Synbiotic supplements as antibiotic alternatives in broiler diets

Antibiotics can contribute to bacterial resistance, posing a significant public health concern. Synbiotics represent an effective alternative to antibiotics, promoting the balance of intestinal microbiota and creating a conducive environment for beneficial bacteria growth. This study aimed to assess the utility of the synbiotic supplement (+Poultry) as a substitute for antibiotics in broiler diets from 1 to 42 days of age. We evaluated its impact on performance during two stages: 1 to 21 days and 1 to 42 days, digestibility coefficients, metabolizable energy, duodenum and jejunum morphometry, carcass yield, and hematological parameters. A total of 440 Ross 308 strain broiler chicks, both males and females, were accommodated in 2m(2) cages from day 1 to day 42. The birds were randomly assigned to four treatments, with each treatment having five replications consisting of 22 birds, thus forming 20 experimental plots. The treatment groups were as follows: Basal diet (BD) without the addition of antibiotics or synbiotics, BD with 150ppm zinc bacitracin (BCZ), BD with 0.5kg/t of synbiotic, and BD with 1kg/t of synbiotic. The synbiotic supplement (+Poultry) used in this experiment, provided by Nutri+, contained amino acids, minerals, probiotic culture, prebiotic additives, and flavoring additives. Throughout the experiment, all birds were subjected to a weekly sanitary challenge, which involved using reused litter and water contaminated with litter. Treatment effects were observed on feed conversion (P = 0.0100) of broilers aged 1 to 21 days, indicating improved feed conversion in broilers consuming BD + 1kg/t synbiotic compared to BD alone. Consequently, we recommend the incorporation of a synbiotic supplement at a rate of 1kg/t as a viable antibiotic replacement for chickens aged 1 to 21 days. The tested synbiotic supplement shows promise as an antibiotic alternative in broiler diets at all life stages, maintaining both performance and bird health. Key words: Animal nutrition. Growth promoters. Poultry.