Dietary Garlic Powder Supplementation Could Ameliorate Unfavorable Effects of Choline Deficiency on the Liver Health and Immune System of Broiler Chickens

Effects of different levels of choline and garlic powder on performance, liver health and immune response in broiler chickens were evaluated in this study. A factorial experiment with 2 dietary choline levels (the recommended level in Ross 308 broiler guidelines and 25 % less than the recommendation) and 3 dietary garlic powder levels (0, 5 or 10 g/kg diet) was conducted using Ross 308 broiler chickens. Four hundred eighty 1-d-old Ross 308 broiler chickens were randomly divided into 6 dietary treatments, each containing 4 replicate pens, with 20 birds each. During the finisher phase (d 25 to 42), dietary supplementation with 5 and 10 g/kg of garlic powder increased feed intake. At finisher phase and the whole experimental period, dietary supplementation with 10 g/kg of garlic powder improved the daily weight gain. During the finisher phase and the whole experimental period, the daily weight gain of birds fed low choline diets was less than that of birds fed recommended choline level. During the finisher phase and the whole experimental period, dietary choline deficiency increased feed conversion ratio. Choline deficiency decreased serum IgM level, and IgM concentration was higher in chicks fed diet with 5 g/kg garlic powder. However, dietary garlic powder at 10 g/kg level increased the total white blood cells and reduced the heterophyles numbers. Diets deficient in choline and also 10 g/kg dietary garlic powder increased the liver fat deposits. The liver Crea-tine phosphokinase (CPK) enzyme levels in the serum of chicks fed the choline-deficient diets were higher compared to birds fed the diets with recommended choline level. Consumption of garlic powder at 10 g/kg level, lowered serum CPK enzyme levels compared with the diets containing zero or 5 g/kg garlic powder. Choline deficiency and also dietary garlic regardless of its dosage were reduced the levels of serum triglyc-erides and very low density lipoproteins (VLDL). However, serum HDL were decreased in chickens fed 5 g/kg garlic powder compared with those fed garlic free diets. The findings of this study suggest that the effect of garlic powder in addressing the adverse effects caused by deficiency of choline are not through lipid metabolism improvement and more likely are due to the beneficial effects of garlic on increased feed intake , which increased choline intake and improved immune system function.