Effects of Temperature on Ensiling Fermentation Quality of Cabbage Wastes and Microbial Community Analysis

In order to explore the ensiling feasibility of discarded Chinese cabbage at different temperatures,the ensilage quality of cabbage wastes at different temperatures were discussed according to the climatic conditions in Lanzhou. The microbial communities during ensiling were analyzed by high-throughput sequencing. Three temperature treatments,such as OA(low),RA(medium)and HA(high),were set up. After 30 days of ensiling fermentation,qualities were comprehensively analyzed in terms of sensory,the content of dry matter and organic component content,fermentation characteris. The influence of temperature on microbial communities were analyzed by Illumina MiSeq platform. The results showed that there was no mildew or spoilage and deterioration in three treatments at 30 days of silage,and the sensory quality was good or superior. Ensiling fermentation at medium-temperature can produce abundant organic acids such as lactic acid and acetic acid,which reduced the pH to 3.95,the ammonia nitrogen content was only 3.45 g/100 g(total nitrogen),the content of neutral detergent fiber and acid detergent fiber were reduced to 21.51 g/100 g DM and 18.36 g/100 g DM,respectively,the content of crude protein achieved 18.04 g/100 g DM.Microbial diversity analysis showed that the maximum number of OTUs in medium-temperature silages was 87,and the microbial richness and diversity were better than that of others. Firmicutes(relative abundance 87.27%)and Lactobacillus(relative abundance 80.07%)were the dominant bacteria at the phylum and genus level,respectively. The total relative abundance of lactic acid bacteria was over 87% at medium temperature,which maintained good lactic acid fermentation intensity. In conclusion,it is recommended that cabbage wastes can obtain good ensiling quality when ensilaged at medium temperature(18±1)℃,and the changes of organic composition is conducive to the improvement of forage value.