不同精粗比底物下添加亚硝酸钾对长期瘤胃体外发酵的影响  

Effects of nitrite supplementation with different concentrate to forage ratio on rumen long-term fermentation of sheep in vitro

作　　者：林淼[1] 张世杰 葛红帆 张蒙 巩帅 LIN Miao;ZHANG Shijie;GE Hongfan;ZHANG Meng;GONG Shuai(College of Animal Science and Technology,Yangzhou University,Yangzhou,Jiangsu Province 225009,China)

机构地区：[1]扬州大学动物科学与技术学院,江苏扬州225009

出　　处：《中国饲料》2020年第13期24-28,共5页China Feed

基　　金：国家自然科学基金项目(31301997);江苏省“青蓝工程”骨干教师;国家现代农业产业技术体系(CARS-36);江苏省高校优势学科建设工程资助项目。

摘　　要：本试验旨在研究在不同的玉米和苜蓿添加比例下添加亚硝酸钾对瘤胃体外发酵的影响。采用频繁传代模拟瘤胃发酵和2×2双因子试验设计,以不加亚硝酸钾为对照,首先以玉米:苜蓿=1:3培养30代,每隔24 h传代一次,再以玉米:苜蓿=3:1培养30代。每代测定24 h产气量,并采集样品,测定发酵液pH、亚硝酸盐(NO2-)和氨态氮(NH3-N)的浓度、挥发性脂肪酸(TVFA)及其组成比例。结果表明:(1)传代培养达30代,发酵液pH和产气量可达到稳定。(2)不同精粗比不影响NO2-的24 h剩余量和丁酸比例(P>0.05)。(3)添加亚硝酸钾显著提高了NH3-N浓度(P<0.01),但精粗比为3:1时,显著降低了NH3-N浓度(P<0.01)。(4)精粗比为1:3时添加亚硝酸钾降低了产气量、TVFA产量和乙酸比例,提高了pH和丙酸比例(P<0.01);相反,精粗比为3:1时添加亚硝酸钾不改变产气量、TVFA、乙酸和丙酸比例(P>0.05),降低了pH(P<0.01)。在本试验培养条件下,不同精粗比显著影响了瘤胃发酵参数,添加亚硝酸钾改变了瘤胃发酵类型。This study was designed to investigate the effects of nitrite addition in the substrate with different corn to alfalfa ratios on rumen fermentation in vitro.The frequent in vitro transferring method and 2×2 two factorial design were used.Cultured substrate with corn:alfalfa=1:3 for 30 generations followed by corn:alfalfa=3:1 for another 30 generations.Transferred the culture every 24 h.The gas production of 24 h was recorded for every generation,the samples were collected to determine pH,the concentration of nitrite(NO2-),ammonia nitrogen(NH3-N)and total volatile fatty acid(TVFA,including acetic acid,propionic acid and butyric acid).The results showed as follows:(1)The pH and gas production were stable when culture for 30 generations.(2)Different concentrate to forage didn't change the nitrite residue and butyrate percentage(P>0.05).(3)Nitrite supplementation significantly increased NH3-N concentration(P<0.01),however,ammonia concentration was transferred to decrease when concentrate to forage was 3:1.(4)Adding nitrite significantly decreased gas production,TVFA production and acetate proportion,increased pH and propionate proportion(P<0.01)when concentrate to forage was 1:3.By contrast,nitrite did not change gas production,TVFA production,acetate and propionate proportion(P>0.05),decreased pH(P<0.01)when concentrate to forage was 3:1.In this experimental culture system,different concentrate to forage affect rumen fermentation parameters,and nitrite supplementation changed rumen fermented type.

关 键 词：连续传代培养 亚硝酸盐 精粗比 瘤胃发酵 

分 类 号：S816.7[农业科学—饲料科学]