Abstract:

A laboratory growth trial was conducted to evaluate the suitability of various oilseed cakes and
leucaena leaf meal as dietary protein sources for common carp fry (mean + SE weight, 50 k 1.6
mg). Eleven experimental diets were formulated containing different levels of mustard, sesame,
linseed, copra and groundnut oil cakes and leucaena leaf meal to substitute for fish meal protein
up to a maximum of 75% of the total protein content. Sesame oil cake was tested at three
inclusion levels (25, 50 and 75% of total protein), whereas mustard (25 and 50%), linseed (25 and
50%) and groundnut (25 and 75%) oil cakes were each tested at two levels. Copra and leucaena
were tested at one inclusion level (25% of total protein) only. The control diet was prepared with
fish meal as the sole source of protein. All diets were isonitrogenous and contained about 40%
protein. The experiment was conducted in a laboratory recirculation system with three replications
for each treatment. The performances of the diets were evaluated on the basis of feed acceptability,
survival, growth, feed conversion, protein utilisation, protein digestibility, body composition
and histopathological changes. The results of the study showed that growth and performance were
significantly affected by the type of plant protein as well as level of inclusion. There was no
significant (P > 0.05) variation in the observed growth responses and feed conversion ratios
among the control diet and the diets containing 25% linseed and 25% groundnut oil cakes. The
diet containing 25% leucaena meal showed the poorest performance. Similar trends were also
observed for protein efficiency ratio and apparent net protein utilisation.