抄録
The preliminary feeding experiment on growth of carp fingerlings with fat-free, methyl linoleate and linolenate diets was conducted to determine the carp requirement for essential fatty acids (EFA) as compared with that of rainbow trout. Neither mortality nor abnormality was recognized in experimental fish throughout the feeding trial period, differing con-siderably from the case for rainbow trout which showed a “shock syndrome” on the fat-free diet. Feeding on a fat free diet resulted in the lowest growth, however judging from the percent gain and feed conversion, growth was not as poor as in the case of the rainbow trout. The addition of 5% methyl laurate to the fat-free diet noticeably improved the weight gain. These results indicate that the lowest growth rate obtained in the fat-free group may be partly a result of the lower caloric content due to the absence of fat. In other experimental groups, there was no significant difference in growth and feed conversion due to dietary lipids. The results obtained in this study demonstrate that the EFA requirement of carp is much lower than that of rainbow trout and that carp can grow without abnormality for a fairly long period without EFA.
