Journal of Aquaculture Research & Development

Abstract

Evaluation of Acid-Insoluble Ash and Crude Fibre as Internal Markers in In Vivo Digestibility Studies: A Comparison in Three Cyprinid Species

Gangadhar Barlaya* and Perar Keshavanath

Though there are several reports of estimation of apparent nutrient digestibility values using different markers in fish nutritional studies, no study is available wherein the same nutrient digestibility was estimated using two or more markers. The study aimed at comparing the apparent Digestibility Coefficient (ADC) of nutrients, estimated using the markers-Acid-Insoluble Ash (AIA) and Crude Fibre (CF), in order to assess the suitability of digestibility markers. The apparent crude protein and fat digestibility values of experimental diets estimated in three indoor in vivo digestibility studies with cyprinids (Labeo fimbriatus, L. rohita and Hypselobabus pulchellus) using AIA and CF are compared. In these studies, graded dietary levels of cottonseed meal, azolla meal and moringa leaf meal, respectively were evaluated. Apparent digestibility coefficients for protein and fat were calculated from protein and fat in feed and fecal matter, using analyzed AIA and CF contents as digestibility markers. In all the cases, ADC of both crude protein and fat were higher when estimated using AIA as compared to those estimated using CF. However, the general trend in the pattern of variation of ADC values among the different treatments remained almost the same, irrespective of the marker used. The results indicate that AIA as an internal marker is the most appropriate on the basis of the degree of precision that could be achieved in quantification of digestibility. The findings of this study are expected to help fish nutritionists in selection of suitable markers for in vivo digestibility studies.

Published Date: 2023-12-11; Received Date: 2023-11-09