Sixteen weeks feeding experiment was conducted in net enclosures to study
the effect of dietary kochia (Kochia indica) dried leaves and buds (KOLB) together
with different unconventional protein sources on growth performance, feed utifization
and carcass composition of blue tilapia (Oreochromis aureus). Two dietary levels of
KOLB (15 and 30 %) were used with four protein sources [fish meal (FM), poultry
viscera meal (PVM) yeast and the basal diet protein]. Forming eight isocaloric diets,
approximately 23 % crude protein, were fed to duplicate groups of fish (initial weight
15.5 g) at a daily rate of 2.5 % of their body weight. The results revealed that growth
performance and feed utilization of fish fed on 15 % KDLB diets were significantly
higher than that fed 30 % KOLB diets. Feed conversion ratio of fish received the diets
contained fish meal surpassed the other groups, followed by those received PVM
then yeast and finally the basal diet. There were insignificant (P > 0.05) differences
between fish fed diets contained FM or PVM in feed intake, PER, PPV and EU, While,
significant differences were noticed between fish fed the diets contained yeast and
those fed the basal diets. Body composition of fish was affected by dietary KOLB
levels and protein sources. Moreover, the economical analysis of the tested diets
indicated that inclusion of 30 % KOLB with PVM into the diet was the best, followed by
that contained 15 % KOLB with PVM compared to the other tested diets. These data
suggested that the inclusion of 15 % KOLB with poultry viscera meal could be used
in the diet of blue tilapia without any adverse effect on either growth performance or
feed and nutrient utilization compared to FM diets.