日粮添加V_E和V_C对肺动脉高压综合征患鸡自由基代谢的影响

Effect of Dietary Vitamin C and E on Metabolism of Free Radicals in Broilers with Pulmonary Hypertension Syndrome

将 38 0只 AA商品肉鸡随机分为 A组 10 0只 ,B、C、D和 E组各 70只 ,14日龄前常规饲养。14日龄后 ,B、C、D和E组舍温按每日 1～ 2℃由 2 5℃逐步降至 12℃ ,同时日粮中按 1.5 mg/ kg的剂量添加 T3以诱发肺动脉高压综合征(PHS) ;C、D组在日粮中分别按 5 0 0、10 0 mg/ kg的剂量添加维生素 C和 E;而 E组同时添加维生素 C和 E,A组仍常规饲养 ,至试验结束。记录每周各组鸡群的 PHS发病数、平均体质量和采食量 ,并每周每组取 10只鸡采血和扑杀 ,测定其红细胞压积 (PCV)、血浆、肺和肝组织的超氧化物歧化酶 (SOD)及脂质过氧化物的降解产物丙二醛 (MDA )浓度 ;取心脏测定其右心室和全心室质量比 (RV/ TV)。结果显示 ,环境低温和日粮添加 T3极显著增加了肉鸡 PHS的发病率 (P<0 .0 1)。 C、E组的肉鸡 PHS发病率以及血浆、肺和肝组织的 MDA值均极显著降低 (P<0 .0 1) ,血浆、肺和肝组织的 SOD值均极显著增加 (P<0 .0 1) ,但增重、饲料转换率、血液 PCV值和心脏指数 RV/ TV值未发生改变 ;D组 5周龄后的血浆 MDA值则极显著降低 (P<0 .0 1)以及血浆、肺和肝组的 SOD值极显著增加 (P<0 .0 1) ,而肺和肝组织的 MDA值和肉鸡 PHS发病率未发生改变。由此表明 ,日粮添加维生素 C明显阻断了低温和 T3条件下肉鸡体内脂质过氧?

Three hundred and eighty 1-day-old Arbor Acres commercial broilers were divided randomly into control(A) and experimental(B,C,D and E) groups.All broilers were fed with a normal diet before 14 days of age.In experimental groups B,C,D and E,broilers were subjected to a change of temperature by lowering 1-2℃ per day from 25℃(day 14) down to 12℃,and then maintained at this ambient temperature until 7 weeks of age.At the same time,dietary 3,3,5-triiodothyronine(T_3) at 1.5 mg/kg was added into groups B,C,D and E in order to induce pulmonary hypertension syndrome(PHS).Dietary vitamin C at 500 mg/kg and vitamin E at 100 mg/kg were respectively added in groups C and D.Dietary vitamin C at 500 mg/kg together with vitamin E at 100 mg/kg were added into groups E.Moreover,body weight gain,feed conversion rate and PHS incidence were measured weekly.Blood samples were taken from 10 killed birds per group weekly from day 14 on,for determination of the packed cell volume(PCV),the concentrations of superoxide dismutase(SOD) and MDA in plasma,lung and liver.The right ventricle(RV) and the total ventricle(TV) were weighed,and the RV/TV ratio was calculated.The results indicated that the lower ambient temperature and dietary T_3 significantly increased PHS incidence (P<0.01).In the groups C and E,the PHS incidence and MDA in plasma,lung and liver significantly reduced(P<0.01),and SOD in plasma,lung and liver significantly increased(P<0.01),but did not change the body weight gain,feed conversion rate,PCV and RV/TV;and that in the group D,significantly decreased MDA in plasma after 5 weeks of age(P<0.01) and significantly increased SOD in plasma,lung and liver(P<0.01),but did not change MDA in lung and liver and the incidence of PHS,reflecting that the dietary vitamin C may stop the lipid peroxidation,eliminate the free radicals,increase the antioxidative capacity and reduce the incidence of PHS in broilers in the cold ambient and dietary T_3;and that the vitamin C and E may increase the antioxidative capacity in broilers in the cold ambient and dietary T_3;but does not change the growth performance in broilers;and that although the dietary vitamin E may increase partly the antioxidation,but does not prevent the incidence of PHS in broilers.