Effect of varying dietary crude protein levels on spawning frequency and growth of Sarotherodon niloticus breeders

Abstract

Four-month-old S. niloticus breeders were fed with dry pellets containing 20 to 50% crude protein in two separate experiments. Their frequency of spawning and their growth in length and weight were determined over a 16-week period for each experiment.

Spawning frequency and total growth (body weight gain plus total weight of eggs collected) of females had a tendency to increase as the dietary crude protein level increased to 50%. However, there were no significant differences (P0.05) among mean spawning frequencies and mean numbers of eggs per spawning. Although better growth was obtained with higher dietary crude protein, there was no significant correlation between a brooder’s weight and the number of eggs spawned each time.

There was an increase in mean weight gain of the males as the dietary crude protein increased up to 50%. Weight gains of fish fed with 50% crude protein were 48.7% and 73.8% greater in Experiment I and II, respectively, than those fed with 20% crude protein.