Effects of Dietary Garlic (allium Sativum) Meal on Skin Thickness and Fat Deposition in Commercial Broiler Chickens

Excessive deposition of fat in the skin of commercial chickens has major implications on human health. Garlic (Allium sativum) has been reported to have hypolipidaemic effect in animals. The effect of garlic on fat deposition in the skin of commercial broilers was therefore investigated. One hundred and sixty day-old Arbor acres broilers of different sexes were randomly separated into four groups. Group A was fed a plain ration; group B had 0.125% garlic meal (GM) in feed continuously, group C – 0.125% GM at pulse inclusion (on for 2 weeks and off for 2 weeks) and group D – 0.25% GM continuously. At 4 and 8 weeks of age, five broilers per group were randomly selected, euthanised and back cape skin sections were harvested and processed for histology. Epidermal as well as dermalhypodermal thicknesses were measured. Data were statistically analysed using Duncan’s multiple range test and Student’s t-test at P<0.05. The epidermis in the control group (Group A) was significantly different vs the other groups at 8 weeks of age. Dermal-hypodermal thickness of group C (15296.1±965.7 μm) was significantly higher vs other groups at 4 weeks of age. Fat globules were relatively more abundant in the hypodermis of group A at 4 and 8 weeks of age, while collagen fibres in the dermis were relatively denser in the GM-supplemented groups. It was concluded that garlic inclusion in feed of commercial broilers resulted in thinner epidermis and denser collagen fibres in the dermis causing thicker dermis-hypodermis, as well as decreased fat deposits in the hypodermis.