THE GROWTH PERFORMANCES AND THE FATTY ACID COMPOSITIONS OF DOJO LOACH MISGURNUS ANGUILLICAUDATUS FRY FED WITH DIFFERENT LIPID SOURCES

In this study, we conducted a 40-day feeding trial to evaluate the effects of different dietary lipids on the growth performance and the fatty acid composition of loach Misgurnus anguillicaudatus fry. Fish with average initial weight of (10.002.00) mg were fed with five experimental diets that contained fish oil (FO), soybean oil (SO), corn oil (CO), peanut oil (PeO) or palm oil (PaO). There were no significant differences in the weight gain, the specific growth rate, the feed conversion ratio, the survival rate, and the whole body proximate between different feeding groups. However, the concentration of the polar lipid in fish fed with FO diet was significantly higher than those fed with other plant oil diets. The portions of total n-3 fatty acids and EPA+DHA in the neutral and polar lipids of fish fed with FO diet were significantly higher than other groups fed with plant oil diets. We observed a significantly higher level of arachidonic acid (ARA, 20:4n-6) in the polar lipid in the SO, CO, PeO and PaO groups compared to the FO group, which indicated that the loach were highly capable of transforming linoleate into arachidonate. Therefore we concluded that in the presence of sufficient dietary phospholipids, FO, SO, CO, PeO and PaO could be used in the diet for the loach during their early developmental stages.