Avaliacao nutricional de pastagens de capim-elefante e capim-mombaca sob manejo rotacionado em diferentes periodos de ocupacao
Lista, F.-Nunes; Coelho-Da-Silva, J.-Fernando; Vasquez, H.-Maldonado; Detmann, E.; De-Carvalho-Peres, A.-Aurelio
Revista Brasileira de Zootecnia 36(5): 1406-1412
ISSN/ISBN: 1516-3598 Accession: 015105501
Qualitative assessment of elephantgrass (Pennisetum purpureum, Schum. cv. Napier) and mombacagrass ( Panicum maximum, cv. Mombaca) pastures under rotational stocking was performed using the esophageal extrusa technique. Samples of esophageal extrusa were taken at the third, second and first days of the grazing period. The following analyses were determined: DM, CP, EE, OM, lignin (LIG), NDF, ADF, in vitro dry matter digestibility (IVDMD), lag time and degradation rate of carbohydrates, and fractions of the carbohydrates and nitrogenous compounds. The average composition of extrusa samples as a function of the days under grazing were compared through orthogonal contrasts, with subsequent adjustment of regression equations. For IVDMD and LIG, differences were observed just for the mombacagrass. For this species, an increase of 2.57 percentual points in the indigestible fraction ( fraction C) and a reduction of 3.23 percentual points in the potential degradable fraction (B2) of carbohydrates were observed. For the kinetics of degradation, it was found difference just for the momba agrass, showing linear reduction in the rate of degradation of the fibrous carbohydrates. Both the acid detergent insoluble protein fraction and the protein degradable fraction of elephantgrass and momba agrass showed linear decrease with increasing grazing period.