Effect of mineral mixtures supplementation on in vitro dry matter digestibility of grass-protein dietary regimens.

摘要

This study was conducted to optimize the level of mineral supplementation for enhanced grass-protein diet digestion under in vitro conditions. Dietary combinations were prepared by mixing grass with different protein sources to attain 11-12% crude protein (CP) level in the formulated ration. The ratios of grass to cottonseed cake (CSC), groundnut cake (GNC), mustard cake (MSC) and linseed cake (LSC) were 70.10:29.80, 80.50:19.50, 75.50:24.50 and 63.00:37.00, respectively. The dietary combinations were supplemented with different levels of mineral mixtures: T0 (control); T1 (1.0%); T2 (1.5%); T3 (2.0%); and T4 (2.5%). The highest and lowest CP contents were observed in GNC (39.20%) and MSC (24.50%), respectively. CSC had the highest contents of neutral detergent fibre (NDF), acid detergent fibre (ADF) and cellulose (50.9, 35.3 and 25.0%, respectively). The highest calcium and phosphorus concentrations were observed in MSC (0.58 and 1.12%, respectively). CSC had the highest contents of magnesium (0.806%) and potassium (0.94 ppm). Copper was comparable among the protein sources. Zinc (38.85 ppm) and cobalt (0.85 ppm) contents was higher in CSC than in the other protein sources. The in vitro dry matter digestibility (IVDMD) of grass-MSC and grass-GNC was significantly higher than that of other grass-protein combinations. The IVDMD of grass-LSC and grass-CSC was significantly higher at 48 h than at 24 h. The mean IVDMD of grass-protein sources was higher in T2, T3 and T4 than in T0 at 24 and 48 h of incubation. Supplementation of mineral mixture at 1.5-2.5% level improved the IVDMD of grass-protein diets in sheep inoculum.