Determine the Proper Level of Yeast with Different Levels of Roughages to Improve the Nutritive Value of Lamb's Ration

The aim of this study was to evaluate the effects of supplemented two levels of yeast culture (YC) to two rations of different roughage levels on animal performance, nutrient digestibility, nitrogen balance, nutritive value and rumen fermentation of growing lambs. Sixty Ossimi male lambs of an average being 37.5Kg body weight and 9 months age were randomly assigned to six nutritional groups. Animals were fed two basal rations differ in roughage ratios (Control 1 or 2) without supplementation or supplemented with 0.1 or 0.2% dry yeast containing 10(8) cells of Saccharomyces cerevisiae per gram (Yea-Sacc(1026)). The growth experiment lasted 120 days. A digestion trail was carried on and samples of rumen liquor were collected at the end of the growth experiment. The results showed that addition of YC to the basal ration increased DMI, TDNI, DCPI, feed conversion ratio and did significantly (P<0.05) improve lambs average daily gain (ADG). On the other hand, YC supplementation improved digestion coefficients of DM, OM, CP and CF. Nitrogen balance, TDN and DCP also significantly (P<0.05) increased by the addition of YC. Ruminal pH value increased (P<0.05) and ammonia concentration decreased (P<0.05) for in animals fed YC supplemented rations compared to the control rations. However, total VFA's concentration not significantly affected by YC supplementation. Supplementation of YC to control 2 of higher roughage content significantly (P<0.05) increased acetate concentration and decreased of propionate concentration in rations 5 and 6 compared with other rations. While, the butyrate concentration were significantly (P<0.05) decreased with supplement control ration 1 and 2 by both two levels of YC (rations 3, 4, 5, and 6). It could be concluded that addition of YC to sheep rations containing different levels of roughages improved growth performance, crude protein and crude fiber digestibility, nitrogen balance and some rumen parameters. [Sawsan, M. Gad, Tawila, M. A., Abou Ward, G. A., Salama R. and Soad El-Naggar. Determine the Proper Level of Yeast with Different Levels of Roughages to Improve the Nutritive Value of Lamb's Ration. Life Sci J 2012;9(3):1773-1780] (ISSN:1097-8135). http://www.lifesciencesite.com. 256