Research On Influence Of Key Factors And Quality Characteristics Of Oats Silage In Alpine Regions

Oat（Avena sativa L.）is an important forage resource in alpine regions,and its preparation into silage to solve the problem of unbalanced seasonal supply of forage is of great importance to the development of livestock industry in alpine regions.This experiment was designed to investigate the key factors,optimum parameters and additives affecting oat silage in alpine regions.This study consists of two parts,experiment 1 investigates the key factors and optimum parameters affecting oat silage in alpine regions.A three-way quadratic regression generalized rotational combination design was used with temperature,moisture content,and compaction density as the test factors,and different levels of temperature（15°C,20°C,27.5°C,30°C,35°C）,compaction density(300 kg-m^-3,380 kg-m^-3,450 kg-m^-3,520 kg-m^-3,600 kg-m^-3),and moisture content（35%,44%,58%,71%,and 80%）were tested for intercropping silage,and samples were taken at 25 d,50 d,and 75 d.Experiment 2 investigated the effect of different additives（cellulase,heterofermentative lactic acid bacteria,homofermentative lactic acid bacteria）on oat silage in alpine regions at different moisture contents（35%,44%,58%,71%,80%）based on the optimal compaction density and temperature,sampled after 60 d of silage.All of the above treatments were evaluated comprehensively by analyzing the sensory evaluation,nutritional and microbiological indicators after silage after sampling.The results showed that.（1）Compaction density,temperature and moisture content all had significant effects on oat silage quality,with the three factors affecting oat silage in the following order of magnitude:compaction density>temperature>moisture content.Fermentation of oat silage in alpine regions at a moisture content of 58%-65%,a compaction density of 490 kg·m^-3-520 kg·m^-3 and a temperature of 27.5°C-31°C is most suitable.（2）The p H of silage gradually decreased with the extension of fermentation time,the content of mold and yeast also decreased significantly after 50 d of silage,the content of crude protein was the lowest at 50 d of silage,the content of acidic detergent fiber and dry matter showed a decreasing trend with the extension of silage time,and decreased significantly at the later stage of silage;the content of water-soluble carbohydrates decreased with the extension of silage time.（3）Shaped lactic acid bacteria additives excel in the preservation of dry matter, crude protein,lactic acid bacteria,improvement of sensory evaluation,and p H reduction,The addition of heterogeneous lactic acid bacteria additive increased the lactic acid bacteria content by 80%compared to CK and decreased the p H value by5.26%compared to CK group.Cellulase performed well in reducing the content of neutral and acidic detergent fibers with 2.90%and 3.25%,respectively,and all three additives significantly increased the content of water-soluble carbohydrates（4）Both Lactobacillus plantarum and cellulase were effective in improving the quality of oat silage at different moisture contents,but when the moisture content was35%and 80%,all three additives were significantly less effective than the other treatment groups.