Optimum inclusion level of marine protein hydrolysates as supplements and major ingredients in fish diets

Abstract

A 67-day feeding trial was conducted with juvenile tilapia (Oreochromis niloticus) (approx. 5 g). Seven experimental diets were formulated in which a control diet was included containing fishmeal as the major protein source. A second type practical diet served as the basis of 5 treatments, in which partial substitution of fishmeal was achieved by varying levels of Sopro peche (C.P.S.P. Special G) and hydrolysed prawn wastes. The C.P.S.P. Special G is made from whole fish or fish offal from filleting industries; it is a kind of protein hydrolysates. The prawn wastes were prepared by lactic-acid fermentation of discards from the processing of prawns, Penaeus monodon, from Thailand. In terms of growth performance and feed utilization, it was found that an optimum ratio of Sopro peche could effectively replace up to 40% of the fishmeal in practical diets for tilapia. Diets containing prawn wastes, which replaced 33% fishmeal, displayed a significant reduction in growth performance and feed utilization