DIETARY EFFECT OF DATE SEED OIL ON THE REPRODUCTIVE PERFORMANCE OF FEMALE AFRICAN CATFISH (Clarias gariepinus) BROODSTOCKS (BURCHELL,1822)

Abstract

The study was carried out to assess the dietary effect of date seed oil on the reproductive performance of Clarias gariepinus broodstock with the average body weight (554.23±3.87g). Date fruit (Phoenix dactylifera) were purchased at Oba market in Akure, Ondo State. The seed were removed from the fruits, sundried, grounded into fine powder and extracted the oil using soxhlet extractor and n-hexane as solvent. Five diets with 40% crude protein were formulated with different inclusion level of Phoenix dactylifera seed oil. Control diet (D 1 ) has 0 g/100g of the feed, while test diets D 2 , D 3 , D 4 and D 5 had 0.5, 1.0, 1.5, 2.0g/100g respectively. The experiment was carried out for a period of 70 days and total number of 30 female C. gariepinus broodstock were randomly distributed into 10 concrete tanks (2 x 2 x 1.25) m3 at a stocking density of three fish per tank in duplicate per treatment. The fish were fed at 3% of body weight twice a day between the hour of 08:00-9:00hr and 16:00-17:00hr and constant water level of 1m was maintained. Each group was batch-weighed every two weeks using a weighing balance. The experimental design was completely randomized design. Water quality parameters which include pH, temperature and dissolved oxygen were determined every week. At the end of the feeding trial, weight gain, gonad- somatic index and reproductive indices (percentage fertilization, hatchability, survival, and fecundity) as well as histological estimation were determined. The fish fed D 3 had the highest weight gain (9452.28±27.22), percentage fertilization (99.83±0.18), hatchability (60.38±4.20) and survival (75.88±19.83), while the weight of the ovaries of the fish fed D 4 had the highest value (171.17±28.34) with fecundity of (11.68±1.85x10 4 ).The control diet D 1 had the lowest in most of the parameters. There was late perinucleus and mature vitellogenic stage in the ovarian histology of the fish fed diets D 2 , D 3 , D 4 and D 5 ,which is the stage of ocyte growth characterized by the formation of egg yolk proteins and their accumulation in the ooplasm compeared with the control diet D 1 which have early perinucleus stage. This study revealed that dietary inclusion of Phoenix dactylifera seed oil improves fertility in Clarias gariepinus which will improve fish seed production.