Effect of supplementation of marigold (Tagestes erecta) oleoresin on growth, survival and pigmentation of rosy barb, Puntius conchonius (Hamilton).

Abstract

The study was carried out for a period of 45 days to elucidate the effect of marigold oleoresin on growth, survivaland pigmentation of rosy barb, Puntius conchonius. Fish with initial weights ranging from 0.44 g to 0.47 g werefed with test diets T0, T1, T2 and T3 supplemented with marigold oleoresin at levels 0, 60, 120 and 180 ppmrespectively. At the end of the feeding trial the total carotenoid concentration in fish muscle found significantlyhigher (p < 0.05) in both male (3.92±0.01 μgg-1) and female (3.35±0.02 μgg-1) fishes fed diet incorporated with120 ppm marigold oleoresin. Survival rate of fish significantly increased (p < 0.05) with the supplementation ofmarigold oleoresin in the diet, highest being in 120 ppm level (96.66±3.33 %). However, there was nosignificant effect observed in growth, feed conversion ratio and specific growth rate of the fishes. Carotenoidcontent analysis from whole fish revealed that incorporation of dietary carotenoid resulted in a significantincrease in total carotenoid concentration. The study cluded that cheaper and natural colour enhancer dietsfor rosy barb can be prepared using marigold oleoresin at 120 ppm level