| THE EFFECTS OF FEEDING ROTIFERS ( BRANCHIONUS PLICATILIS TYPICUS) ON GROWTH PERFORMANCE AND SURVIVAL OF NILE TILAPIA (OREOCHROMIS NILOTICUS) FRY IN OVERCOMING LOW WINTER SEASON TEMPERATURES IN EGYPT |
| FAYED, WALIED M.A., Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria, Egypt, email: fayedwal@gmail.com; Sallam, Ghada R.A., email: fayedgha@gmail.com.
|
| The present study was conducted for six months to assess the effect of feeding Nile Tilapia, Oreochromis niloticus, fry on L-type rotifer, Brachionus plicatilis typicus, during the early feeding stage. Initially, 260,000 fry with average initial body weight (0.46 g) were stocked in 260 1 m3 concrete tanks (1000 fry/tank) for 45 days incubation period, and then transferred to 26 earthen ponds (10,000 fry/pond) for the rest of the six months as wintering period. Rotifers were fed (20, 25, and 30 rotifers/ml) alone to fry and in combination with formulated feed (40% CP, 470 Kcal GE/100g) for the first 4 and 7 days, then formulated feed was offered solely. After the six months study period, the fry fed on rotifers, with concentrations of 20, 25, and 30 rotifers/ml in combination with formulated diet for 7days, expressed high mean final body weight, average daily gain, specific growth rate, and final yield compared to all other treatments. Moreover, the results showed that feeding rotifers to fry increased survival rate during winter season. Thus, this study showed that increasing the concentration of rotifers along with number of feeding days on rotifers, did noticeably improve all fish parameters including protein and lipid body content of O. niloticus fry. Conclusively, primary results revealed the positive effect of feeding O. niloticus fry on rotifers. Therefore, this study recommends that O. niloticus fry should be feed on rotifers for at least 20 rotifers/ml for 7 days in combination with formulated diet.
|
| back |
|
