Effect of replacement Soybean meal with crud, extruded and roasted full-fat soybean on fattening performance, rumen parameters, apparent digestibility and feeding behaviors in Afshari male lambs

Oil seeds are commonly used in the diet of Ruminant nutrition to meet energy and protein requirements. To eliminate the anti-nutritional substances and increasing bypass protein, soybean seeds are processed, and heat is the most common way used to processing soybeans. So using bypass proteins is important, Soybean processing causes rumen un-degradable protein content to be increased, that could increase protein absorption in the small intestine and improve nitrogen utilization efficiency. The main objectives of this research were the estimate the effect of dietary replacement of crud, extruded and rousted full-fat soybean with soybean meal on dry matter intake, growth performance, rumen parameters, diet digestibility and feeding behaviors in Afshari male lambs. Experimental diets were assigned to the 7 groups (n = 6/group) in a completely randomized design for a 74-d period (14 d for adaptation and 60 d for data collection). Experimental diets with equal ME and CP concentrations and a forage to-concentrate ratio of 30 to 70 were formulated: Treatment 1: contains 15 percent of soybean meal, treatment 2: Replace of 7.5 percent soybean meal with crud full fat soybean, Treatment 3: Replace of all soybean meal with crud full fat soybean, treatment 4: Replace of 7.5 percent of soybean meal with extruded full fat soybean, Treatment 5: Replace of all soybean meal with extruded full fat soybean, Treatment 6: Replace of 7.5 percent soybean meal with roasted full fat soybean, Treatment 7: Replace of all soybean meal with roasted full fat soybean. Dry matter intakes was effected by experimental diets (P <0.01). Using 15% rousted full fat soybean with the mean of 1.79 kg per day showed the highest dry matter intake. The use of extruded and rousted full fat soybean significantly increased daily gain in comparison with the crud full fat soybean and soybean meal (P <0.05). The use of extruded and rousted full fat soybean significantly reduced feed conversion ratio (P <0.01). In vivo digestibility of crud protein, dry matter and organic matter was not affected by the dietary treatment but neutral detergent fiber was affected by the dietary treatment (P <0.05). Feeding lambs on diets crud, extruded and rousted instead of soybean meal had no effect on volatile fatty acids and feeding behaviors. The use of extruded and roasted full-fat soybean with improved daily gain, in vivo digestibility and reduce feed conversion ratio, increased the fattening performance of Afshari male lamb.