摘要
试验旨在研究不同中性洗涤纤维(NDF)与非纤维性碳水化合物(NFC)比例的玉米秸秆饲粮对肉羊不同时间点瘤胃发酵及甲烷排放动态变化的影响。采用4×4拉丁方设计,将12只安装永久性瘤胃瘘管的杜泊×小尾寒羊杂交羯羊随机分成4组,每组3只,按维持水平分别饲喂NDF/NFC比为饲粮1(3.60)、饲粮2(2.70)、饲粮3(1.75)和饲粮4(1.05)的全混合饲粮。试验共进行4期,每期23d,在正式期内利用Sable系统呼吸测定箱测定不同时间点甲烷排放量和瘤胃液pH、氨态氮(NH3-N)及挥发性脂肪酸(VFA)。结果表明:采食0h、6h、8h饲粮4瘤胃pH显著低于饲粮1(P<0.05)。同一时间点,各组之间的氨态氮差异显著(P<0.05);采食量4h时,饲粮1的乙酸占总挥发酸的比例显著高于其他三种饲粮(P<0.05),采食后0h、2h后,饲粮4丁酸占总挥发酸的比例显著高于其他三种饲粮(P<0.05)。采食后4h,饲粮4乙酸/丙酸显著低于其他三种饲粮。而在采食后的0~2h、2~4h、6~8h,饲粮4甲烷排放量显著低于其他三种饲粮(P<0.05)。试验结果表明,在维持饲喂水平下,随着饲粮NDF/NFC降低,NDF/NFC为1.05的饲粮瘤胃液pH、乙酸占TVFA的比例较低,甲烷排放量也较少。同时,甲烷排放量随着瘤胃发酵的动态变化而变化,在饲喂0~2h内,肉羊甲烷排放量最高。
This study investigated the effects of corn-stalk-based diets with different ratios of neutral detergent fiber(NDF)to non-fiber carbohydrates(NFC)on the rumen fermentation and methane emission of mutton sheep.The trial was conducted by a 4×4 Latin square design:12 Dorper × thin tailed Han crossbred wethers with permanent rumen fistulas were randomly divided into 4 groups with 3 sheep each,and each group was randomly fed one of four total mixed rations with a ratio of NDF/NFC as 3.60,2.70,1.75 or 1.05(Diet 1,2,3,and 4,respectively).All animals were fed at maintenance level.The trial included 4 periods,and each period lasted for 23 dwith a 10-d adaptation period.The methane emission was measured by respiration chambers with Sable system,rumen fluid pH,ammonia nitrogen(NH3-N)and volatile fatty acid(VFA)were measured at different time points.The results showed that 0,6,and 8 h after feeding the rumen pH value of Diet 4 was lower than that of Diet 1(P<0.05).Ruminal NH3-N was different between groups(P<0.05);4 hafter feeding,the proportion of ruminal acetic acid in the total volatile fatty acid(TVFA)for Diet 1 was higher than that of the other three diets(P<0.05);0 and 2 h after feeding,accounted for the proportion of butyric acid in the total volatile acid for Diet 4 was higher than that of the other three diets(P<0.05).Four hours after feeding,the ratio of acetate to propionic acid for Diet 4 was lower than that of the other three diets(P<0.05).During the periods of 0~2,2~4 h,and 6~8 hafter feeding,methane emissions from the animals on Diet 4 were lower than those on the other diets(P<0.05).Therefore,it is concluded that by maintaining the feeding level,the animals fed the diet with a NDF/NFC ratio of 1.05 had a low ruminal pH and low proportion of acetate in TVFA,and less methane emissions.Methane emissions also changed dynamically with the changes of rumen fermentation,with methane emissions reaching the peak during the period of 0 to 2 hafter feeding in mutton sheep.
出处
《家畜生态学报》
北大核心
2018年第1期31-36,共6页
Journal of Domestic Animal Ecology
基金
国家自然科学基金(41475126)
中国农业科学院科技创新工程(1610382017002)
国家肉羊产业技术体系(CARS-39)
关键词
NDF/NFC
瘤胃发酵
甲烷
肉羊
neutral detergent fiber/non-fiber carbohydrates
rumen fermentation
methane emission
mutton sheep
