الفهرس 
1. Acacia saligna usageOnly 14 pages are availabe for public view
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Abstract
This study was conducted to evaluate the effect of feeding graded levels of Acacia saligna leaves hay (ALH) on the performance of sheep performance. The experimental work was divided into two experiments. The first experiment was conducted on Barki ewes during late pregnancy and lactating season. Forty ewes (ten ewes per group) aged 3-5 years old at the last third of pregnancy and weighed 38.0±1.2 kg were fed with 0, 20, 40 and 60% of ALH as berseem hay replacement in a completely randomize design for 250 days. The results showed non-significant differences in daily DM intake and digestibility coefficients for DM, EE, NFE and cellulose. Diets of 40% and 60% ALH showed higher (P<0.05) OM, CF, NDF digestibility comparing to 20% ALH and control diets. The highest (P<0.05) NB was recorded for ewes fed 60% followed by 40% ALH. The incorporation of ALH at levels 20, 40 and 60% resulted in non-significant differences in live body weight at all periods of the late pregnancy. Pregnant ewes fed 60% ALH diet recorded the highest (P<0.05) body weight gain (Kg), daily gain (g/day) and milk yield. Birth weights of lambs were not significantly affected. Blood urea decreased (P<0.05) with the graded percentage of ALH inclusion instead of Berseem hay. The results of this study revealed that inclusion of ALH up to 60% instead of dietary berseem hay could be best for improving nutrient utilization and performance of Barki ewes during late pregnancy stage. The Second experiment of this study was conducted to study the effect of feeding diets containing 40 and 60% ALH instead of berseem hay on growth performance, digestibility, nitrogen utilization, rumen function and economical feed efficiency and carcass characteristics. Twenty four Barki lambs with an initial body weight of 22.0±0.64 kg and aged 6±0.5 months were used, and divided randomly into three groups, eight lambs each. The experiment lasted 20 weeks. Inclusion of ALH in lambs diets significantly (p<0.05) improved the (P<0.05) OM, CP and CF digestibility coefficients and did not significantly (P>0.05) affect the digestibility of DM, EE and NFE, increased (P<0.01) N retention, overall mean of rumen NH3-N concentrations, insignificantly (p>0.05) increased the rumen VFAs concentration, significantly (P<0.05) decreased Ophryoscolex, Polystron and Holotrich (Dasytrich and Isotrich) species count, did not affect MP production at 3, 6 and 9 hrs after feeding, improved (P<0.05) daily and final body weight gain, feed conversion, dressing percentage, but it did not affect weights of the best ribs (9th, 10th and 11th rib) and its components of meat, subcutaneous fat, and fat between muscles, total fat, and bone, increased DM and CP content of lambs meat. The present results of this study could be concluded that ALH could be successfully and safely to replace 40 and 60% of berseem hay in the diets of pregnant Barki ewes and growing lambs. This may be due to Acacia saligna hay content of condensed tannins could be maximize the utilization of dietary protein and animal performance. Hence, using Acacia as feed for livestock is considered to be partially and cheaper solution to the problem of feed shortage in arid and semi-arid areas.