本试验旨在研究黄芪多糖(APS)对氢化可的松诱导的肉仔鸡氧化应激模型生长性能、脏器指数和抗氧化能力的影响。选用1日龄的爱拔益加(AA)肉仔鸡256只,按试验要求随机分为4组,每组8个重复,每个重复8只鸡。对照组(A组)和模型组(B组)饲喂不添加APS的基础饲粮,试验1组(C组)和试验2组(D组)饲喂在基础饲粮中分别添加0.4%和0.8% APS的试验饲粮。试验预试期7d,从第8天开始除A组(饮用蒸馏水)外,其余各组均在饮水中添加20mg/L氢化可的松造模,连续5 d;同时C组和D组饲喂添加APS的试验饲粮至第21天。结果表明:通过在饲粮中添加APS,可改善肉仔鸡的氧化应激状态,促进动物生长,C、D组14日龄的体重和1~14日龄的平均日增重均极显著高于A、B组(P<0.01),D组21日龄的体重和1~21日龄的平均日增重均显著高于B组(P<0.05);与B组相比,APS显著提高了14日龄氧化应激状态下肉仔鸡C组的脾脏指数、C组和D组的胸腺指数(P<0.05),但对21日龄脏器指数(D组肝脏指数、C组和D组脾脏指数除外)的影响均不显著(P>0.05);与B组相比,APS还可极显著降低D组14日龄肝脏和21日龄血清中丙二醛的含量(P<0.01),并能显著提高C组21日龄肝脏中总超氧化物歧化酶的活性(P<0.05)。结果提示,APS具有缓解氢化可的松产生的氧化应激,促进动物生长、脏器指数和抗氧化能力的作用。

This experiment was conducted to study the effects of Astragalus polysaccharide (APS) on growth performance, viscera indexes and antioxidant capacity in broilers under oxidative stress by hydrocortisone induction. Two hundred fifty-six healthy 1-day-old Arbor Acres broilers were randomly assigned to four groups with eight replicates per group and eight broilers per replicate. Control group (group A) and model group (group B) received a basal diet without APS, and experimental groups (groups C and D) received the basal diet supplemented with 0.4% and 0.8% APS, respectively. After a seven-day preliminary trial period, on day 8, 20 mg/L hydrocortisone was added into the drinking water of groups except group A (drank distilled water) for 5 days; at the same time, groups C and D received the basal diet supplemented with 0.4% and 0.8% APS for 21 days, respectively. The results showed as follows:1) adding APS in the diets improved the conditions of broiler oxidative stress, and promoted growth. The body weight at 14 days of age and average daily gain (ADG) at 1 to 14 days of age in groups C and D were significantly higher than those in groups A and B (P<0.01), and the body weight at 21 days of age and ADG at 1 to 21 days of age in group D were significantly higher than those in group B (P<0.05). 2) Compared with group B, adding APS in the diets significantly improved the viscera indexes (spleen index in group C, thymus index in groups C and D) of the 14-day-old broilers under oxidative stress status (P<0.05), but there were no effects on viscera indexes (except hepatic index in group D and spleen index in groups C and D) of the 21-day-old broilers (P>0.05). 3) Compared with group B, adding APS in the diets also significantly decreased hepatic malondialdehyde (MDA) content at 14 days of age and serum MDA content at 21 days of age in group D (P<0.01), and promoted hepatic total superoxide dismutase (T-SOD) activity at 21 days of age in group C (P<0.05). These results indicate that APS can relieve oxidative stress damage, and improve the animal growth, viscera indexes and antioxidant capacity.