| The whole-plant corn belongs to Gramineae forage grass,which has high sugar content and biological yield,easy planting,strong stress resistance and easy silage.Soybean is a leguminous forage,which is difficult to make silage successfully due to its high protein content in nutrients,low soluble carbohydrate content and high buffer energy value when silage is not mixed with anything.Thus,the silage mixed with whole-plant corn and whole-plant soybean can make up for their respective shortcomings by using the high crude protein of soybean and the high carbohydrate of whole-plant corn to form silage when mixed in different proportions to explore the best ratio for mixed silage effect.In this experiment,whole-plant corn and whole-plant soybean were mixed for ensiling in order to improve the quality of mixed silage.By comparing the silage quality,microbial diversity and rumen degradation characteristics,the quality of silage mixed whole-plant corn and whole-plant soybean was analyzed,which provided scientific basis for the rational utilization of whole-plant soybean silage.The whole-plant corn and whole-plant soybean were mixed in ratios of 100%whole-plant corn silage alone(YM),80% whole-plant corn + 20% soybean(Q8D2),60% whole-plant corn + 40% whole-plant soybean(Q6D4)and 100% soybean silage alone(DD),and each layer was sprayed with Lactobacillus complex and placed in self-sealing bags for silage,and the samples were opened at 0 and 60 d for analysis of nutrient content,silage quality,aerobic stability and microbial the results of the analysis showed that.(1)Whole plant corn mixed with whole-plant soybeans after silage,with crude protein(CP)content increasing significantly(P< 0.05)with increasing proportion of soybeans and being highest in the DD group.Dry matter(DM)and soluble sugar(WSC)contents were significantly higher in the YM,Q8D2 and Q6D4 treatments compared to the DD group(P< 0.05).The ADF content of all mixed silage treatments was significantly lower than that of the whole-plant soybean treatment group(P<0.05),while the NDF content of the YM,Q8D2,Q6D4 and DD group treatments did not differ significantly.Among them,the nutritional quality was better with the mixed ratio of Q6D4 and the addition of the lactic acid bacteria complex additive.(2)Whole-plant corn and whole-plant soybean mixed silage,after silage,pH of whole corn and soybean mixed silage treatments were all below 4.3 within the normal range,lactic acid and acetic acid content were significantly higher than soybean single silage,no butyric acid was detected in all groups and fermentation quality was good.(3)The aerobic stability of the whole corn and whole-plant soybean silages increased as the proportion of whole maize decreased,with the Q6D4 group having the best aerobic stability;the number of lactic acid bacteria increased gradually with increasing aerobic exposure time,and the pH value also showed an increasing trend;at the same aerobic exposure time,the number of yeast increased significantly as the proportion of whole corn in the mixed silage decreased,and no moulds were found in any of the groups.No moulds were found in the groups.In conclusion,the addition of whole corn significantly improved the success rate of mixed silage,and the addition of a certain proportion of whole corn was beneficial for improving the aerobic stability of mixed silage and inhibiting the growth of moulds.(4)Differences in microflora species and numbers were observed among the groups by high-throughput sequencing.In the late stage of silage fermentation,the dominant phylum at the phylum level was Aspergillus;at the genus level,the dominant flora of whole corn mixed with whole-plant soybean in different proportions was Lactobacillus spp.with a proportion of 50.2%.At the species level,the relative abundance of Lactobacillus plantarum and Lactobacillus brevis was significantly higher in the Q6D4 group than in the other treatment groups(P< 0.05),with a combined abundance of 49.3%.(5)In vitro rumen digestion tests showed that all groups were within the suitable range for rumen microbial growth and all showed a decreasing trend in pH.As the proportion of whole corn added increased,fermentation gas production,dry matter digestibility were significantly increased(P < 0.05),while methane production was significantly lower(P < 0.05).In conclusion,the silage mixed with 60% whole plant corn and 40% whole soybean has the better nutritional value and silage quality. |
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