M. J. D. Cândido

Chemical and bromatological characteristics of elephant grass silages containing a mango by-product

This study was carried out to evaluate the nutritive value of elephant grass (Pennisetum purpureum, Schum.) silages with the addition of 0, 4, 8, 12 and 16% dehydrated mango (Mangifera indica, L.) by-product (DMB), on the fresh matter basis. A randomized complete design with four replications was used. As experimental silos, 210L plastic drums were used. Dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HCEL), ether extract (EE), total carbohydrates (TC), non-fibrous carbohydrates (NFC), neutral detergent insoluble nitrogen (NDIN, % total N), acid detergent insoluble nitrogen (ADIN, % total N), pH values, ammoniacal nitrogen (% total N), lactic acid, acetic acid, butyric acid and propionic acid levels were determined. The DM, OM, CP, EE, NFC, NDIN, lactic acid and propionic acid levels increased with the DMB addition while the NDF, ADF, hemicellulose, N-NH3/ammoniacal nitrogen levels and the pH values decreased with the DMB addition. The addition of DMB had a quadratic effect on the acetic and butyric acid levels but there was no effect with the addition of DMB on TC and ADIN. The DMB can be used at the ensiling of the elephant grass, because the addition of 8.6% improves the silages fermentative process. However, these silages have low crude protein levels and high contents of ether extract and nitrogen compounds mixed with the fiber (NDIN and ADIN) in the silages, that may damage their use by animals.

Produtividade e composição bromatológica de Panicum maximum cv. Mombaça sob irrigação e adubação azotada

The effects of different irrigation levels and doses of nitrogen (N) on yield, nitrogen use efficiency (NUE) and chemical composition of Mombasa grassxa0(Panicum maximum)xa0were evaluated. The experimental design was randomized blocks in a 2x4 factorial, with three replicates, two water levels (50% and 80% of Class A pan evaporation, ECA) and four levels of N (200, 400, 600 and 800 kg / ha / year). The water depth applied showed similar behaviors regarding NUE, total dry matter yield (TDMY), leaves (DMYL) and stems (DMYS), and levels of neutral detergent fiber (NDF). The nitrogen fertilization influenced positively TDMY, DMYL and DMYS, however, decreased NUE. Crude protein (CP) of the leaves and stems were influenced by the interaction of blades irrigation x nitrogen fertilization. There was a linear effect of N on the PB. The levels of acid detergent fiber (ADF) had negative influence of greater water depth. Concentrations of ADF were reduced by nitrogen fertilization. Irrigation of 50% of ECA, associated with application of 800 kg N / ha / year, showed the best results, considering productivity, chemical composition and water savings.