Etude de l'efficacité protéique de quelques régimes experimentaux chez le jeune alevin de loup Dicentrarchus labrax par la méthode des bilans azotés et énergétiques

Abstract

Study of protein efficiency of some experimental diets on sea bass (Dicentrarchus labrax) fry with protein and energy digestibility method. Sea bass fry adapted to nine isonitrogenous, isolipidics and isoenergetics diets were used to study protein and energy digestibilities in relation to dietary protein sources. The reference diet was based on fish meal, whereas the other diets contained greaves meal, fish protein hydrolysate, squid meal and soya protein hydrolysate at 30 or 50% of crude protein at the expense of fish meal protein. Protein and energy apparent digestibility was high and varied between 86 and 91% for proteins and between 89 and 92% for the energy. By it self, digestibility method had not clearly reflected the nutritive values of dietary proteins and could not be considered as a good criteria to evaluate the biologic value of dietary proteins, at least when digestibilities of protein sources are nearly similar. But, studies on digestibilities remain very useful to preselect feed stuffs from a large variety of raw materials available on the market.