肉仔鸡体内锌和维生素A互作效应及其对锌表观存留率的影响

本研究采用二因素多水平有重复实验设计 ,研究了日粮中不同锌和维生素A水平对肉仔鸡体内维生素A代谢、锌在肝脏和胫骨中的沉积及锌表观存留率的影响。锌的添加水平为40、80、120、160、200、320mg/kg;维生素A的添加水平为2700和8800IU/kg。结果表明 ,在相同的维生素A水平下 ,血清维生素A浓度随日粮锌水平的提高而提高 ,肝脏的维生素A浓度则相应下降 ,说明锌对动员肝脏维生素A入血有重要作用。但当锌的添加量为320mg/kg 时 ,血清、肝脏和肾脏的维生素A浓度均较高 ,说明日粮较高的锌水平在动员肝脏维生素A入血的同时 ,可能也促进了肠道对维生素A的吸收。日粮较高水平的维生素A(8800IU/kg)有促进肝脏和胫骨锌沉积的趋势。日粮锌水平对锌的表观存留率有显著影响 ,表观存留率随锌水平的提高先提高 ,而后又下降

EFFECT OF VARIOUS LEVELS OF DIETARY ZINC AND VITAMIN A ON THE INTERACTION OF ZINC AND VITAMIN A AND ZINC APPARENT DEPOSITION IN BROILERS

Two factors'experiment with repeats was conducted on broilers to inverstigate the interaction between zinc and vitamin A,zinc concentration in liver and tibia,and zinc apparent deposition rate.The supplementary amount of zinc was 40,80,120,160,200 and 320mg/kg;of the vitamin A was 2700IU/kg and 8800IU/kg.Results showed that vitamin A concentration in serum increased with the increasing of zinc level in the diet,and that in livers decreased accordingly,which means that zinc can mobilize vitamin A of liver into serum.When dietary zinc level was 320mg/kg,vitamin A concentration in serum,liver and kidney increased at the same time,perhaps higher dietary zinc level promoted vitamin A absorption except for mobilizing it into serum.Higher dietary vitamin A level(8800IU/kg) increased zinc concentration in liver and tibia slightly.Zinc apparent deposition rate increased with the increasing of dietary zinc level within certain range and then decreased.