FASTING IN HYBRID GROUPER EPINEPHELUS FUSCOGUTTATUS X EPINEPHELUS LANCEOLATUS IN RELATION TO PROXIMATE CONTENTS, GROWTH AND FEED EFFICIENCY

Abstract

Fasting in fish is commonly used to improve the quality of fish product post-slaughtered. This study aims to investigate the alteration in nutrient contents, growth, and feed efficiency of hybrid grouper Epinephelus fuscoguttatus x E. lanceolatus fasted at different intervals. There were two experiments conducted in this study. The first experiment evaluated alteration in nutrient contents of carcass and liver of hybrid groupers. The fishes were grouped into three feeding regimes: fed daily, fasted at a one-day interval, and fasted at a two-day interval. Each group had 50 fishes with an initial mean weight of 200 ± 11.3 g. The second experiment was to evaluate the growth and feed efficiency of the fishes. Hybrid groupers were subjected to two feeding regimes. The first group (n = 45) was fed daily, and the second group of fish (n = 45) fasted at a two-day interval. The first and second experiments were conducted for one and two months, respectively. The results show that hybrid groupers fed daily have the lowest protein and the highest fat in the carcass compared to those fasted on one- or two-day interval. During the first month, there was no difference between the growth rate of the fishes fed daily and fasted at a two-day interval (32.88 and 32.08%, respectively). However, in the second month, the fishes fed daily have a growth rate of 66.08%, which is 1.4 times higher than those fasted at a two-day interval (48.12%). Altogether, fasting in hybrid groupers could alter proximate contents, slow down growth, and improve feed efficiency.