مصرف اختياري و قابليت هضم گاو دانه و يونجه با روشهاي حيوان زنده وآزمايشگاهي

Voluntary feed intake and digestibility of bitter vetch and alfalfa via in vivo and in vitro methods

In order to determine hitter vetch and vetch and alfalfa digestibility via in vivo and in vitro method, an experiment was conducted with 16 Ghezele wethers. In this experiment the digestibility was determined through regression equations correlation coefficient was calculated between in vivo and in vitro methods. The chemical analysis of alfalfa and bitter vetch were determined. In in vivo method, four treats containing 0, 25. 50 and 75 percent of bitter vetch were considered with alfalfa based diet, In this method, digestibility of all nutrients except crude fiber and ADF were increased significantiy with increased bitter vetch levels but a significant difference was not observed between crude protein digestibilites in rations containing 50 and 75% of hitter vetch. Relationship between hitter vetch levels and all of digestible nutrients waslinear and its r, was 98%. In the method of in vitro, dry matter, organic matter and organic matter per dry matter of ration were increased with increasing of bitter vetch ratio from zero to 100% but there was not any significant difference between organic matter and organic matter per dry matter between zero and 25% of bitter vetch levels. The correlation coefficients between retween results of in vivo and in vitro methods on dry matter, organic matter and 1)-value for alfalfa were 99, 99 and 97 and bitter vetch was 97, 98 and 96 respectively. Among treatments, feed containing 50% alfalfa and 50% bitter vetch had the highest voluntake, But metabolizable energy from intake containing 25% alfalfa and 75% bitter vetch was the highest. It is worth mentioning that concentration of metabolizahie energy increased with increasing of bitter vetch ratio.