Effect of Somatotropin on Growth Performance and Protein Metabolism of Fish, Labeorohita (Hamilton,1822)

Abstract

Growth hormone (GH) has multiple targets and diverse effects in vertebrates. It is a principal promoter of growth, and also influences the metabolism. This paper reports the effect of exogenous Somatotropin(Growth Hormone-GH) on growth promoting efficiency, total proteins, RNA and DNA levels in fish,Labeorohita. The present study was conducted to assess an anabolic impactof Somatotropin (Growth Hormone-GH) on protein content and RNA levels in certain tissues i.e. skeletal muscle and liver of fish, Labeorohita. The hormone was incorporated in the diet and fed to the three groups of fish upto 40 days, in the form of three pelleted diets containing 2, 4, 6 mg GH/ kg diet along with a fourth control group fed diet without hormone. From the results obtained, it was clear that the hormone GH has promoted the growth of fish over the control. Growth performance was monitored by recording the bodyweight gain(g) and liver weight. SGR values increased with the increase of hormone dose.The present study revealed that the GH induced growth enhancement of Labeorohita.The highest increment in tissue Protein content, RNA and DNA content was observed under 6 mg GH/ kg diet followed by 4 mg GH/ kg diet and 2 mg GH/ kg diet in skeletal muscle and liver of fish. Hence, it was clear that the anabolic hormones such as GH play an important role in enhancing the tissue protein content for nutritional purpose of man. There was not much change in DNA levels.