Effect of Bacillus subtilis as a Probiotic on the Productive and Physiological Performance of Broilers

Broiler chickens are reared in relatively dense colonies or flocks under intensive production environments to reach opportunities for financial efficiency. A plethora of variables, including overcrowding, immunization, and transportation, can cause serious stress. This study aimed to determine changes in the productive and physiological performance of broiler chickens (Rose ۳۰۸) after adding different concentrations of the probiotic liquid Bacillus subtitles (B. subtitles)  to their diet. A total of ۱۲۰ birds of the hatching age (Ross ۳۰۸) were divided into four groups, each of which had three replicates. Each repetition included ۱۰ birds the experiment lasted for five weeks after it commenced. The implementation of the diets was as follows: the control group received a regular diet without probiotic, and the probiotic-treated groups were supplemented with different concentrations of B. subtilis BSW equal to ۱×۱۰۴, ۱×۱۰۶, and ۱×۱۰۸ CFU/gm diet. At the end of the trial, the results indicated a significant improvement in both the live body weight and the efficiency of feed conversion when adding different levels of probiotics to the broilers diet. Furthermore, the findings showed a significant increase (P≤۰.۰۵) in the total serum protein, serum albumin, and serum globulin for the treated groups, compared to the control group at the age of five weeks. It is concluded that the dietary supplementation of B. subtilis BSW to the diet of broilers significantly improved their growth performance, in comparison with the control group. Instead, the treated groups exhibited a substantial increase in the total serum protein, serum albumin, and serum globulin, as compared to the control group. These findings suggest that B. subtilis BSW strain possesses probiotic properties, making it a suitable supplement for the poultry diet.