EFFECTS OF PROBIOTICS (Bacillus subtilis and Bacillus licheniformis) ON PERFORMANCE AND ANTIMICROBIAL ACTIVITY OF BROILER

Abstract

Antibiotics are used to fight against bacterial infection and bacterial resistance to antibiotic are increasing. Hence, this study was conducted to find out the efficacy of probiotics Bacillus subtilis (BS) and Bacillus licheniformis (BL) on performance and antimicrobial activity of broiler chicken. One-Day old of cobb-500 broiler chicks (n=150) were divided into 5 experimental groups with 3 replicates as 10 chicks in each replication. One of the 5 experimental group fed diet without probiotic was as control and the remaining four groups fed diet with 4 levels of commercial probiotics were T 1 (20g BS/metric ton feed), T 2 (50g BS/metric ton feed), T (20g BL/metric ton feed) and T 4 (50g BL/metric ton feed). The group T 4 3 treated with 50g BL/ metric ton feed (MT) showed higher body weight (1607.50±30.98g) compared to control (1472.14±38.51). Feed consumption was significantly (P<0.05) higher in control group than probiotic treated groups. FCR was better in all probiotic treated groups compared to the control (1.52±0.04) and the best feed conversion ratio (FCR) result was found in T group (1.33±0.02). Carcass percentage was significantly (P<0.05) higher in T 4 4 group (71.33±1.30) compared with the control (65.67±1.33). The weight of breast, thigh, drumstick and giblet was significantly (P<0.05) high in T group as compared to others treatment groups and control (T ). In addition, the present study showed that feeding dietary probiotics in different groups had no significant effect (P>0.05) on relative weight of neck, wing, intestine, gizzard, spleen and bursa. The numbers of intestinal microflora (E. coli and Salmonella) were significantly higher (P<0.05) in control group compared to other groups and among the treatment groups the number of salmonella bacteria was significantly lower (P<0.05) in T 0 group. Total expenditure per bird was significantly higher (P<0.05) in treated group (T ) than control group (T 0 ). Feed cost was significantly higher (P<0.05) in control group (T ) compared to different treated groups. BCR and profit per bird was significantly higher (P<0.05) in treatment groups than control (T 0 4 4 ) and among the treatment groups T

performed better than others. Overall, between these two probiotics (BS and BL), 50g BL/MT feed showed better results in terms of improved growth performance with better FCR, better carcass yield with net economic benefit. 2 0 4