Abstract
The study was carried out at the farm located at the Animal Production Farm, College of Agriculture, University of Tikrit for a period of 70 days excluding 14 days as an adaptation period (from 8ᵗʰ October to 16ᵗʰ of December 2020). The aim of this study find alternative diets for fattening Awassi lambs in the northern region and improved protein of barley. Sixteen Awassi lamb were used, aged 5-6 months, with an average starting body weight of 26.2 ± 0.3 kg. Four formulation diets were randomly allocated to four groups of animals. Group one ( control) 98% barley, Group two (88% barley, 5% soybean meal, 5% vegetable fat), Group three (83% barley, 10% soybean meal, 5% vegetable fat), Group four ( 78% barley, 15% soybean meal, 5% vegetable fat). All the experiment diets were supplemented with 1% salts and 1% vitamins and minerals. The lambs were fed concentrate feed at 3% of live body weight on a dry matter basis with 100 grams of roughage (straw) day/lamb. The results showed that animals in group 2 (T2), group3 (T3) and group 4 (T4) significantly (P≤0.05) higher final body weight, average daily body weight gain and feed conversion ratio, then those from (T1) . Moreover , animals from T3 and T4 had significant (P≤0.05) higher production performance compared to those in T2 . The weights of hot , cold carcass, and the three main carcass cuts (leg, shoulder, and rack) were ignorantly (P≤0.05) heavier in T3 and T4 then other groups .The lambs in T3 andT4were also showed (P≤0.05) larger eye muscle area then T1 and T2. There were no significant differences in dressing-out %,or fat thickness between the treatment groups .
