| Tibet is located in the hinterland of the Qinghai-Tibet Plateau,is an important plateau pasture in China.Tibet’s unique climate environment and geographical location restrict the production of forages in its alpine regions,and become a key factor affecting the development of animal husbandry.Silage forage can retain the nutrients of the fresh grass to the greatest extent,and improve the palatability,which is the most effective way to solve the shortage of forage in winter and spring in Tibet.Affected by the high and cold environment,the probability of success of silage production is lower in Tibet,and a scientific system of silage production has not been formed.In order to solve the problem of oat storage,and improve the quality of oat silage in different altitude regions in Tibet,this study took the Qinghai 444 oats planted in Qunipa,Sibu and Naqu as experiment material,and analyzed the influence of altitude environment on oat silage.Treated oat silage with formic acid,urea,EM compound bacteria and corn flour to explore ways to improve the quality of oat silage at different altitudes.The main results and conclusions of this study are as follows:1.The fermentation quality and microbial characteristics of oat silage at different altitudes.The dominant bacteria phylum in the raw materials of Qinghai 444 oat was Proteobacteria.After ensiled,the dominant bacteria phylum of oat silage in Naqu became Firmicutes,while in the other two regions the dominant bacteria phylum were also Proteobacteria.Compared with the raw materials,the contents of water soluble carbohydrate and neutral detergent fiber were reduced in each group after ensiled,and the contents of crude protein was increased only after ensiled for 60 days.Qunipa and Sibu oats reduced the contents of dry matter after ensiled all time,and Naqu reduced only ensiled 60 days.The p H value of Sibu oats was the lowest after ensiled,but the contents of propionic acid and butyric acid were higher than that of oats in other altitude areas,and the contents of butyric acid was slightly higher than the standard of high quality silage when ensiled 30 days.The contents of lactic acid and the abundance of acid-producing strains in Naqu oat silage at 60 days were significantly higher than that in other Treatments(P<0.05),and the main strains were Lactobacillus,Enterococcus and Leuconostoc,and the Alpha diversity indexes were also higher than other silage treatment groups.2.The fermentation quality and microbial characteristics of Tibetan oat at different altitude silage regions.With the changes of silage regions at different altitudes,the nutrient composition,fermentation quality and microbial characteristics of oat silage have changed significantly.The value of p H of Qunipa and Sibu oats decreased after ensiled in Naqu,and the contents of ammonia nitrogen,propionic acid and butyric acid were significantly reduced(P<0.05),while the contents of lactic acid was significantly increased(P<0.05).The dry matter content of Sibu oats after ensiled in Naqu was significantly reduced(P<0.05),and the acetic acid content was significantly increased(P<0.05).When the Naqu oats ensiled in different regions,the crude protein content increased significantly(P<0.05),while the contents of ether extract and lactic acid decreased significantly(P<0.05),and the dominant bacteria for fermentation were Lactobacillus,and the relative abundance of Lactobacillus decreased significantly after ensiled in different regions(P<0.05).The dominant bacteria of Qunipa and Sibu oat silage after fermented in different regions were Hafniaferobacterium.3.Additives to improve the fermentation quality of oat silage at different altitudes in Tibet.From the comprehensive evaluation method of organic acids and ammonia nitrogen and the Kaiser evaluation method,it can be known that the formic acid scores of Qunipa and Sibu oats were the highest,and the conventional silage(CK)scores of Naqu oat silage was the highest.Treated with formic acid significantly increased the contents of dry matter and water soluble carbohydrate in oat silage(P<0.05),and significantly reduced the contents of ammonia nitrogen and organic acids(P<0.05),and lowered the value of p H of oat silage to below 4.2.Treated with corn flour significantly increased water soluble carbohydrate contents of Qunipa and Sibu oats(P<0.05),significantly increased the crude protein and acetic acid contents of Naqu oats(P<0.05),and significantly reduced the value of ammonia nitrogen to total nitrogen(P<0.05).It was concluded that there were significant differences in oat silage due to different sources and ensiled regions.The fermentation quality of high altitude oats was better than low altitude oats.Low altitude oats have improved the quality of silage when ensiled in Naqu,where the altitude is more higher.The high altitude environment of Tibet was conducive to the reproduction of Lactobacillus,which can effectively inhibit harmful bacteria and improve the quality of silage.Formic acid treatment can effectively improved the quality of low-altitude oat silage,and Naqu oat conventional silage(CK)had the best quality. |
PDF Full Text Request