EFFECTS OF DIETARY SUPPLEMENTATION OF DATE PALM (Phoenix dactylifera L.) SEED ON EGG QUALITY OF AFRICAN CATFISH (Clarias gariepinus) BROODSTOCKS

Abstract

The effects of Phoenix dactylifera seed powder on the egg quality of Clarias gariepinus broodstocks were investigated. Broodstocks weighing 323.40 ± 2.55g - 340.81 ± 1.57g was used for this study. Five iso-nitrogenous diets with 40% crude protein were formulated with graded inclusion levels of date palm at 0, 0.5, 1.0, 1.5; 2.0g/100g was used for this study of diet designated as D1, D2, D3, D4 and D5 respectively. A total of 75 female Clarias gariepinus broodstocks were randomly distributed in triplicate into 15 concrete tanks (1m × 1m × 0.6 m) at stocking density of 5 fish per tank. The experiment was carried out for 70 days and the broodstocks were fed at 3% body weight. Reproductive performance indices (%fertilization, %hatchability and %Survival) and egg quality parameters (Relative Fecundity and Egg diameter) was determined at the end of the feeding trial. There was no significant differences (P<0.05) in the weight of ovaries, relative fecundity, and gonadosomatic index in all the experimental diets. The ovary weight (80.40 ±7.40g) was highest in D3. Percentage Fertilization (94.39%±0.75) and Percentage hatching (89.70%±2.97) was highest in fish fed diet D4 (1.5 g date palm/100 g diet) and %Survival was highest in D5 (2.0 g date palm/100 g). The result revealed that dietary supplementation of P. dactylifera seed powder at 0.5 – 2.0 g/100 g diet appreciably increased the percentage fertilization, Percentage hatching and survival of the hatchlings. The result from the histological studies carried out indicated that the ovary of fish fed diets D1 and D3 showed few immature oocytes and ripe oocytes with a visible oocyte periomileolar stage. Also, the ripe ovary of C. gariepinus female fish fed on control diet composed mainly necrotized seminiferous tubular lumen and few lobules. Fish fed D2 (0.5 g date palm/100 g of feed) showed primary oocytes and oocytes with primary yolk accumulation with few matured oocytes. The findings revealed P. dactylifera seed powder as a promising pro-fertility agent which could be exploited in fish seed production