Resumen:
The current research was conducted to evaluate the influence of newly developed probiotic (Microzist) and commercial probiotic (Primalac) on growth performance, carcass characteristics, and immunity of broiler chickens. A total of 225 one-day-old broiler chicks Ross-308 was randomly assigned into 5 groups – control group, group with 0.2, 0.25, and 0.3 g/kg of Microzist, and group constituting Primalac (starter: 0.9 g/kg, grower: 0.454 g/kg, and finisher: 0.225 g/kg). At 42nd day of age, there were no statistically significant differences among treatments on daily weight gain and feed conversion ratio (P > .05), but treatment’s effect on the feed intake was found to be significant (P < .05). Diet supplementation with various concentrations of Microzist showed growth performance of broiler chickens more or less similar to the Primalac additives. There were statistically significant differences (P < .05) among treatments on the carcass characteristics. Microzist (0.2 g/kg) reduced the abdominal fat content in broiler chickens in a comparison with control as well as Primalac (P < .05). Furthermore, Microzist showed no influence on the immunological organ weights. The present investigation indicates that Microzist may be a potential alternative to antibiotic growth promoters as well as widely used Primalac in broiler industries.