| In recent years,with the rapid development of dairy industry,the population of dairy cow and the total milk production have dramatically increased in China.However,the amount of milk produced per cow is lower,which is limited by the shortage of high-quality feed.Corn silage is one of the important roughages for dairy cows.Although the production of corn silage has been vigorously promoted with the support of national policies,the production level of corn silage in China is low such as the absence of silage-special corn varieties,which is one of the main limiting factors for the production of quality corn silage.The present study aimed to compare the production performance,fermentation quality,microbial community,and aerobic stability among different varieties of corn silage.Ten corn varieties(five silage-special corn varieties and five dual-purpose corn silage varieties),widely cultivated in temperate monsoon climate regions of China,were ensiled for 90 days with or without lactic acid bacterial inoculants.The results of the study can provide theoretical basis for selecting corn varieties and inoculants for the forage production.1 Production performance of different varieties of corn silageThe objective of this experiment was to assess the production performance of different varieties of silage-special corn(Zheng 1,Jingjiu 16,Beinong 356,Yu 23,and Beinong 208)and dual-purpose corn silage(Jingjiu 166,Dajingjiu 06,Dajingjiu 3912,Dajingjiu 4059,and Dajingjiu 26).The results showed that there were significant differences in the production performance of different varieties of silage-specific corn(P < 0.05).Beinong208 had the highest fresh and dry matter yields,the lowest NDF,ADF,and the higher WSC,CP contents.There was correlation between agronomic characteristics,biological yield,and nutrient compositions of silage-special corn.Fresh and dry matter yields were significantly positively correlated with plant height(P < 0.05).Leaf weight ratio(FW/DM)was highly significantly negatively correlated with DM content(P < 0.01),and was highly significantly positively correlated with WSC content(P < 0.01).There were significant differences in the production performance of different varieties of dual-purpose corn silage(P < 0.05).Dajingjiu 06 has the highest WSC,the lowest NDF,ADF contents,and the higher dry matter yields.There was correlation between agronomic characteristics,biological yield,and nutrient compositions of dual-purpose corn silage.Fresh and dry matter yields and CP content were significantly positively correlated with the number of leaf(P < 0.05).WSC content was significantly positively correlated with stem weight ratio(FW)(P < 0.05).NDF and ADF contents were highly significantly positively correlated with plant height(P < 0.01)2 Fermentation quality,microbial diversity,and aerobic stability of different varieties of silage-special cornThe experiment was conducted to compare the fermentation quality,microbial diversity,and aerobic stability of different silage-special corn varieties with or without lactic acid bacterial inoculants.Each corn variety was treated with the following: untreated corn(CK),inoculating with Lactobacillus buchneri(LB),Lactobacillus plantarum(LP),or Lactobacillus buchneri + Lactobacillus plantarum(LB+LP).The results showed that all treatments in five corn silage varieties were well fermented with low p H value(< 3.90)and high LA(> 80.2 g/kg DM)concentration.Of five varieties,Jingjiu 16 had higher LA,WSC contents,the lowest p H value and ADF content.Inoculants reduced the p H value and AN content,and increased DM and WSC contents of most varieties of corn silage.LB and LB+LP increased the AA content in most varieties of corn silage.There were differences in epiphytic microbial communities among five fresh corn silage varieties,Lactobacillus became predominant genus in 90-d silages.The effects of inoculants on the microbial communities of five varieties of corn silage were different.LB+LP increased the relative abundance of Lactobacillus in Beinong 356.There were significant differences in the aerobic stability of five silage-special corn varieties(P < 0.05).Beinong 208 showed the longest aerobic stability,while Zheng 1 firstly aerobic spoilage.LB significantly improved the aerobic stability of Zheng 1 and Jingjiu 16(P < 0.05).3 Fermentation quality,microbial diversity,and aerobic stability of different varieties of dual-purpose corn silageThe experiment was conducted to compare the fermentation quality,microbial diversity,and aerobic stability of different dual-purpose corn silage varieties with or without inoculants.Each corn variety was treated with the following: untreated corn(CK),inoculating with Lactobacillus buchneri(LB),Lactobacillus plantarum(LP),or Lactobacillus buchneri + Lactobacillus plantarum(LB+LP).The results showed that all of five varieties of corn silage were well fermented with low p H value(< 3.80)and high LA(>73.6 g/kg DM)concentration.Of five varieties,Dajingjiu 06 had the lowest p H value,NDF,and ADF contents.Inoculants reduced the p H value,AN content,and aerobic bacteria population,and increased the contents of LA and WSC of most varieties of corn silage.There were differences in microbial communities among five fresh corn silage varieties,Lactobacillus became predominant genus in 90-d silages.The effects of inoculants on the microbial communities of five varieties of corn silage were different.LP increased the relative abundance of Lactobacillus in Daingjiu 26.There were significant differences in the aerobic stability of five varieties of dual-purpose corn silage(P < 0.05).Dajingjiu 26 showed the best aerobic stability,while aerobic stability of Dajingjiu 06 was the worst.LB significantly improved the aerobic stability of Jingjiu 166,Dajingjiu 06,and Dajingjiu 4059(P < 0.05).4 Comprehensive evaluation of ten varieties of corn silageHeatmap analysis was performed on the production performance,fermentation quality,aerobic stability,and microbial communities of different varieties of corn silage.The results showed that: The production performance,fermentation quality,and aerobic stability of silage-special corn were better than that of dual-purpose corn silage.Principal component analysis was performed on the production performance,fermentation quality,and aerobic stability of all varieties of corn silage.The results showed that: Four treatments of Beinong208 and Dajingjiu 3912 had higher principal component scores with the high production performance,fermentation quality,and aerobic stability.And the principal component scores of CK were higher than that of LB,LP,and LB+LP in Beinong 208 and Dajingjiu3912.Beinong 208 and Dajingjiu 3912 were recommended to be widely cultivated in temperate monsoon climate regions of China.It is recommended that the silage quality of Zheng 1,Jingjiu 16,Jingjiu 166,and Dajingjiu 4059 can be further improved by Lactobacillus buchneri,while Lactobacillus plantarum can be used for ensiling of Yu 23. |
