Effects of Garlic Feed Inclusion on Experimental Salmonella gallinarum Infection in Broiler Chickens (Gallus gallus domesticus)

Abstract

Garlic is a spice and herbal medicine with antibacterial, antioxidant and immunomodulatory effects. In view of global demand for reduction in antibiotic use in poultry production, the potential of garlic at controlling fowl typhoid was investigated. Day-old (75) broiler chicks were separated into groups A, B, C, D and E of fifteen each, placed in cages for brooding and administered 0.125%, 0.25%, 0.5%, 0% and 0.125% garlic-meal, respectively, in feed. At 9 week-old, each chick in groups A, B, C and D were inoculated with 8x10⁶ cfu/ml PBS of Salmonella gallinarum, orally, while those in Group E were given PBS only. Up till 10 days post-infection (pi), clinical signs were scored from 1-3 based on degree of severity i.e. 1(mild), 2 (moderate) and 3 (severe). Mortality and gross pathology per group were recorded. Samples from liver and gall bladder were harvested for bacterial re-isolation. Groups A, B and C showed mild diarrhoea while group D showed in addition, anorexia, ruffled feathers and unthriftiness. Diarrhoea in groups A and B spanned days 2 -7 pi, group C on day 3 pi while in group D, days 1-10 pi with increasing degree of severity. Total diarrhoea scores were 6(A), 4(B), 1(C), 23(D) and 0(E) while mortalities were 2(A), 0(B), 2(C), 4(D) and 0(E). Enlarged and congested/bronze-coloured liver, engorged gall bladder and catarrhal enteritis were observed in carcasses. Colonial and cellular morphology of re-isolated bacteria were typical of S. Gallinarum. Garlic-meal ameliorated the effects of S. Gallinarum infection with the best result at 0.25%.

Keywords: broiler chickens; antibacterial; fowl typhoid; Garlic; Salmonella gallinarum