A total of 240 chicks (120 Nigerian heavy ecotype local chicken and 120 White Leghorn x local crossbred chicken) were used for this study, which was aimed at evaluating the performance and expression of interferon gamma (IFN-γ) gene in purebred and exotic-local crossbred chicks under the influence of garlic. The experimental design used was a 2x3 factorial (2 genotypes x 3 treatments: control, ciprofloxacin and garlic) in a completely randomized design. At 2 months and 4 months, 2gram of the tissues samples of the small intestinal was cut and immersed into RNA Later for expression of interferon gamma (IFN-γ) gene. cDNA were obtained using Solis Firescript cDNA synthesis kit according to manufacturer’s protocol. The interaction effect between the genotypes and treatment on body weight and body weight gains of F₁ offspring showed that highly (P<0.01) significant mean values of body weight were reported at day old, at 2 months and 4 months. Weight gains were significantly (P<0.01) different at 2 and 4 months of age. This shows that garlic helped in promoting growth features in the local x exotic crossbred genotype. At 2 months of age, the mRNA expression of interferon gamma (IFN-γ) gene in the small intestine for the crossbred genotype administered garlic were upregulated compared to the control group while the mRNA expressions of the ciprofloxacin group were down regulated compared to the control group. It was therefore revealed that the effect of garlic on the expression of interferon gamma (IFN-γ) gene was short-termed.

Index Terms - Crossbred, Garlic extract, Heavy ecotype, Interferon gamma gene, Purebred