It has been shown that addition of fennel in the diets of domestic animals has positive and beneficial effects on growth and meat production traits. Thus, the purpose of current study was to investigate the effect of adding fennel in the ration on growth characteristics and on insulin-like growth factor 1 (IGF1) gene expression in muscle tissue of Kermani lamb. Feeding of animals were performed with three levels of fennel including zero, 10 and 20 g/kg dry matter (DM) for 90 days. After slaughter, small pieces of tissues were removed and rapidly transferred to a nitrogen tank. Then, total RNA extracting and the Real-Time PCR reaction was performed. Results showed that as the level of fennel in the diet increases the amount of IGF1 gene expression also increases significantly in humeral muscle and femur (leg) muscle tissues (p < 0.05). In animals fed with fennel, femur muscle weight, back muscle weight, lean meat weight, final weight, warm carcass weight and live daily gain were greater than in animals fed with diet without fennel (p < 0.05). According to the findings of this investigation, it can be concluded that fennel, by creating positive effects on IGF1 gene expression can be used to improve muscle structure.
Keywords: Growth characteristics; Real-Time PCR; diet; femur; humeral.