Abstract
Twenty female Rahmani lambs with an average initial body weight 31.01 +/- 0.68 kg were randomly divided into four similar groups (5 in each group). To receive one of the tested rations, Ration1 containing 50% concentrate feed mixture 1 plus 50% berseem hay as a control ration. In rations 2 and 4, 50% of berseem hay was replaced by dry sugar beet tops. While, in rations 3 and 4, 50% energy ingredients (yellow corn grains, wheat bran and rice bran) were replaced by dry sugar beet pulp in concentrate feed mixture 2. Ration 3 had significantly (P<0.05) the highest digestibility coefficient of all nutrients followed by rations 4 and 2, while, while ration 1 had the lowest values. Digestible crude protein had nearly the same trend, but total digestible nutrients and digestible energy were significantly higher in ration 3 compared with the other rations. A logarithmic scale of acidity or basicity of rumen liquor were nearly similar for all the different groups. Dry sugar beet pulp in rations 3 and 4 showed significantly the higher concentrations of total volatile fatty acids and ammonia nitrogen compared to the other rations. Dry sugar beet pulp increased dry matter, total digestible nutrients, digestible crude protein and digestible energy, but tended to decrease with dry sugar beet tops compared with control group. Growth rate and feed conversion were significantly higher (P<0.05) for lambs fed ration 3 compared with the other rations. Lambs fed ration 3 recorded significantly the highest net revenue and economic efficiency.