Effect of dietary supplementation of antibiotic growth promoters vs synbiotics on growth performance, carcass characteristics and immune response of broiler chickens

A study was to conducted to evaluate the effects of dietary supplementation of antibiotic growth promoters (AGPs) – (Oxytetracycline OTC and Chlortetracycline CTC) and synbiotics on growth performance, carcass characteristics and immune response of broiler chickens. A total of 240 day-old broiler chicks were randomly assigned to six dietary treatments each consisting of eight replicates and each replicate having 5 birds and reared up to 42 days of age. The dietary treatments were (T1) control group with basal diet, (T2) basal diet supplemented with oxytetracycline-OTC (at 100mg/kg), (T3) basal diet supplemented oxytetracycline-OTC (at 200 mg/kg) (T4) basal diet supplemented with chlortetracycline-CTC (at 100 mg/kg), (T5) basal diet supplemented chlortetracycline-CTC (at 200 mg/kg) and (T6) basal diet supplemented with synbiotics(at 250 mg/kg). The birds were provided with ad-libitum feed and drinking water during the entire experimental period. Weekly feed intake, body weight gain, feed conversion ratio, carcass traits and immune response were recorded. The body weight gain of broilers were significantly (P<0.05) higher in the dietary groups on supplementation of OTC, CTC or synbiotics. Supplementation of AGPs or synbiotics did not have any significant (P>0.05) influence on cumulative feed consumption and feed conversion ratio of broilers during pre-starter and finisher phases and during overall period (0-42 d).There was no significant (P>0.05) influence of AGPs or synbiotics on any of the carcass parameters studied in the present investigation. There was no significant (P>0.05) difference in CBH response and log2ND titre valuesamong the treated groups but numerically higher CBH response was noticed in all treatment groups compared to control.The control and synbiotic groups had higher log2 titre than different antibiotic fed groups but present study revealed that synbiotics can also be used as alternative to antibiotic growth promoters in broiler production.