Twenty growing crossbred male lambs (¾ chios. ¼ ossimi and ½ chios. ½ ossimi) of 15.25 ± 2.00 kg initial average body weight and three months old were divided into four groups. All groups were fed on concentrate feed mixture plus 1% of live body weight wheat straw for 169 days. Four levels (zero, 200g, 400g and 600g) of leucaena hay were used. Final weight and carcass traits were evaluated. Color (L, a, b), proximate composition, pH, acidity, expressible water, water holding capacity, cooking loss, amino acid and minerals contents of meat were determined. Sensory evaluation of cooked meat was also evaluated.The results revealed that, Hindquarter, shoulder, and sets weight were significantly (p ≤ 0.05) different. Moisture, protein, fat and ash content of fresh meat were ranged from 73.72 to 76.23%, 20.06 to 20.80 %, 2.41 to 4.12% and 1.01 to 1.08%, respectively. Expressible water, water holding capacity and pH were significantly (p ≤ 0.05) different. No significant (p ≤ 0.05) differences were found in color (L, a, b), acidity and cooking loss of meat. Amino acids and minerals contents of all meat samples were varied. Cooked meat of group four had the highest scores of tenderness, juiciness, flavor and over all acceptability 4.6, 4.5, 4.4 and 4.5, respectively. This study suggested that the leucaena hay is suitable for lamb feeding. Produced lamb meat had high chemical and sensory quality.

The present study was designed to investigate the effects of partial replacing green guar (Cyamopsis tetragonoloba) forage (GG) and rice straw or guar forage silage (GS) instead of concentrate feed mixture (CFM) on the digestibility, productive and economic performance and blood biochemical constituents of growing lambs. Twenty four weaned of Farafra male lambs 5 months age and weighed in average 16.69 ± 2.65 kg, were used in a feeding trial for 120 days in a complete block design. Animals were divided according to their live body weight into three experimental groups (8 lambs each), Ration 1 (R1) consists of 60% CFM + 40 % rice straw (control), R2: (40% CFM + 40% GGF + 20 % rice straw and R3: (40% CFM + 40% GFS + 20% rice straw). GGF and GFS were used to cover a partial of protein from CFM. The experimental rations fed according to NRC (1985). Results indicate that the apparent digestibility coefficients of all nutrients and feeding value of rations containing (GG) or (GFS) were better (P<0.05) compared to the control ration. Percentage of apparent N-utilization was currently higher (P<0.05) for the guar green forage and guar forage silage (R2 and R3) rations than the control ration (R1). Significant increased (P<0.05) were reported on total feed intakes, total weight gains, average daily gains (ADG) and better feed conversion ratios (FCR) and economic efficiencies for groups R2 and R3 compared with control group. The realized ADG were 198.08 and 185.83 g/day for R2 and R3, respectively, while lambs of the control recorded 177.11 g/day. No significant differences among experimental diets in serum total protein, albumin, globulin, trans-aminase enzymes (AST and ALT), cholesterol, triiodothyronine (T3) and Thyroxin (T4) hormones. It could be concluded that, feeding guar green forage or guar forage silage up to 40% as partial replacement of concentrate feed mixture for Farafra growing lambs rations were recommended. Such rations resulted in superior nutrition, better daily gain, feed conversion and economic efficiency.

his study was conducted to investigate the growth performance of lambs fed sugar beet tops silage (SBTS) with concentrate feed mixture CFM. Forty growing male lambs (20 Frafra and 20 saidi weight 20.19 kg as average) were used in feeding trail. Animals were randomly divided into five similar groups according to their live body weight beside twenty mature rams (45 kg live body weight) were used in digestibility trails. Each groups were fed one of the following diet. (T1), CFM +Wheat Straw control, (T2) , CFM + SBTS supplemented with 0.25 urea /100 kg dry matter of silage unchopped), (T3), CFM + SBTS supplemented with 0.25 urea /100 kg dry matter of silage chopped), (T4), CFM + SBTS supplemented with 0.5 urea /100 kg dry matter of silage un-chopped), (T5), CFM + SBTS supplemented with 0.5 urea /100 kg dry matter of silage chopped). CFM were offered as 3% of live body weight for all groups ,while roughages were fed ad lib. Control T1 had higher (P<0.05) digestibility in CP, CF, EE and TDN compared with treatments containing ureated SBTS chopped or un-chopped, but diets ureated with 0.25% urea chopped or unchopped was better in digestibility than those ureated with 0.5% urea. Rations containing 0.25% urea chopped or un-chopped(T2 andT3) were the best (P<0.05) digestibility in OM, NFE and digestible crude protein (DCP) than rations T4,T5 and control. The values of total nitrogen intake (TNI), fecal nitrogen (FN),urinary nitrogen(UN), total nitrogen excretion(TNE), nitrogen balance(NB) and nitrogen absorption (NAB) in control treatment lower (P<0.05) than other treatments. Total gain and daily gain were reicorded by the rations contain SBTS( U .0250% ) higher than rations contain SBTS (U.0.5%) and control ration . This diferences were insignificant. The significant(P<0.05) higher DM and TDN consumed by lambs fed control ration (T1),but feed intake as DCP has lower than other treatments . Lambs fed T2 and T3, showed the best conversion as DM and TDN, compared with those fed (T1),(T4) and(T5). Therefore, the lowest feed cost and the best weight gain equal the best revenue and better economic efficiency which showed by lambs fed diets containing ureated sugar beet tops T2 flowed by T3, T4, T5 and T1.

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