Effects of Feeding Strategies on Growth, Intestine Digestive Enzymes Activities and Intestine Morphology of Megalobrama pellegrini

In our report, in order to analyze the effects of feeding rate and feeding frequency on growth performance, digestive enzymes activities and intestine development of Megalobrama pellegrini in replicated flow-through system, a 42-day experiment was performed, in which three feeding rate（5%, 6.5% and 8% body weight/day, BW/d） and two feeding frequency（2 and 3 meals/day, m/d）, with a commercial diet（33% crude protein, 4% total lipid）, were designed. The results showed that the highest weight gain was found in fish with 6.5% BW/day and 3 m/d, which was significant higher compared with that of other feeding rate groups（5% BW/d and 8% BW/d） at both feeding frequency（2 and 3 m/d）, and which suggested that fish growth performance was significantly affected by the feeding rate but not by the feeding frequency. The significant higher feed conversion ratio（FCR） was recorded at 8% BW/d with 3 m/d compared with other treatments. When fish fed diet was at 8% BW/d with 2 m/d, the mortality was higher that of other groups. When fish fed diet was at 8% BW/d with 3 m/d, the whole-body crude protein, lipid and intestine digestive enzymes were significant lower than that of other groups, with intestine villi fusion and exfoliation observed. In conclusion, M. pellegrini fed diet with feeding rate of 6.5% BW/d and feeding frequency of 2 m/d could be the optimum feeding strategies raised in flow-through system.