单宁酸对湖羊瘤胃动态发酵和血清抗氧化能力的影响

Effects of Dietary Tannic Acid on Rumen Dynamic Fermentation and Serum Antioxidant Capacity of Hu Sheep

试验主要研究饲粮中添加单宁酸对湖羊瘤胃动态发酵和血清抗氧化能力的影响。采用交叉试验设计,选择6只体重和年龄相似、体况良好,安装了永久瘤胃瘘管的湖羊,随机分为2组,分别为对照组(基础饲粮)和单宁酸组(基础饲粮+2%单宁酸),每组3只。试验分2期进行,每期15 d,其中预试期10 d,正试期5 d。在正试期的前2 d采用动态pH监测系统对湖羊瘤胃pH进行24 h动态监测。在正试期的后2 d采集食后0、1、3、5 h和7 h的瘤胃液和血清,用于瘤胃挥发性脂肪酸(volatile fatty acid,VFA)、氨氮浓度及血清抗氧化指标的测定。结果表明:饲粮中添加单宁酸显著提高湖羊瘤胃丁酸摩尔比和异戊酸摩尔比(P<0.05),而显著降低瘤胃氨氮浓度和总挥发性脂肪酸(total volatile fatty acid,TVFA)含量(P<0.05)。饲粮中添加单宁酸显著降低湖羊血清总超氧化物歧化酶(total su⁃peroxide dismutase,T-SOD)活性(P<0.05),显著提高谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性和丙二醛(malondialdehyde,MDA)含量(P<0.05)。综上所述,饲粮中添加单宁酸具有保持瘤胃内环境稳态和提高血清抗氧化能力的作用。

This study aimed to investigate the ef⁃fects of dietary tannic acid on rumen dynamic fer⁃mentation and serum antioxidant capacity of Hu sheep.Six sheep with similar body weight and age,in good body condition and fitted with perma⁃nent rumen fistulae were selected and divided in⁃to two groups that received basal diet(control group)and basal diet supplemented with 2%tannic acid(tannic acid group)respectively,with three sheep in each group.The 15 days experiment included two phases,acclimation period for 10 days and sampling period for 5 days.During the first 2 days of the sampling period,rumen pH was dynamically monitored for 24 hours by a dynamic pH monitoring system.Rumen fluid and serum samples were col⁃lected at the 0,1st,3rd,5th hour and 7th hour after feeding in the last 2 days of the sampling period,to determine the concentration of volatile fatty acids(VFA)and ammonia nitrogen and the serum antioxi⁃dant indexes.The results showed that dietary tannic acid significantly increased the rumen molar ratio of butyric acid and isovalerate(P<0.05),but significantly decreased the rumen ammonia nitrogen and total volatile fatty acid(TVFA)concentrations(P<0.05).Additionally,tannic acid significantly decreased the activity of total superoxide dismutase(T-SOD)(P<0.05),and significantly increased the activity of gluta⁃thione peroxidase(GSH-Px)in serum(P<0.05)and the concentration of malondialdehyde(MDA)in se⁃rum as well(P<0.05).In conclusion,dietary tannic acid could maintain rumen homeostasis and improve serum antioxidant capacity.