摘要
Methane emissions from ruminants enhance global warming and lead to a loss of feed energy. The emissions are low when fed brassica crops, but the factors contributing to low emissions are unknown. A meta‐analysis was conducted with individual animal data collected from seven experiments. In these experiments, methane emissions were measured using respiration chambers. Animal characteristics, feed chemical composition and rumen fermentation parameters were included for the analysis using multiple regression models. Feed intake level, animal live weight and age were animal factors that were weakly and negatively related to methane yield (g/dry matter intake). The duration in which sheep were fed brassica crops was a significant contributor in the model, suggesting that the effect on emissions diminishes with time. Among a range of feed chemical composition characters, acid detergent fibre and hot‐water‐soluble carbohydrate contributed significantly to the model, suggesting that both structural and soluble carbohydrates affect methane formation in the rumen. There was no significant correlation between the concentration of sulphate in brassicas and emissions, but nitrate was moderately and negatively correlated with methane yield (r = −.53). Short‐chain fatty acid profiles in the rumen of animals fed brassicas were different from those fed pasture, but these parameters only moderately correlated to methane emissions (r = .42). Feeding forage rape resulted in low rumen pH. The pH before morning feeding was strongly correlated to methane yield (r = .90). Rumen pH, together with microbial communities mediated by pH, might lead to low emissions. Bacteria known to produce hydrogen were relatively less abundant in the rumen contents of brassica‐fed animals than pasture‐fed animals. In conclusion, animal and feed factors, rumen fermentation and microbial communities all affect methane emissions to some extent. The interactions of these factors with each other thus contribute to methane emissions from brassica‐fed sheep.
摘要译文
反刍动物的甲烷排放增强了全球变暖，导致饲料能量丧失。当美联储芸苔作物时，排放量很低，但为低排放的因素是未知的。通过从七个实验中收集的个体动物数据进行了META分析。在这些实验中，使用呼吸室测量甲烷排放。使用多元回归模型将动物特性，饲料化学成分和瘤胃发酵参数包括分析。进料进气水平，动物活体重和年龄是与甲烷产量（G /干物质摄入量）无弱和呈负相关的动物因素。绵羊喂养芸薹属作物的持续时间是该模型中的重要贡献者，表明对排放的影响随时间减少。在一系列饲料化学成分特征中，酸性洗涤剂纤维和热水 - 可溶性碳水化合物对该模型产生了显着贡献，表明结构和可溶性碳水化合物均为瘤胃中的甲烷形成。硫乳酸盐和排放中硫酸盐浓度之间没有显着的相关性，但硝酸盐与甲烷产率（R = -.53）相当且呈负相关。喂养的动物瘤胃中的短链脂肪酸谱不同于那些喂养的牧场不同，但这些参数仅与甲烷排放（R = .42）中度相连。饲料饲料强奸导致瘤胃低温。早晨之前的pH值与甲烷产率强烈相关（R = .90）。瘤胃pH与pH值介导的微生物群落一起可能导致低排放量。在野生饲料的动物的尿布动物的瘤胃内含量中，已知产生氢的细菌比牧草动物的瘤胃含量相对较少。总之，动物和饲料因素，瘤胃发酵和微生物群落都会在一定程度上影响甲烷排放。这些因素彼此的相互作用因此有助于甘草喂养绵羊的甲烷排放。
Yuhua He[1];Xuezhao Sun[1];Peihua You[2]. Animal, feed and rumen fermentation attributes associated with methane emissions from sheep fed brassica crops[J]. Journal of Animal Physiology and Animal Nutrition, 2021,105(2): 210-218