EFFECT OF DIFFERENT FEEDING REGIMES ON REPRODUCTIVE PERFORMANCE AND LARVAE PRODUCTION OF BLUE TILAPIA (Oreochromis aureus) BREEDERS.

Effect of different feeding regimes, depending on fed fat levels and/or protein
energy ratio (P:E), during rest and ovulation phases, was investigated, in the present
study, on reproductive performance and larvae production of blue Tilapia
(Oreochromis aureus) breeders. Two diets were formulated and supplemented to
experimental fish groups; the first fish group was supplemented feed (I), low fat diet
(4.56%), (protein: energy ratio: 67 mg/kcal), during ovulation phase, then feed (II), rich
fat diet (9.13%), (P:E ratio: 58.4 mg/kcal) was supplemented to the same fish group in
resting phase as long as 7 days. The second fish group was supplemented with feed
(II) only allover the experimental period extended for 112 day.
The results revealed that there is a considerable difference (P?O.05) in food
and nutrients requirements before and after fish broodstock ovulation. The best egg
and larvae production (12184 egg/kg female) was obtained by using the first feeding
regime; feed (I), after the beginning of ovulation phase, and then feed (II)
supplementation in the rest phase. In the second experimental fish group, females
. were fed allover the experimental period, fat rich diet (9.13%) only (second feeding
regime). Egg production in that group was observed to be less (8953 eggs/kg female)
than the first group. This result may be attributed to fat accumulation on the internal
organs, especially ovaries that hinder normal process of reproduction.
It could be concluded that not only feeding of spawners plays a considerable role in
reproductive performance, but also stage of spawning feeding requirements is
important in operating succeeding spawning.