复合饲料添加剂对高温条件下肉牛生长性能、抗氧化指标及免疫相关基因表达的影响

Effect of compound feed additives on growth performance,antioxidant indexes and immune related gene expression of beef cattle under high temperature

试验旨在探究复合饲料添加剂对夏季高温条件下肉牛生长性能、抗氧化能力及免疫功能的影响。选用体重370 kg左右的西门塔尔牛32头,随机分为2组,每组16个重复,每个重复1头牛。对照组牛饲喂基础日粮,试验组牛饲喂在基础日粮中添加由荷叶粉、莲子钻芯粉、茶多酚和维生素C组成的复合饲料添加剂。试验期36 d。结果显示:整个试验期内温湿指数(THI)均大于72,试验牛处于持续热应激状态。与对照组相比,试验组牛平均日增重提高了6.25%,干物质采食量提高了1.84%(P>0.05)。与对照组相比,试验组牛血清中总超氧化物歧化酶(T-SOD)活性显著升高(P<0.05),总胆固醇(TC)和丙二醛(MDA)含量显著降低(P<0.05),且血液中IL-2和HSP70 mRNA的表达量显著降低(P<0.05)。研究表明,在夏季高温条件下,复合饲料添加剂具有提高肉牛日增重的趋势,可显著提高肉牛血清抗氧化能力,对热应激具有一定的缓解作用。

The experiment was to explore the effect of compound feed additives on growth performance, antioxidant capacity and immune function of beef cattle under high temperature conditions in summer. A total of 32 Simmental cattle weighing about 370 kg were selected and randomly divided into two groups, with 16 replicates in each group and one cattle in each replicate. The cattle in control group were fed with basal diet, and the cattle in test group were supplemented with compound feed additives consisting of lotus leaf powder, lotus seed core-penetrating powder, tea polyphenols and vitamin C in basal diet. The experimental period was 36 d. The results showed that THI was greater than 72 throughout test period, and the test cattle were in a state of continuous heat stress. Compared with control group, the average daily gain of cattle in test group increased by 6.25%, and the dry matter intake increased by 1.84%(P>0.05). Compared with control group, the activity of T-SOD in bovine serum of test group was significantly increased(P<0.05), the content of TC and MDA was significantly decreased(P<0.05), and the expressions of IL-2 and HSP70 mRNA in blood were significantly decreased(P<0.05). The study indicates that under high temperature conditions in summer, the addition of compound feed additives has a tendency to increase daily weight gain of beef cattle, which can significantly improve the antioxidant capacity of beef cattle serum, and has a certain alleviation effect on heat stress.