Study On Methanogenesis And Energy Metabolism Of Mutton Sheep With Different Protein Materials

The purpose of this experiment was to study the effects of different protein materials on methane emission of mutton sheep,in order to provide theoretical basis and data support for carbon and nitrogen emission reduction of meat sheep breeding industry.Five protein raw materials,cottonseed meal,rapeseed meal DDGS,soybean meal and fermented soybean meal,were selected in this experiment.The effects of different protein materials on CH4 yield,rumen fermentation characteristics,micro flora,nutrient apparent digest ibility and energy metabolism of meat sheep were studied by experiments in vivo.1.Effects of different protein materials on rumen fermentation and methane production in vivo:36 meat sheep were randomly divided into 6 groups with 6 replicates in each group and 1 sheep in each replicate The control group was fed a basal diet,and the experimental groups were fed the same amount of five protein materials to replace the basal diet with 15%proportion,respectively.The results showed that compared with the control group,the CH4 yield was increased in the five protein materials groups,and the effects of rape seed meal,DDGS,soybean meal and fermented soybean meal groups were significant(P<0.05).Rumen fluid pH of rapeseed meal and soybean meal groups was significantly increased(P<0.05);The concentration of ammonia nitrogen in cottonseed meal and fermented soybean meal groups was significantly increased(P<0.05).All the five protein materials groups decreased the ratio of ethylene to propylene,and the rumen fermentation pattern tended to be propionic acid fermentation pattern.The results showed that cottonseed meal was the best protein in terms of methane emission,followed by DDGS,fermented soybean meal,soybean meal and rapeseed meal.2.Effects of different protein materials on microflora:The results showed that the dominant bacteria phyla and genera of methanogens were not changed in the five experimental groups:which were Euryarchaea and Merhauobrebacrer,respectively.The relative abundance of methanobrebacter in the four groups was significantly increased except the cottonseed meal group(P<0.05).The dominant bacteria in cottonseed meal group were Firumicures,and the abundance of significantly decreased while the abundance of Firuicures was signifi cantly increased(P<0.05).The dominant bacteria in the four groups except cottonseed meal group were Bacteroides Prevorella was dominant in each group.3.Effects of different protein materials on apparent digestibility of nutrient and energy metabolism:The results showed that the digestibility of DM in the five protein materials groups was increased(P>0.05),and the OM digestibility in the four groups except cottonseed meal group was also increased(P>0.05).The digestibility of CP in five protein materials groups was significantly increased(P<0.05).DE and ME were increased in five protein materials groups(P>0.05).The results showed that soybean meal had the best apparent digestibility,followed by rapeseed meal,DDGS,fermented soybean meal and cottonseed meal.In terms of effective energy value,DDGS had the best quality,followed by soybean meal,rapeseed meal,fermented soybean meal and cottonseed meal.