EVALUATION OF POULTRY BY-PRODUCT AND EARTHWORM MEALS AS PROTEIN SOURCES FOR TILAPIA FISH

In this study two experiments were conducted to test the possibility of replacing fish meal protein partially or completely by other protein sources in the commercial diets of tilapia (O.niloticus). These were, the poultry by-product meal (PBPM) and the dried earthworm meal (EWM). In the two experiments, fish meal protein was substituted by poultry by product meal protein (PBPM) in the first one and earthworm meal protein (EWM) in the second at an levels of 0, 25, 50, 75 & 100% for the two products In each experiment, 150 O.niloticus fish were divided into equal 10 groups (15 fish/group) and the fish were fed to satiation on the experimental diets for 60 days.
In the first experiment, there was nogreat difference between diets containing 25% and 50% PBPM and their performance was better than the control diet, 75% and 100% PBPM. Feed intake was decreased in fish groups fed on the high levels of PBPM replacement (75 & 100%). Protein efficiency ratio (PER) and protein retention of the fish group fed on 25% and 50% PBPM were higher than the control group and the lowest values with 100% PBPM substitution. Apparent protein digestibility (APD) in the diets did not differ greatly and varied from 75% to 849.
In the second experiment, feed intake was decreased in fish groups fed on the all diets including EWM when compared to the control group fed on the fish meal. Fish fed on the control diet had the highest growth rate and feed utilization, while those fed on 100% EWM protein diet were the poorest. The PER & APD of the control group were higher than for fish fed on EWM protein diets.
It could be concluded that, the protein of PBPM could be improved when it replace partially of fish meal protein, while the use of
EWM has adverse effects on the productivity of fish even at low percentage.