Características fermentativas, composição química e fracionamento de carboidratos e proteínas de silagem de capim-elefante emurchecido ou com adição de torta de mamona

Abstract

The experiment was conducted to evaluate the concentrations of ammonia nitrogen, hydrogen potential, the losses of deriving the fermentative process, nutritional value, the fractioning of carbohydrates and protein the elephant grass silage wilted or not containing castor bean meal. The experimental design was completely randomized, with five treatments and with four replications: elephant grass wilted; elephant not wilted; elephant grass more castor bean meal (6%); elephant grass more castor bean meal (12%) and elephant grass more castor bean meal (18%), the coproduct was added with base on natural matter. We adopted a specific mass of 600 kg/m3. The silage containing 18% castor bean meal showed higher (P<0.05) pH (4.8). High level of ammoniacal nitrogen was observed in the silage grass not wilted (12.8% N-total). The castor bean meal was effective in reducing (P<0.05) losses to by effluent and total, providing a higher rate of recovery of dry matter. Also, was efficient in increasing (P<0.05) the levels of DM, ash, crude protein e lignin. Already for organic matter, acid detergent insoluble nitrogen, total digestible nutrients, neutral detergent fiber, acid detergent fiber, cellulose and total carbohydrate decreased (P<0.05) with increasing doses of the castor bean meal. For the carbohydrate fractioning, there was no difference (P>0.05) among the silages with additives for fractions A+B1, B2 and C. For the protein fractioning, the fractions A and C decreased (P<0.05) with increase of the inclusion of castor bean meal, differently, of the fraction B1+B2 which increased. The castor bean stands out as a good additive in silage of elephant grass to reduce moisture and improve the fermentation characteristics of silages also was effective in increasing the protein value of silages, especially when using the dose 18%.