慢性热应激期营养调控对放牧妊娠牛生殖激素含量、免疫功能及抗氧化能力的作用  

Effects of Nutritional Regulation on Reproductive Hormone Contents,Immune Function and Antioxidant Ability of Grazing Pregnant Cattle during Chronic Heat Stress Period

作　　者：武思同 敖日格乐[1] 王纯洁[2] 斯木吉德[1] 陈浩 张晨 曹家铭 徐萍 刘飞鸿 WU Sitong;Aorigrle;WANG Chunjie;Simujide;CHEN Hao;ZHANG Chen;CAO Jiaming;XU Ping;LIU Feihong(College of Animal Science,Inner Mongolia Agricultural University,Hohhot 010018,China;College of Veterinary Medicine,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学动物科学学院,呼和浩特010018 [2]内蒙古农业大学兽医学院,呼和浩特010018

出　　处：《动物营养学报》2021年第3期1545-1554,共10页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：国家重点研发计划项目(2018YFD0501703);国家自然科学基金项目(31772650,31660677);内蒙古自治区草原英才工程项目;农业部政府购买服务项目(16200157-8)。

摘　　要：本试验旨在研究营养调控对慢性热应激状态下的放牧妊娠牛生殖激素含量、免疫功能以及抗氧化能力的作用。试验选取夏季持续热应激期天然草场放牧的妊娠牛18头,随机分为试验组(营养调控)和对照组(仅放牧),每组9头。对照组妊娠牛每天自然放牧,试验组妊娠牛在此基础上归牧后进行补充饲喂精料2.5 kg/d。预试期10 d,试验期60 d。每天记录草场温湿指数,在试验期第1、30和60天早晨空腹进行颈静脉采集血液样本,测定其生殖相关激素含量、免疫功能及抗氧化能力相关指标,比较研究试验组和对照组间妊娠牛的各项血清指标的差异,及在试验组和对照组组内组间(不同时间点)的差异。结果表明:试验动物长期处于气温日较差较大的热应激环境,在试验第60天,试验组血清孕酮(PROG)、雌二醇(E2)含量显著高于对照组(P<0.05)。试验组组内组间血清催乳素(PRL)、三碘甲状腺原氨酸(T_(3))含量增加显著(P<0.05)。妊娠牛血清促卵泡素(FSH)含量在试验组组内组间均无显著差异(P>0.05)。在试验第60天,试验组血清白细胞介素-2(IL-2)和白细胞介素-4(IL-4)含量显著高于对照组(P<0.05),试验组组内组间血清免疫球蛋白A(IgA)、免疫球蛋白M(IgM)和免疫球蛋白G(IgG)含量均有显著提高(P<0.05),2组血清溶菌酶(LZ)含量均无显著差异(P>0.05)。试验组组内组间血清谷胱甘肽过氧化物酶(GSH-Px)活性和总抗氧化能力(T-AOC)显著增加(P<0.05),且试验组血清GSH-Px活性显著高于对照组(P<0.05)。2组血清超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量组内组间均无显著差异(P>0.05),但试验组血清SOD活性有高于对照组的趋势。综上所述,营养补饲有效地提高了放牧条件下妊娠牛的免疫功能和抗氧化能力,缓解了热应激对肉牛健康的危害,且显著提高了妊娠牛血清繁殖激素含量,对母牛繁殖性能的发挥具有积极作用。The purpose of this experiment was to explore the effects of nutritional regulation on the reproductive hormone contents,immune function and antioxidant capacity of grazing pregnant cattle under chronic heat stress.The experiment selected 18 pregnant cows grazing on natural grassland with continuous high temperature in summer,and randomly divided them into a test group(nutrition regulation)and a control group(only grazing),each with 9 pregnant cows.The control group grazed naturally every day.On this basis,after grazing,the test group was fed 2.5 kg of concentrate every day.The pre-trial period was 10 days and the trial period was 60 days.The daily temperature and humidity index of the grassland were recorded.On days 1,30 and 60 of the test period,blood was collected from the fasted jugular vein in the morning to determine the contents of reproductive hormones and related indicators of immunity and antioxidants,and to compare the difference in serum indexes between test group and control group and the difference between groups(different time points)within test group and control group.The results showed that the experimental animals were in a heat stress environment with a large daily temperature difference for a long time,and the serum progesterone(PROG)and estradiol(E2)contents in the test group were significantly higher than those in the control group on day 60 of test(P<0.05).Serum prolactin(PRL)and triiodothyronine(T_(3))contents in the test group were significantly increased(P<0.05).During the experiment period,there was no significant difference in serum follicle-stimulating hormone(FSH)content between groups within test group(P>0.05).On day 60 of test,serum interleukin-2(IL-2)and interleukin-4(IL-4)contents in the test group were significantly higher than those in the control group(P<0.05),and serum immunoglobulin A(IgA),immunoglobulin M(IgM)and immunoglobulin G(IgG)contents in the test group were increased significantly between groups within test group(P<0.05).There was no significant difference in serum

关 键 词：妊娠牛 热应激 生殖激素 免疫功能 抗氧化能力 营养调控 

分 类 号：S823[农业科学—畜牧学]