Avaliação de dois métodos de determinação do coeficiente de digestibilidade aparente com a tilápia do Nilo ( Oreochromis niloticus L.)

Abstract

The objective of this study was, in the first experiment, to evaluate the apparent digestibility of dry matter (DM), crude protein (CP) and ether extract (EE) of purified diet using chromic oxide as inert marker, in the three parts of intestine (proximal, middle and distal) of Nile tilapia, Oreochromis niloticus L (Perciformes Cichlidae). In the second experiment, the aim was to compare the digestibility coefficients obtained by natural excretion in the digestibility aquarium and by intestine dissection. The results showed that in the distal portion there was an increase in the absorption, the dissection method underestimates the digestibility of collected material (DM=41.79%a, CP=48.98a, EE=35.10%b) and that the digestibility coefficients obtained by indirect method with feces collected in the digestibility aquariums are more reliable and real (DM=63.99%b, CP=85.62b, EE=73.60%b).