利用血液维生素A的相对剂量反应评价肉仔鸡维生素A营养状况的研究

STUDY OF ASSESSMENT OF VITAMIN A STATUS IN BROILERS USING SERUM VITAMIN A RELATIVE DOSE RESPONSE TEST

试验1采用完全随机试验设计 ,将360只1日龄健康艾维茵肉仔鸡称重后随机分为12组 ,每组30只。其中 ,锌设0、5、40和80mg/kg4个添加水平 ;VA设0、3000和6000IU/kg3个添加水平 ,共构成12组。试验2也采用完全随机试验设计 ,将450只1日龄健康艾维茵肉仔鸡称重后随机分为15组 ,每组30只。其中 ,锌设25、65、145、305和625mg/kg5个添加水平 ,VA设3000、6000和12000IU/kg3个添加水平 ,共组成15组。通过研究日粮锌与VA水平对肉仔鸡生产性能、VA代谢和血清VA浓度的相对剂量反应(RDR)的影响 ,初探利用RDR评价肉仔鸡VA营养状况的可能性。结果表明 :在本试验条件下 ,应用血清VA的RDR值可监测肉仔鸡的VA营养状况 ,结合血清VA浓度可以判断引起血清VA浓度低下的原因 ,是由于日粮VA本身供给不足所致 ,还是由于其它原因引起的。但当日粮VA增加至一定水平时 。

Two experiments were conducted to explore the possibility of using serum vitamin A relative dose reaction (RDR) to evaluate vitamin A nutritional status in broilers. In experiment 1, the basic diet containing 4.67mg/kg of zinc was mainly made of corn starch and zinc-deficient soybean meal. Broilers were supplemented four levels of dietary zinc (0, 5.00, 40.00, 80.00mg/kg) and three levels of dietary vitamin A (0, 3000, 6000IU/kg) in a 2×4×3 factorial arrangement. In experiment 2, the basic diet containing 22.61mg/kg zinc was mainly made of corn and soybean meal. Broilers were supplemented five levels of dietary zinc(25,65,145,305,625mg/kg) and three levels of vitamin A (3000,6000,12000 IU/kg) in a 2×5×3 factorial arrangement.The results indicated that serum vitamin A relative dose response test could be a useful and reliable indicator of vitamin A status in broilers.Morever, RDR could be used to judge the decrease of serum vitamin A concentrations was caused by the deficiency of vitamin A in the diet or other factors. However, it was not sensitive for RDR to detect the nutritional status of vitamin A when vitamin A level of the diet was higher.