本试验旨在研究在夏季高温条件下添加金银花提取物对热应激肉牛血清激素及抗氧化指标的影响。选择体重(360±20) kg的健康锦江黄牛20头分为4组,分别在精料中添加0(对照)、0.2%、0.4%和0.6%金银花提取物,每组5个重复,每个重复1头。预试期10 d,正试期60 d。结果显示:与对照组比较,1)在40 d,0.2%和0.6%组试验牛的体温显著低于对照组(P<0.05);金银花提取物对肉牛日增重无显著影响(P>0.05)。2)试验组肉牛的血清三碘甲状腺原氨酸(T₃)、甲状腺素(T₄)含量升高,皮质醇(COR)含量下降。3)试验组肉牛血清总抗氧化能力(T-AOC)、谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)活性均提高,丙二醛(MDA)含量降低。结果提示,金银花提取物可改善肉牛抗氧化性能,缓解肉牛热应激反应,但对增重没有显著影响;综合各项指标认为精料中添加0.2%较为适宜。

This study was conducted to investigate the effects of Honeysuckle extracts on serum hormones and antioxidant indexes of beef cattle under heat stress of high temperature environment in summer. Twenty healthy Jinjiang yellow cattle with body weight of (360±20) kg were divided into four groups with five in each group and one cattle per replicate. Honeysuckle extracts at 0(control), 0.2%, 0.4% and 0.6% were added in concentrates. The pretest lasted for 10 days, and the test lasted for 60 days. The results showed as follows: compared with control group, 1) body temperature in 0.2% and 0.6% groups were significantly declined on days 40 (P<0.05); there was no significant effects on daily gain (P>0.05). 2) Serum contents of triiodothyronine and thyroxine in experimental groups were increased, but serum cortisol content was declined. 3) Serum activities of superoxide dismutase, glutathione peroxidase and total antioxidant capacity in experimental groups were enhanced, but serum content of malondialdehyde was decreased. These results indicate that dietary supplementation of Honeysuckle extracts improve antioxidant capability, and relieve stress reaction of beef cattle, but had no significant effects on weight gain; the optimal level is 0.2% supplemented in concentrate considered all the indexes.