Effects of somatic growth and insulin-like growth factor mRNA expression in the liver of salmon by feeding with sugarcane bagasse extract

Abstract

We examined the ability of sugarcane bagasse extract (SBE) to accelerate the somatic growth and insulin-like growth factor-I (IGF-I) mRNA expression of rainbow trout Oncorhynchus mykiss and coho salmon Oncorhynchus kisutsh. Those fed pellets containing 100 mg and 500 mg/kg SBE showed significant increases in body weight compared with the control. Higher IGF-I mRNA levels in the liver at the end of sampling time was observed in fish fed pellets containing 100 mg and 500 mg/kg of SBE. No change in body weight and hepatic IGF-I mRNA expression was observed following a feeding pellet with 1,000 mg/kg SBE. Incubation of the liver pieces with DDW-extracted SBE at concentrations of 100 and 200 µl/ml for 24 hr at 15°C resulted in a concentration-dependent increases in IGF-I mRNA expression. These results suggest that SBE might be enhanced IGF-I mRNA expression in the liver, and subsequently improved somatic growth of rainbow trout and coho salmon.