Effects of dietary supplementation with garlic powder (Allium sativum L.) on broiler performance, carcass traits, lymphoid organ development and intestinal biometrics

Aim of study: To assess the effects of dietary supplementation with garlic (Allium sativum L.) powder as a growth-promoting additive on the productive performance, carcass traits, intestinal biometrics, and lymphoid organ development of broilers. Area of study: Machado, Minas Gerais, southeast region of Brazil. Material and methods: A total of 660 one-day-old chicks were used in a completely randomized design with 5 treatments (0, 2.5, 5.0, 7.5, and 10.0 g/kg garlic powder), 6 replications, and 22 animals per experimental unit during 42 days of production, divided into phases: initial (1 to 7 days), growth (8 to 22 days), and finishing (23 to 42 days). Main results: In the total production period, the birds that were fed rations containing 5, 7.5 and 10 g/kg garlic powder showed increased weight gain and feed conversion ratio (p<0.05). Among the carcass yield variables, live weight and carcass yield showed a positive linear effect (p<0.05). Birds supplemented with garlic powder showed increased weight (p<0.05) and relative length of the small intestine (p<0.05). The absolute weight of the lymphoid organs, thymus and bursa of Fabricius, and the relative weight of the thymus, bursa of Fabricius and spleen also increased linearly with the level of dietary supplementation with garlic powder (p<0.05). Research highlights: Dietary supplementation with 5 g/kg and higher concentrations of garlic powder is recommended as a growth promoter for broilers because this feed additive enhances lymphoid organ development, improves intestinal biometric variables and consequently maximises the productive performance and carcass yield of broilers from 1 to 42 days of age.