Effects Of Wheat Bran And Urea Supplementation Ratio On Mixed Silage Quality Of Four Elephant Grass Varieties

Elephant grass is a common herbage with high yield in southern China,which wastes a lot of resources due to the lack of good preservation and utilization methods.In order to solve the problems of difficult preservation and resource waste of elephant grass,this study took(Pennisetum americanum × P.Purpureum)× P.Purpureum schum.cv.Guimu No.1,P.purpureum Schumab cv.Red,P.giganteum z.x.lin and P.purpureum Schum.cv.Gui Min Yin as experimental materials.A single factor test was set for the mixed silage with 5wheat bran supplemental levels(0,5%,10%,15%,20%)and 4 elephant grass varieties and 5urea supplemental ratios(0,0.15%,0.30%,0.45%,0.60%)and 20% wheat bran.There were40 treatment groups with 5 replicates in each treatment.All indicators were measured by opening the package,and sensory evaluation,fermentation quality,nutritional quality and aerobic stability were analyzed to explore the effects of different wheat bran and urea supplemental ratios on the mixed silage quality of the four elephant grass varieties.The results showed that:(1)four elephant grass varieties add wheat bran mixed silage were significantly improved the content of dry matter,crude protein content of silage,aerobic stability and relative forage value,significantly(P < 0.05)reduced crude fibre,neutral detergent fiber,acid washing fiber content,wheat bran adding ratio is higher,the more obvious;The fermentation quality of mixed silage with wheat bran was not ideal for the four elephant grass varieties.Compared with the silage of elephant grass alone,the p H value increased.Except for(Pennisetum americanum × P.Purpureum)× P.Purpureum schum.cv.Guimu No.1,P.purpureum Schum.cv.Gui Min Yin,P.purpureum Schumab cv.Red,P.giganteum z.x.lin and wheat bran,the content of lactic acid decreased and the ratio of ammonia nitrogen to total nitrogen increased after mixed silage.The results showed that the silage quality of(Pennisetum americanum × P.Purpureum)× P.Purpureum schum.cv.Guimu No.1,P.purpureum Schumab cv.Red,P.purpureum Schum.cv.Gui Min Yin and P.giganteum z.x.lin mixed with 15%,20%,20% wheat bran was the best.(2)Different proportion of urea supplementation had no significant effect on the sensory evaluation of mixed silage of four elephant grass varieties and wheat bran(80% :20%).When urea was added to mixed silage of four elephant grass varieties and wheat bran,p H value,ammonia nitrogen/total nitrogen increased significantly,and fermentation quality decreased;Adding urea significantly(P < 0.05)increased the crude protein content of the mixed silage,improved the aerobic stability,and decreased the acid detergent fiber of P.purpureum Schum.cv.Gui Min Yin mixed silage.The addition of urea and wheat bran mixed silage crude fiber,neutral detergent fiber,acid detergent fiber and acid detergent lignin did not significantly reduce the effects of(Pennisetum americanum × P.Purpureum)× P.Purpureum schum.cv.Guimu No.1,P.purpureum Schumab cv.Red and P.giganteum z.x.lin.Through the comprehensive analysis of rank ratio,it was concluded that the best silage quality was obtained by adding 0.45%,0.15%,0.15% and 0.60% urea to(Pennisetum americanum × P.Purpureum)× P.Purpureum schum.cv.Guimu No.1,P.purpureum Schumab cv.Red,P.giganteum z.x.lin Schum.cv.Gui Min Yin respectively.