THE GROWTH PERFORMANCE OF Oreochromis niloticus FED GRADED LEVELS OF MUSSEL, Mytilus edulis SHELL AS POSSIBLE REPLACEMENT FOR DI-CALCIUM PHOSPHATE

Abstract

This study was undertaken in order to evaluate the effect of the inclusion of Mytilus
edulis shell (Mussel Shell Meal) collected from the Lagos Lagoon, University of Lagos
Lagoon Front, in diets of Nile tilapia (Oreochromis niloticus), on the growth performance of the fish. Ten fingerlings each of 0. niloticus were placed in plastic tanks and fed for 12 weeks with feed containing grinded M. edulis shell substituted for Di-calcium phosphate (DCP) at the rate of 0% (Tj, the control diet; 25% (T); 50% (T); 75% (T) and 100% (T). Each feeding regime was in triplicates. The mean water parameters during the experimental period were within the normal range for tropical fishes. Mean temperature was within the range of 27. 780.57C to 28.170.57C, while hydrogen ion concentration ranged from 7.340.07 to 7.4 90.1 O. The dissolved oxygen level ranged from 6. 190. 633mg/1 to 6.4 60. 633111g/ I. The proximate analysis of M edulis shell showed a higher crude protein content compared to DC? Fishes fed with diet 4 (T) recorded the highest value of mean weight gain (MWG= 7. 613,34); protein efficiency ratio (PER= 6.743.34) and daily rate of growth (DRG= O. 090. 00). The control diet I (T jrecorded the highest value in voluntary food intake (VFI= 0.380.01), and lowest food conversion ratio (FCR=
1.540.85). This study showed that-at 50 -100% level of substitution ofDi-calcium phosphate with M edulis shell in the diet, 0. niloticus had better growth performance. The higher rate of returns, benefit cost ratio and profit index were achieved in 75- 100% inclusion.