Abstract

A study was conducted to assess the effect of dietary garlic (Allium sativum) supplementation on the performance and meat quality of broiler chickens using a total of 300 day old Shaver Starbo chicks allotted at 10 birds per replicate and 6 replicates per treatment over a period of 7 weeks. The basal starter and finisher diets contained 228.61 and 201.42 g/kg CP, respectively. The control diet was the basal diet without garlic supplementation. Diets 2 and 3 contained supplementary raw garlic powder at 500 and 5,000 mg/kg diet respectively, while diets 4 and 5 contained supplementary boiled garlic powder at 500 and 5,000 mg/kg diet respectively. 4 female birds per replicate were slaughtered at the end of the trial to evaluate carcass and muscle characteristics, garlic aroma and palatability scores of the meat and oxidative stability of refrigerated meat at 4°C for 6 days were determined. The average weight gain, average feed intake and feed conversion ratio of the birds were not significantly (P > 0.05) influenced by dietary treatments. Broiler chickens fed garlic supplemented diets had marginally higher weight gain than those fed the control diet and was higher at high level of garlic supplementation (39.18 ± 0.94, 40.42 ± 0.45, 42.39 ± 1.57, 39.72 ± 2.97 and 41.42± 2.60 g/bird/day for Diets 1, 2, 3, 4 and 5 respectively; P > 0.05).  The carcass and organ characteristics of the chickens were not significantly affected (P>0.05) by dietary garlic supplementation but abdominal fat contents were numerically lowered due to supplementary garlic. Moisture contents of broiler chickens were not significantly (P > 0.05) influenced. Garlic aroma (P < 0.001) and palatability (P > 0.05) scores increased with increasing level of dietary garlic supplementation. Thigh muscle had the highest score for garlic aroma (2.60 ± 1.30), followed by drumstick (2.57 ± 1.14) and lowest for breast muscle (2.50 ± 1.17) (P > 0.05). Oxidation susceptibility of meat, measured as concentration of malondialdehyde (MDA), decreased with increasing level of supplementary garlic fed to the chickens (P < 0.01). Muscle MDA concentration was in order of thigh > drumstick > breast (P < 0.001). It was concluded that supplementation of chicken diets with garlic marginally improved weight gain and it was better at high level of supplementation (5,000 mg/kg diet). Boiled compared with raw garlic powder produced no beneficial effect. Dietary garlic supplementation improved meat quality by increasing meat palatability score and reducing the extent of oxidation of meat during refrigerated storage.

Key words: Broilers, performance, meat, garlic aroma, palatability, oxidative stability, garlic.