Dietary administration of testosterone propionate on growth, proximate composition and residual content of pearlspot, <i>Etroplus suratensis</i> (Bloch) (Cichledae)

Abstract

Juveniles of pearlspot were fed a synthetic hormone testosterone propionate (TP) at levels 1, 2, 3, 4 and 5 ppm incorporated in a prepared supplementary diet having 40% protein for 120 days. Fishes fed diet containing 4 ppm testosterone propionate showed significantly (p<0.01) superior growth than control and other levels of TP. Improvement in feed utilisation in terms of better feed consumption, higher feed conversion efficiency, enhanced nutrient digestibility and increased digestive enzymes activity was observed in the fishes fed 4 ppm TP. High RNA, DNA contents and RNA/DNA ratio in the muscle and liver were noticed in the TP treated fishes. The muscle protein content of TP fed fishes was significantly (p<0.01) increased from that of the control. Residual hormone content found in the treated fishes on termination of the experiment (120 days) has been dropped to the normal level as that of the control on the 30th day after stop feeding hormone diet. Testosterone propionate at 4 ppm level can be suggested as the optimum dosage required to bring about an additional growth increment. (111.02%) without any residual hormonal effect.