Effect of mineral mixture supplementation on in vitro dry matter digestibility and ruminal metabolites in roughage based diets of sheep.

摘要

An in vitro study was conducted in roughage based rations to record the effect of area specific mineral mixture on dry matter digestibility and ruminal metabolites. A concentrate mixture was prepared using barley (40 parts), mustard cake (35 parts), and wheat bran (23 parts) with ~18% CP. The concentrate mixture was fortified with 0 (T< sub>0), 1.0 (T< sub>1), 1.5 (T< sub>2) 2.0 (T< sub>3) and 2.5% (T< sub>4) area specific mineral mixture and 2.0% (T< sub>5) standard mineral mixture. The different roughage:concentrate mixture/dietary combinations (80:20 (maintenance rations) or 60:40 (productive rations)) were prepared using wheat straw, paddy straw and sorghum stovers as roughage source. These dietary combinations were subjected to in vitro dry matter digestibility with sheep rumen inoculums. Maintenance type of rations contained 6.56 to 7.20% CP and 66.4 to 72.3% NDF, while productive type of roughage based rations contained comparatively more CP (9.31 to 9.90%) and less NDF (57.3 to 58.7%). Average IVDMD was 59.7, 64.8, 64.4, 63.9, 64.5 and 63.3% in T< sub>0, T< sub>1, T< sub>2, T< sub>3, T< sub>4 and T< sub>5, respectively, and the differences were insignificant. A similar trend with respect to ruminal metabolites like pH (6.21 to 6.09), TVFA (9.20 to 9.53 meq/dl) and total-nitrogen (55.13 to 63.10 mg/dl) was observed. However, the type of ration had a significant influence on IVDMD and ruminal metabolites. The productive rations had higher (P<0.05) IVDMD (67.0 vs. 59.9%), TVFA (9.78 vs. 8.93 meq/dl) and total nitrogen (64.7 vs. 55.56 mg/dl) contents when compared with the maintenance type of rations.