The effect of Bacillus subtilis GM2 and GM5 probiotics on the growth and fodder digestibility of broiler chickens

Abstract

The probiotic properties of the Bacillus subtilis GM2 and GM5 strains were studied on 90 Cobb 500 broiler chickens aged one day that were randomly divided into three groups: the control group with the standard diet and two experimental groups (30 chickens per group) with the diet supplemented with B. subtilis GM2 (group 1) and GM5 (group 2) spores. The addition of B. subtilis GM2 and GM5 spores at a concentration of 1·107 CFU/g to the ration of broiler chickens improved their growth rate, as well as increased the digestibility of nutrients and modulated the intestinal microflora in them. The use of probiotics stimulated an increase in the live weight of chickens by 6.30% and 13.78% (p = 0.05) as compared with the control group. The average daily weight gain in experimental groups 1 and 2 amounted to 52.82 ± 0.36 g and 56.54 ± 0.47 g per chicken, which is more than in the control group (49.69 ± 0.40 g) – by 6.30% and 13.79% (p = 0.05), respectively. The administration of probiotics by feeding favored an increase in the population of lactic acid bacteria in the small and large (to a lesser extent) intestine – bacteria belonging to the Enterobacteriaceae, Lactobacillaceae, and Clostridiaceae families were isolated from the intestinal contents and identified. The veterinary-sanitary examination found that the meat of broiler chickens from the experimental groups meets all the GOST requirements for organoleptic, physico-chemical, and bacterioscopic characteristics. Thus, probiotics based on the B. subtilis GM2 and GM5 strains have a positive effect on the growth and fodder digestibility of broiler chickens.

Keywords

• probiotics
• bacillus subtilis gm2
• bacillus subtilis gm5
• broiler chickens
• productivity
• intestinal microbiota