添加异丁酸、2-甲基丁酸和戊酸对牦牛瘤胃体外发酵参数和养分降解率的影响  

Effects of Supplementing Isobutyric Acid,2-Methylbutyric Acid and Valeric Acid on In Vitro Rumen Fermentation Parameters and Nutrient Degradation Rates of Yaks

作　　者：姜菲 赖琦 高彦华 彭忠利[1] 董利锋[2] 张佳雯 李潇 廖宇鹏 JIANG Fei;LAI Qi;GAO Yanhua;PENG Zhongli;DONG Lifeng;ZHANG Jiawen;LI Xiao;LIAO Yupeng(Key Laboratory of Animal Science of National Ethnic Affairs Commission,Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resources Reservation and Utilization,College of Animal and Veterinary Sciences,Southwest Minzu University,Chengdu 610041,China;Feed Research Institute,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Sichuan Action Biotech Co.,Ltd.,Guanghan 628300,China)

机构地区：[1]西南民族大学畜牧兽医学院,青藏高原动物遗传资源保护与利用教育部重点实验室,动物科学国家民委重点实验室,成都610041 [2]中国农业科学院饲料研究所,北京100081 [3]四川爱客信生物科技股份有限公司,广汉628300

出　　处：《动物营养学报》2022年第9期5915-5930,共16页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：西南民族大学中央高校基本科研业务费专项(2021PTJS20);四川省2021—2023年高等教育人才培养质量和教学改革项目(JG2021-414);国家现代农业技术体系四川肉牛创新团队建设项目(sccxtd-2020-13)。

摘　　要：本试验旨在研究添加异位酸(异丁酸、2-甲基丁酸和戊酸)对牦牛瘤胃体外发酵产气量、发酵参数和养分降解率的影响,以改善牦牛瘤胃发酵性能,提高对饲粮纤维的利用。首先利用康乃尔净碳水化合物-蛋白质体系(CNCPS)评价2种牧草(箭筈豌豆和燕麦)的营养价值;之后将箭筈豌豆和燕麦按5种不同比例(干物质基础)混合作为底物进行体外发酵,分别为组合1(100%箭筈豌豆)、组合2(75%箭筈豌豆+25%燕麦)、组合3(50%箭筈豌豆+50%燕麦)、组合4(25%箭筈豌豆+75%燕麦)和组合5(100%燕麦),筛选最佳组合作为发酵底物;最后分别添加0.3%、0.6%和0.9%(干物质基础)的异丁酸、2-甲基丁酸和戊酸,进行体外发酵试验,测定4、8、16、24、36、48、72 h产气量及72 h养分降解率和发酵参数。结果表明:1)CNCPS评价揭示箭筈豌豆的蛋白质品质优于燕麦,而碳水化合物品质低于燕麦。2)底物组合筛选试验表明50%箭筈豌豆+50%燕麦发酵效果最佳。3)添加异位酸的瘤胃体外发酵试验表明,各组的72 h累积产气量随时间延长显著增加(P<0.05)。与空白对照组相比,添加异丁酸、2-甲基丁酸和戊酸均显著降低了氨态氮含量(P<0.05);添加2-甲基丁酸显著增加了微生物蛋白(MCP)和总挥发性脂肪酸(TVFA)含量(P<0.05);添加戊酸显著增加了戊酸含量(P<0.05),但显著降低了乙酸、丙酸和TVFA含量(P<0.05)。异位酸添加水平对瘤胃体外发酵除乙酸和丁酸含量之外的VFA含量和乙酸/丙酸产生显著影响(P<0.05);随着异位酸添加水平的增加,丙酸、戊酸和TVFA含量先增加后降低,在0.6%添加水平最高,均显著高于0和0.9%添加水平(P<0.05);而异丁酸、异戊酸含量线性增加,在0.9%添加水平最高,显著高于0和0.3%添加水平(P<0.05)。综上所述,50%箭筈豌豆+50%燕麦为牦牛瘤胃体外发酵最佳底物组合,添加0.3%2-甲基丁酸或0.3%戊酸能够改善牦牛瘤胃体外发酵参数。This experiment was concocted to study the effects of supplementing isoacids(isobutyric acid,2-methylbutyric acid and valeric acid)on in vitro rumen gas production,fermentation parameters and nutrient degradation rates of yaks,in order to improve rumen fermentation performance and fiber utilization of yaks.Firstly,the Cornell net carbohydrate protein system(CNCPS)was utilized to evaluate the nutritional value of two forages(Vicia sativa and Avena sativa).Then,an in vitro fermentation was conducted using five different combinations of Vicia sativa and Avena sativa as fermentation substrates(dry matter basis),namely:combination 1(100%Vicia sativa),combination 2(75%Vicia sativa+25%Avena sativa),combination 3(50%Vicia sativa+50%Avena sativa),combination 4(25%Vicia sativa+75%Avena sativa)and combination 5(100%Avena sativa),to screen the optimal combination as fermentation substrate.Finally,0.3%,0.6%and 0.9%(dry matter basis)isobutyric acid,2-methylbutyric acid and valeric acid were supplemented individually in in vitro fermentation experiment,and the gas production at 4,8,16,24,36,48 and 72 h and nutrient degradation rates and fermentation parameters at 72 h were determined.The results showed as follows:1)the CNCPS valuation indicated the protein quality of Vicia sativa was better than that of Avena sativa,while carbohydrate quality was lower than that of Avena sativa.2)The substrate combination screening experiment showed that 50%Vicia sativa+50%Avena sativa had the best in vitro fermentation effect.3)The supplementing isoacids in vitro rumen fermentation experiment showed that the 72 h cumulative gas production was significantly increased with the prolongation of fermentation time(P<0.05).Compared with the blank control group,supplementing isobutyric acid,2-methylbutyric acid and valeric acid significantly decreased the ammonia nitrogen content(P<0.05);supplementing 2-methylbutyric acid significantly increased the microbial protein(MCP)and total volatile fatty acid(TVFA)contents(P<0.05);supplementing valeric acid si

关 键 词：异丁酸 2-甲基丁酸 戊酸 牦牛 体外产气法 燕麦 箭筈豌豆 

分 类 号：S816.7[农业科学—饲料科学] S823[农业科学—畜牧学]