Correlation of Rumen Gas Emissions with Microorganisms and Me-tabolites in Different Beef Cattle Breeds
To explore the correlation between gas emissions and rumen microbiota and metabolomics in different breeds of beef cattle.Three Chinese Steppe Red cattle,three Yanhuang cattle,and three Simmental hybrid cattle with an average weight of 403 kg and an age of 18 months were selected as the research objects.Under the same dietary conditions,a large animal respiratory calorimeter was used to monitor 24-hour gas emissions,and nontargeted metabolomics analysis was performed on the rumen microbiota and rumen fluid.The results showed that the methane emissions of Simmental hy-brid were significantly lower than those of Chinese Steppe Red cattle and Yanhuang cattle(P＜0.05);The molar ratio of propionic acid in Yanhuang cattle was significantly lower than that of Chinese Steppe Red cattle and Simmental hybrid;The molar ratio of isovaleric acid in Simmental hybrid was significantly lower than that in Chinese Steppe Red cattle and Yanhuang cattle(P＜0.05);The rumen ammonia nitrogen of Simmental hybrid was significantly lower than that of Chinese Steppe Red cattle and Yanhuang cattle(P＜0.05).The relative abundance of Vibrio Pseudobutyrivibrio in Yanhuang cattle was significantly higher than that in Chinese Steppe Red cattle and Simmental hybrid(P＜0.01),while the relative abundance of Mogibacterium and Selenomonas was significantly higher than that in Chinese Steppe Red cattle and Simmental hybrid(P＜0.05).The Prevotella,02d06,Pseudomo-nas,and Carnobacterium in Simmental hybrid were significantly higher than those in Chinese Steppe Red cattle and Yanhuang cattle(P＜0.05),while the Pseudobutyrivibrio were significantly higher than those in Chinese Steppe Red cattle and Yanhuang cattle(P＜0.01).The concentrations of secondary differential metabolites myristic acid and palmitic acid were significantly reduced in Yanhuang cattle and significantly increased in Simmental hybrid.At the same time,myristic acid and palmitic acid were enriched in the pathways of fatty acid biosynthesis,degradation,elongation,and biosynthesis of unsaturated fatty acids.After analyzing the association between metabolites and microorganisms,it was found that myristic acid and palmitic acid were significantly positively correlated with the genera Prevotella and Ruminococcus.The results indicate that the low methane emissions of Simmental hy-brid may be related to a decrease in the concentration of isovaleric acid and ammonia nitrogen;There is a negative correlation between the relative abundance of five rumen microorganisms(Prevotella,Carnobacterium,Butyrivibrio,Succiniclasticum and Ruminococcus);There is a positive correlation be-tween the concentration of metabolites palmitic acid and myristic acid.In summary,the relative abundance of Prevotella,Ruminococcus,and Succiniclasticum in Simmental hybrid is relatively high,leading to a significant increase in the concentration of metabolites such as myristic acid and pal-mitic acid,thereby reducing methane emissions in Simmental hybrid.Under identical dietary condi-tions,variations in the rumen microbiota and metabolites can contribute to the differences in meth-ane emissions among different beef cattle breeds.
万方数据
维普
