Hepatopancreas and gonad quality of chinese mitten crabs fattened with natural and formulated diets

Abstract

After 42 days of feeding on either a Huayi formulated diet (HY) or trash fish (TF), the hepatopancreas and gonad quality of the Chinese mitten crab, Eriocheir sinensis were compared. The hepatosomatic index (HSI), gonadosomatic index (GSI) and proximate composition of both genders were similar. There were no significant differences in the total collagen content in the hepatopancreas between both dietary treatments, but collagen content was dramatically higher in the ovaries compared to the testes. Diets had no significant effect on the free amino acid content (FAA) of the hepatopancreas and gonads, but gender significantly affected the contents of certain amino acids. Compared to females, the hepatopancreas and gonads of males had significantly higher docosahexaenoic acid (DHA), long-chain polyunsaturated fatty acids (ΣLcPUFA), omega-3 polyunsaturated fatty acids (Σn-3PUFA) content as well as DHA/eicosapentaenoic acid (EPA), n-3/n-6-values. Practical Applications: Trash fish (TF), which are considered as standard food for fattening Eriocheir sinensis in China, have many disadvantages: they vary greatly in nutritional quality, decay rapidly and are not convenient to store over long periods. Thus, alternate supplies of cost-efficient, easily-modified and practical diets are highly preferred. To our knowledge, no study exists that has used formulated diets to find their effects on the product quality of the hepatopancreas and gonads on a commercial scale. The current study showed that the formulated diet could completely replace TF in fattening mitten crab without affecting hepatopancreas or gonad quality, and could provide an answer to the controversy over the use of formulated diets or TF for crab farmers. Various indices in this study also suggested that the hepatopancreas and gonads could be beneficial for human health and would be suitable for processing into different crab products. © 2013 Wiley Periodicals, Inc.