Investigation on the effects of dietary protease supplementation in broiler diets ‎containing full-fat soybean extruded at different temperatures

For this expriment 1440 Ross 308 male broilers (from 1 to 42 days of age) were used in a randomized complete block design with eight treatments in six blocks. Experimental diets included: soybean meal (control treatment), raw soybeans, full-fat soybeans extruded (15%) at 90 and 150°C, and each of them with 0.02% or without (0.0) protease enzyme supplementation. The use of raw soybean compared to soybean meal or extruded full-fat soybean significantly reduced feed intake, body weight and relative carcass weight, as well as increased feed conversion ratio and pancreatic weight (P<0.01). weight gain was improved in diets supplemented by protease enzyme compared to diets containing raw soybean (P<0.01). Feed conversion ratio was improved in diets containing raw soybean and soy bean meal by dietary protease supplementation (P<0.01). Extrusion temperature did not affect the growth performance of experimental birds. Diet containing raw soybean without enzyme increased blood cholesterol levels (P <0.05). According to the findings of this study, the use of protease enzyme in diets containing soybean meal or raw soybean can improve the performance of broilers However, such effect is less pronounced in diets containing extruded full-fat soybean meal.