Studies on the rumen degradation kinetics and utilization of apple pomace

Abstract

Abstract Apple (Malus communis) pomace contained 4·72, 20·5, 3·22, 69·0 and 2·60% crude protein (CP), Crude fibre (CF), ether extract (EE), nitrogen free extractives (NFE) and total ash and 40·8, 29·9, 10·9, 15·9 and 14·0% neutral detergent fibre (NDF), acid detergent fibre (ADF), hemicellulose, cellulose and lignin, respectively. Rapidly soluble, degradable fraction and 48 h digestibility values for DM were 18·9, 68·8 and 83·5%, respectively. Potential extent and lag time of cell wall digestion was 74·9% and 5·82 h, respectively. The fractional rate constants for DM, cell wall, ADF and hemicellulose digestion were 0·0589, 0·0574, 0·0546 and 0·0624 per h respectively. Rumen available carbohydrate was 83·3% and the estimated ATP and microbial matter production were 3·17 mol and 33·3 g per 100 g DM, respectively. Packed volume, solubility and water-holding capacity were 1·90 ml/g, 42·3% and 3·20 ml/g, respectively. Digestibilities of DM, CP, CF, NFE and EE in animals fed conventional ration and urea-supplemented apple pomace were 57·5 and 56·2; 62·7 and 59·8; 49·0 and 52·1; 64·0 and 65·4; and 56·6 and 43·1%, respectively, and the corresponding values for NDF, ADF, hemi-cellulose, cellulose and lignin digestibilities were 53·9 and 48·7; 44·5 and 49·1; 64·2 and 47·7; 51·0 and 55·9; and 10·7 and 22·0%, respectively. Animals in both treatments exhibited positive nitrogen balances. The results suggest apple pomace to be a good energy source and also feasible as the only supplement to straw for ruminants when supplemented with urea.