Small silo study was conducted to determine the ensiling time and the proportion of cattle wastes to different straws necessary for optimum fermentation. The milking cow wastes were ensiled with wheat, rice and lentil straws. The proportions of waste to straw in the silage were 25, 50 and 75% on dry matter (DM) basis. The duration of ensiling was 4, 5, 6 and 7 weeks. Results indicated that after 7 weeks of ensiling, the pH value reached to a constant level. Also, with increasing the wa proportion the change in the pH values were narrow. In vitro CP and DM digestibilities increased with increasing time of ensiling and proportion of waste. All total and fecal coliforms, and salmonella were disappeared in all mixtures after 4 weeks of ensiling. Digestibility and growth studies were carried out to determine digestibility and growth performance of lambs fed diets containing waste silage prepared from 55, 30, 10 and 5% of rice straw, cattle waste, berseem and molasses, respectively. Three diet treatments (1) control diet A, (2) 13.2% waste diet B and (3) 27.3% waste diet C in DM basis were prepared for digestibility and growth studies. Nine of one year old, Ossimi rams and twenty four, 8 months old, lamb (12 females and 12 males) were used in digestibility and growth studies respectively. Qudratic effects of digestibility were noticed when waste silage was increased from 0 to 27.3% in almost all nutrients. Crude protein digestibilities in diets B and C were about 1.76 and 0.3 times that of diet A respectively. In both males and females the average daily gain was remarkably higher in diet B than diet C which was also higher than the control. The average DG was significantly higher in males than females (P<.05). Differences in DFI was not significant but it was numerically higher in females than males. The relative feeding cost for producing one kg of DG was about 27% lower for males in both diets B and C than diet A, while it was 33.5 and 30% lower in diets B and C respectively, for females, than diet A. It could be concluded that cattle waste can be ensiled with different roughages and fed to lambs without adverse effects.