Nutritive value of the elephant-grass obtained on different cut ages

Abstract

The present work aimed to determine the chemical composition, the parameters of the dry matter (DM) and neutral detergent fiber (NDF) in situ degrability, the MS (IVDMD) in vitro dry matter digestibility and the content of total digestible nutrients (NDT) of grass-elephant obtained in different cut ages, in rainy season. The grass-elephant was submitted to the cut at the ages of 30, 45, 60, 75, 90 and 105 days, from December to March. The samples were analyzed for dry matter (MS), crude protein (PB), ash, ether extract (EE), total carbohydrates (CT), neutral detergent fiber (NDF) and acid (FDA), indigestible NDF (INDF) and insoluble protein in acid detergent (ADIP). Additionally, the samples were weighted in bags of nylon, incubated in the rumen of three bovine canulated, and the residues were analyzed for DM and NDF residual. Subsequently, it were submitted to in vitro incubation with liquid ruminal and solution of acid pepsin for dry matter in vitro digestibility (IVDMD)determination, of which values were utilized for content of total digestible nutrients (NDT) estimation. The content of CP was reduced in a linear way by the advancement of the cut age, while the contents of NDF, ADF, INDF and ADIP increased. The fraction “a” of the DM was reduced and the NDF I fraction was increased with the cut age advancement. The IVDMD and TDN presented quadratic behaviors (P<0,05), in function of cut age , with maximum values of 69.00% and 57.21%, to the ages of 19.64 and 48.98 days, respectively.