| This paper takes rice straw,Zizania latifolia,alfalfa,king grass and pennisetum giganteum as the research objects,the objective of this study is to evaluate effects of different silage densities on the fermentation quality and aerobic stability of rice straw,zizania latifolia,alfalfa,king grass and pennisetum giganteum.In order to determine the appropriate silage density,it will provide a reference plan for the setting of silage density in the rice,Zizania latifolia,alfalfa,king grass and pennisetum giganteum.The experiment consists of five parts:1 The effect of silage density on the fermentation quality and aerobic stability of rice straw silageThe objects of this study is to explore the effects of silage densities on the fermentation quality and aerobic stability of rice straw silage.The experiment has three density gradients:low density(500 g·L-1)and medium density(600 g·L-1)and high density(700 g·L-1).The silos from each treatment were opened and analyzed at fermentation（3,5,7,14,30,45day）.At the same time,the rice straw silage for 45 days was exposed to the air,and the temperature changes were monitored during the aerobic exposure.Sampling and analysis were taken on the 2,4,and 6 days of exposure to assess the aerobic stability.The results showed that increasing the silage density improved the fermentation quality and the aerobic stability of rice straw silage.Compared with the low-density group,the medium-density and high-density groups had reduced dry matter and water-soluble carbohydrate losses,increased lactic acid content,and decreased p H,acetic acid content,and ammonia nitrogen/total nitrogen.During aerobic exposure,the p H value of the low-density and medium-density groups was lower than that of the high-density group,and the acetic acid content was higher.The number of yeasts in the low-density and medium-density groups was lower than that in the high-density group 4 days before aerobic exposure.It shows that the aerobic stability of the low-density and medium-density groups is better than that of the high-density group.Considering comprehensively,medium density(600 g·L-1)has the best effect on improving the fermentation quality of rice straw silage and increasing its aerobic stability.2 The effect of silage density on the fermentation quality and aerobic stability of water bamboo silageThis study was conducted to assess the effects of ensiling densities on the fermentation quality and aerobic stability of sheath and leaf of water bamboo,and provide a theoretical basis for selecting suitable silage density for sheath and leaf of water bamboo silage production in practice.The experiment was designed by three density gradients(low density(650 g·L-1),medium density(750 g·L-1),high density(850 g·L-1).The laboratory silos were opened on 3,5,7,14,30 and 45 days respectively,and the fermentation quality was analyzed.At the same time,the water bamboo silage for 45 days was exposed to the air,and the temperature changes were monitored during the aerobic exposure.Sampling and analysis were taken on the 2,4,and 6 days of exposure to assess the aerobic stability.The results showed that the interaction between ensiling density and days had a significant（P<0.05）impact on water-soluble carbohydrates,lactic acid contents and the ratio of lactic acid to acetic acid.Compared with low density treatment,the dry matter,lactic acid,water-soluble carbohydrate content,and lactic acid/acetic acid were higher in the medium and high density groups,while the ammonia nitrogen/total nitrogen and p H were lower.During aerobic exposure,the p H,ammonia nitrogen/total nitrogen,aerobic microorganisms and yeasts of the medium-density and high-density groups were lower than those of the low-density group,and the acetic acid content was higher than that of the low-density group.To sum up,increasing the silage density can effectively improve and improve the fermentation quality and aerobic stability of water bamboo silage.Compared with low density,medium density and high density groups have better aerobic stability.Among them,the medium density group(750 g·L-1)had the best effect.3 Effects of silage density on the fermentation quality and aerobic stability of alfalfa silageThe effects of ensiling density on fermentation quality and aerobic stability of alfalfa were studied.Three density gradients were set up in the experiment,namely low density(600g·L-1),medium density(700 g·L-1),and high density(800 g·L-1),The laboratory silos were opened on 3,5,7,14,30 and 45 days,and the fermentation quality was analyzed.At the same time,the alfalfa silage for 45 days was exposed to the air,and the temperature changes were monitored during the air exposure.Sampling and analysis were taken on the 2,4,and 6 days of exposure to assess the aerobic stability.The results showed that increasing the silage density reduced the dry matter loss of alfalfa silage,reduced the ammonia nitrogen/total nitrogen and p H,and increased the lactic acid content.However,the p H of each treatment group in this experiment failed to fall below 4.2 which is required for conventional silage.Failed to meet the requirements for silage preservation.During the aerobic exposure,no significant aerobic spoilage occurred in each treatment group.This may be due to the low water-soluble compounds and high buffering energy of alfalfa.Simply increasing the silage density cannot reduce the p H.Therefore,only increasing the silage density cannot solve the problem that alfalfa is not easy to silage successfully,and other measures are needed.4 The effect of silage density on the fermentation quality and aerobic stability of king grass silageThis experiment was conducted to investigate the effects of different silage density on fermentation quality and aerobic stability of king grass silage.The experiment has three density gradients,namely low density(700 g·L-1),medium density(850 g·L-1)and high density(1000 g·L-1).The laboratory silos were opened on 3,5,7,14,30 and 45 days respectively,and the fermentation quality was analyzed.At the same time,the king grass silage for 45 days was exposed to the air,and the temperature changes were monitored during the aerobic exposure.Sampling and analysis were taken on the 2,4,and 6 days of exposure to assess the aerobic stability.The results showed that increasing the ensiling density reduced the loss of dry matter and water-soluble carbohydrates,lowered the p H and ammonia nitrogen/total nitrogen.The content of lactic acid in medium density and high density groups was significantly higher than that in low density group 5 days before ensiling.With the extension of the silage time,the acetic acid content gradually increased,and the acetic acid content in the medium density and high density groups was lower than low density group.During aerobic exposure,the p H and ammonia nitrogen/total nitrogen of the low-density group were lower than the other two treatment groups,and the number of aerobic microorganisms and yeasts in the low-density treatment group was lower than that of the high-density group.It shows that the low density group has better aerobic stability.Considering the fermentation quality and aerobic stability of silage,it is more appropriate to set the king grass ensiling density to 700 g·L-1.5 The effect of silage density on fermentation quality and aerobic stability of pennisetum giganteum z.x.lin silageThe purpose of this study is to investigate the influence of ensiling density on the fermentation quality and aerobic stability of pennisetum giganteum z.x.lin.The experiment set three density gradients,namely low density(750 g·L-1),medium density(900 g·L-1)and high density(1050 g·L-1).The laboratory silos were opened on 3,5,7,14,30 and 45 days respectively,and the fermentation quality was analyzed.At the same time,the pennisetum giganteum z.x.lin silage for 45 days was exposed to the air,and the temperature changes were monitored during the aerobic exposure.Sampling and analysis were taken on the 2,4,and 6days of exposure to assess the aerobic stability.The results showed that as the silage density increased,the loss of dry matter and water-soluble carbohydrates decreased,and the ammonia nitrogen/total nitrogen decreased,but the ammonia nitrogen/total nitrogen of the low-density treatment group reached 100 g·kg-1 DM on the 14 day of silage.The p H of the medium density and high density groups was lower than that of the low density group,the lactic acid content was higher,and the acetic acid content before silage was lower than that of the low density group in the 30 days.During the aerobic exposure,the medium-density group had the longest aerobic stability time.During aerobic exposure,the p H and ammonia nitrogen/total nitrogen,yeasts and aerobic bacteria of the medium density and high density groups were lower than those of the low density group.It shows that the aerobic stability of the medium density and high density group is better than that of the low density group.Considering the fermentation quality and aerobic stability of pennisetum giganteum z.x.lin silage,it is recommended that the density is 900 g·L-1. |
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