A comparative evaluation of fermented and unfermented soybean and guar meal on growth performance, nutrient retention, caecal microflora, and excreta gas emission of broiler chickens

Abstract

Abstract This experiment was conducted to evaluate the possibility of a 10% replacement of soy bean meal (SBM) with guar meal (GM) in broiler diets and the effects of fermentation of SBM and GM with Bacillus subtilis. A total of 384 Ross 308 (1-d old) broilers were selected for 4 treatments, with 6 replications, and 16 broilers per replication for 35 d. Experimental treatments consisted of a 2 × 2 factorial design with the following factors: i) two protein sources (SBM or GM), and ii) 10% of the SBM resp. GM fermented with B. subtilis. The results showed that broilers fed SBM or fermented diets showed improved body weight gain and feed conversion ratio compared to those fed GM ( P<Â 0.05). The nutrient retention of dry matter, nitrogen, and energy of broilers fed SBM or fermented diets were higher than those fed GM ( P<Â 0.05). The caecal microflora counts were improved (increased Lactobacillus and decreased coliforms) with the addition of fermented diets ( P<Â 0.05). Ammonia gas emission in the fermented treatments was lower than that in the unfermented treatments ( P<Â 0.05). Together, these findings suggest that adding SBM and GM fermented with Bacillus subtilis in the diet can improve growth performance and nutrient retention and decrease excreta noxious gas emission. Finally, GM fermented with Bacillus subtilis could replace SBM by 10% with no adverse effect on broiler performance.