日粮中添加不同水平维生素A对肉牛机体抗氧化能力的影响

EFFECT OF DIFFERENT VITAMIN A LEVELS IN DIETS ON ANTIOXIDANT ABILITY OF BEEF CATTLE

本试验选用30头体重(350±10)kg西门塔尔×鲁西黄牛杂交肉牛,研究了不同水平维生素A(VA)对肉牛抗氧化能力的影响。将试牛随机分为对照组和试验组(日粮中分别添加维生素A1100、2200、3300、4400、5500IU/kg)。结果表明,日粮中添加3300～4400IU/kgVA可以明显提高肉牛机体的GSH-Px、CuZn-SOD两种抗氧化酶的活力和T-AOC(P<0.05),但不能提高T-SOD的活力(P>0.05);日粮中添加4400～5500IU/kgVA,可以明显降低肉牛血清中脂质过氧化反应产物MDA的含量(P<0.05);T-AOC、GHS-Px、CuZn-SOD抗氧化酶的活力和MDA的含量均可作为判断VA营养状况的指标,T-SOD不是检验VA的抗氧化作用的合适指标。肉牛VA的适宜添加水平在本试验条件下为3300IU/kg,添加4400IU/kg更有利于阻止机体脂质过氧化的程度,添加5500IU/kgVA不利于肉牛的抗氧化作用。

A trail was conducted to evaluate the effect of dietary vitamin A levels on antioxidant activity of beef cattle.Thirty crossbred beef-cattle （Simmental×Lu-xi） were randomly divided into control group and tested groups （adding 1100,2200,3300,4400,5500IU/kg VA to the basal diet respectively）.The results showed that the activities of GSH-Px and CuZn-SOD and T-AOC were increasing evidently （P 〈 0.05） as we added 3300-4400IU/kg VA into the diet.As adding 4400-5500IU/kg vitamin A to the diet, the content of MDA decreased remarkably.The T-AOC,the content of MDA and the activities of GSH-Px and CuZn-SOD,all are the proper index to estimated the nutritioal status of VA,but the T-SOD wasn＇t the proper index to test the antioxidant of VA.In the trial,the basal level of VA was 3300IU/kg and the adding 4400IU/kg of vitamin A could more effectively reduce the degree of lipid peroxidation,but all the items showed that the level of VA 5500IU/kg was against the antioxidation for the beef cattle.