Abstract:
In commercial fish farming fish feeding is a major concern and it is an essential
factor affecting the profit of the farm. In intensive farming systems especially
formulated diets with high protein content should be provided. Such protein levels
can be achieved by incorporating fishmeal. Since fishmeal is comparatively costly
and not available readily, researchers are ought to investigate substitute for
fishmeal, from by products of food processing and/or milling. It is also important
to know the diurnal changes of food digestibility of fishes and that information can
be used to improve husbandry practices. The present study was carried out
basically to evaluate the feasibility of developing low cost diet for Oreochromis
niloticus through investigation on the suitability of Neem meal powder as a
substitute for fishmeal and to determine the digestibility time and the best time for
faeces collection. Research was carried out with two size group of (). niloticus
(body weight 7.00-9.00 g: group A and 10.00-14.00 g: group B). Fish were fed
with a reference diet and two test diets incorporated with Neem meal of two
qualities. Test diet incorporated with low protein level Neem meal known as TDN1
and test diet with high protein Neem meal known as TDN2. Fish were fed to
satiation twice a day at 0800 and 1700 hr. Faeces were collected four times a day at
0800, 1100, 1400 and, 1700. Digestibility values for three diets were determined by
the Cr2O3 method. Dry matter and protein digestibility of TDN2 is higher than that
of reference diet and TDN1 for group B fishes. Similarly, protein digestibility of
TDN2 in group B fish was higher than that of reference diet and TDN1. Faeces
collected at I700hrs showed significantly different (P < 0.05) higher level of dry
matter and protein digestibility than other faeces collected time. It can be
concluded that the Neem meal with high protein level is a better substitute
ingredient for fish meal when compared to low protein level Neem meal.
Furthermore, observation made during the present study on best digestibility times
indicate that the best time for collecting faeces for digestibility studies in ().
nilolicus is between 1400-1700 hrs.
