Study On The Quality Of Mixed Silage Of Forage Rape With Alfalfa Or Myriophyllum

China is rich in rape resources,among which forage rape has been widely popularized nationwide because of its low cost and high feeding value,but there exist some problems of hard texture and poor palatability when used as feed.Alfalfa is high in protein content,and has a large planting area and high yield in the south,but its moisture content is high,which is not conducive to storage under conventional conditions.Myriophyllum spicatum is widely grown in ponds and rivers in the north and south of China.It is a potential forage resource with fast growth and large biomass,but its utilization rate is low at present.In this study,forage rape,alfalfa and m.spicatum were used as silage materials.Mixed silage method was adopted to explore the effects of different mixing ratios and additives（urea and molasses）on the quality of mixed silage,and the best mixing ratio and additive application scheme were screened out to improve the utilization rate of agricultural resources and provide scientific technical parameters for the practical application of mixed silage.In this study,the suitable proportion of mixed silage between forage rape and alfalfa or m.spicatum was initially explored.Forage rape was mixed with alfalfa or m.spicatum according to different fresh weight mass ratios,the changes of nutritional components and fermentation indexes of the mixed silage were analyzed,and exploring the digestion of feed nutrients after fermentation.And finally get the appropriate proportion of mixed silage.The results showed that:（1）Compared with the mixed silage group,the overall quality of single silage of forage rape,alfalfa and m.spicatum was poor.（2）When the mixed silage ratio of forage rape and alfalfa was 3:7,the overall quality of feed was better:the contents of water soluble carbohydrates(116.30 g·kg^-1DM)and crude protein(152.29g·kg^-1DM)increased significantly after 5 days of fermentation（P<0.05）.At the end of fermentation,the p H value（3.95）and ammonia nitrogen/total nitrogen（4.61%）were significantly lower than those in control group,lactic acid(96.46g·kg^-1DM)content was significantly higher（P<0.05）,the nutrients in vitro digestibility and membership function mean value（0.76）were higher.（3）The overall feed quality was better when the ratio of forage rape and m.spicatum silage was 7:3:after silage,the contents of dry matter(391.45g·kg^-1DM)and crude protein(118.20g·kg^-1DM)were significantly higher（P<0.05）,the p H value（4.56）,ammonia nitrogen/total nitrogen（3.17%）and butyric acid content(0.53g·kg^-1DM)were lower,and the membership function mean value was the highest（0.84）.In the second stage of this study,the better mixed silage of forage rape and alfalfa,forage rape and m.spicatum were selected to improve the quality to expore the effects of different additives on the quality of mixed silage.The results showed that:（1）The effect of adding compound additives（0.3%urea+3%molasses）to the mixed silage of forage rape and alfalfa was relatively good:during the whole silage process,the loss of dry matter was relatively low.The water soluble carbohydrates(43.88 g·kg^-1DM),lactic acid/acetic acid（4.32）,lactic acid content(145.95 g·kg^-1DM)and dry matter digestibility（74.21%）were significantly higher than those in control group（P<0.05）after 60 days of silage.（2）The overall feed quality of mixed silage of forage rape and m.spicatum was better when adding3%molasses:during the whole silage period,water soluble carbohydrates content maintained a high level,and the contents of neutral detergent fiber and acid detergent fiber were lower.After 60 days of fermentation,the contents of ammonia nitrogen/total nitrogen（4.67%）and butyric acid(0.58g·kg^-1DM)were significantly lower than those in other additive treatment groups（P<0.05）.The lactic acid content(63.21g·kg^-1DM)and in vitro digestibility of dry matter（55.28%）and neutral detergent fiber（47.15%）were significantly increased（P<0.05）.Based on the above results,the mixed silage of forage rape mixed with alfalfa or m.spicatum in a certain proportion and using specific silage additives have good nutritional quality and fermentation quality,and the in vitro digestibility of nutrients can be improved to some extent.In this study,the best silage effect were obtained when forage rape and alfalfa were mixed at a ratio of 3:7 with compound additives（0.3%urea+3%molasses）and forage rape and m.spicatum were mixed at a ratio of 7:3 with 3%molasses.