zinc on chicks.