EFFECTS OF AN HYPOPROTEIC SOYBEAN BASED DIET ON THE ENERGY STORES ANDGROWTH OF CARP (CYPRINUS-CARPIO L.)

The possibility of using an hypoproteic soybean based diet for a long period was tested on young carps, Cyprinus carpio. The growth and the energy content in the liver, muscle and plasma were investigated both in laboratory conditions after 1 year of experimental feeding, and in natural conditions after 7 months. The efficiency of the soybean based diet was compared to a standard diet containing animal proteins. Afte r 1 year in the laboratory, the growth with the soybean based diet (SB D) was low (128%), but the natural conditions greatly improved the gro wth (1190% after 7 months). The hepatic and muscular lipid contents in the laboratory condition decreased in the SBD fed carps while the gly cogen store in muscle increased. In the natural condition, the lipid c ontent only decreased in the muscle. These alterations suggest that li pids were used preferentially as the source of energy. In natural cond itions, allowing a natural complementation, the SBD efficiency was imp roved. The SBD can therefore be envisaged in carp semi-intensive cultu re. (C) 1998 Elsevier Science Inc. All lights reserved.