Dietary inclusion of detoxified Jatropha curcas kernel meal: effects on growth performance and metabolic efficiency in common carp, Cyprinus carpio L.

Jatropha curcas is a multipurpose and drought-resistant shrub or small tree widespread all over the tropics and subtropics Its seeds are rich in oil, and the Jatropha kernel meal obtained after oil extraction is rich in protein However, presence of toxic and antinutritional constituents restricts its use in fish feed Jatropha kernel meal was detoxified Common carp, Cyprinus carpio, fingerlings (15, av body mass 109 +/- 0 65 g) were randomly distributed in three groups with five replicates A 6-week feeding experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilisation and energy budget Fish were fed isonitrogenous diets (38% crude protein) control diet (C-ontrol group) containing fish meal (FM) protein based protein and two other diets replacing 75% FM protein with detoxified Jatropha kernel meal (DJKM, J(atropha) group) and soybean meal (SBM, S-oybean group) At the end of the experiment, body mass gain, metabolic growth rate, protein efficiency ratio, protein productive value, energy retention, efficiency of metabolised energy for growth and efficiency of energy retention were determined These parameters were high and statistically similar for C-ontrol and J(atropha) groups and significantly lower (P <0 05) for S-oybean group Whereas a reverse trend was observed for energy expenditure per g protein retained in fish body No significant differences were found in heat released, gross energy uptake, metabolised energy intake, metabolisability, energy expenditure, energy expenditure per g protein fed and apparently unmetabolised energy Conclusively, common carp fed plant protein (DJKM and SBM) and FM protein based diets exhibited equal average metabolic rate