早期限饲对肉鸡体内脂质过氧化作用和抗氧化酶活性的影响

Effects of Early Feed Restriction on Lipid Peroxidation and Enzymatic Antioxidant Activity of Broiler

采用低温诱发肉鸡腹水综合征(AS),并观察早期限饲对常温和低温饲养时肉鸡AS的发病率、肉鸡体内脂质过氧化作用和抗氧化酶活性的影响.试验1,限饲处理组肉鸡分别于7～14日龄或7～21日龄每天给料8 h,对照组肉鸡全程自由采食.试验2,限饲组肉鸡分别于7～14日龄给予对照组肉鸡前一天饲料消耗量的60%或80%,对照组肉鸡自由采食.试验过程中连续测定肉鸡血浆超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)水平和腹水心脏指数(RV/TV值).结果显示低温显著升高了肉鸡血浆MDA浓度,降低了血浆SOD和GSH-Px的活性;低温饲养肉鸡5～6周龄时的RV/TV值显著升高,AS的发病率显著增加.限饲处理显著降低了肉鸡血浆MDA含量,并且限饲处理肉鸡生长后期血浆中SOD和GSH-Px活性显著高于自由采食组肉鸡.所有的限饲处理均能降低肉鸡AS的发病率,并且早期限饲处理肉鸡42日龄的RV/TV值显著低于非限饲肉鸡.这表明早期限饲能够减轻肉鸡体内脂质过氧化作用,提高机体抗氧化酶的活性,从而降低AS的发病率.

Experiments were conducted to investigate the effects of early feed restriction on the lipid peroxidation,enzymatic antioxidant activity and ascites incidence of broiler under normal or low ambient temperature. Broilers were exposed to low ambient temperature to induce ascites syndrome. In experiment 1, the restricted chicks were fed 8 hours per day either from day 7 to day 14 or from day 7 to day 21, while the controlled chicks were fed ad libitum. In experiment 2, the restricted chicks were fed 80% or 60% of previous 24 hour feed consumption of full-fed controls for 7 days from day 7 to day 14, while the full-fed controls were fed ad libitum all through the experiment. Plasma malonilaldehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) concentration and ascites heart index (RV/TV ratio) were continuously surveyed. The results showed that low temperature significantly increased the plasma MDA concentration and decreased the plasma SOD and GSH-Px activity. The RV/TV ratio at week 5~6 and the ascites morbidity were significantly increased in low temperature treated broiler. Early feed restriction markedly decreased the plasma MDA concentration. The plasma SOD and GSH-Px activity of feed restricted broiler was markedly higher than that of the fed ad libitum broiler during late experimental period. All early feed restriction treating reduced ascites morbidity. The RV/TV ratio of feed restricted chicks was lower than that of the uncontrolled chicks on day 42. The results indicated that early feed restriction alleviated the lipid peroxidation, enhanced the enzymatic antioxidant activity and finally reduced the ascites morbidity of broiler.