الفهرس | Only 14 pages are availabe for public view |
Abstract Collectively, from the results of the present study it could be concluded that dietary energy and protein levels affected the growth performance as increased energy levels did not affect body weight gain but decreased feed consumption and improve feed conversion ratio of growing lambs. Increasing the dietary protein levels from 14 to 18% did not significantly improve growth performance parameters. The results could indicate that the protein levels of 16% with 3.4 MCal ME/ kg diets improve growth performance. Dietary energy and protein levels did not significantly affect carcass characteristic parameters regarding the dressing carcass, liver, kidneys, and heart weights and percentages, however, increasing the the energy levels increased the depot fat weight and percentages. The dietary energy did not significantly affect the ruminal total volatile fatty acids and fractionated fatty acids (acetate, propionate and butyrate) or ammonia-nitrogen concentration. On the other hand, increasing the dietary protein increased the ruminal ammonia nitrogen concentration which decreased with time. In conclusion, depending on growth performance and feed cost per kilogram body weight gain, the lambs fed the diet containing 16% crude protein with 3.4 MCal/ Kg provided the best results. |