Authors:

Abstract

Purpose : Apparent digestibility coefficients of nutrients in Jatropha curcas based diets were evaluated for Nile tilapia (Oreochromis niloticus) using AIA as marker or indicator.

Research Method : A total of 225tilapia were acclimatized for a week, weighed and allotted into five dietary treatments; containing 20 and 40% of 5- and 10-minute toasted Jatropha curcas replacing soybean meal in control diets. The diets were isonitrogenous and isolipidic. Each treatment was replicated three times with fifteen fish per replicate. Fish were fed 5% body weight on two equal proportions per day. Acid insoluble ash and digestibility coefficient determinations followed standard established procedures.

Findings : The results from the study indicated that the apparent digestibility coefficients of nutrients in control diets were significantly (p<0.05) higher than that test diets containing Jatropha curcas seedmeal. There was a reduction in the apparent digestibility coefficients of nutrients in the diet with increase replacement levels which were significant (p<0.05) at a 10-minute processing time. However, no significant difference (p>0.05) was observed in the apparent digestibility coefficient of nutrients in 5-minute toasted Jatropha up to 40% soybean replacement among the fish fed the diet. So also, the apparent carbohydrate digestibility coefficient of the different test dietary treatments was not statistically different (p>0.05).

Originality / Value : It is evident from this study that diets containing Jatropha curcas seedmeal were relatively well digested by Oreochromis niloticus compared with soybean-based diets.

Keywords: Jatropha, apparent protein digestibility, tilapia, acid insoluble ash, apparent lipid digestibility