Evaluation of dried grape by-product as a tanniniferous tropical feedstuff

The present study was carried out to determine the chemical composition, digestibility and degradability of dried grape by-product (DGB). The data was analyzed using completely randomized design. The mean values of the dry matter (DM), organic matter (OM), crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), total phenol (TP) and total tannin (TT) for DGB were 884.5, 926, 63.5, 255, 259, 67, and 52.3 g/kg DM, respectively. The DM and OM digestibilities were not affected when up to 450 g/kg of dietary alfalfa was replaced by DGB, but CP, NDF, and ADF digestibilities were reduced by the addition of DGB to diets (P<0.05). The concentrations of VFA and NH3-N were reduced when alfalfa was replaced with up to 450 g/kg DGB (P<0.05). The effective degradability of DM and CP was 0.638 and 0.701 based on in situ fermentation. Results showed that adding DGB reduced CP digestibility and ruminal NH3-N and VFA production.