MANIPULATING THE PRODUCTION OF MONO-SEX NILE TILAPIA, OREOCHROMIS NILOTICUS, FRY THROUGH WINTER SEASON

Document Type : Original Article

Author

Department of Animal and Fish Production, Faculty of Agriculture (Saba Basha), 22 Tag Al Roasaa st., saba-basha, boulkly, Alexandria University, Alexandria, Egypt

Abstract

The influence of low temperature on survival rate and growth performance were compared on native fry of mono-sex Oreochromis niloticus to determine how winter season affects the final biomass and production of fry in Egypt. Six diets containing three protein (30, 35, and 40%) and two energy (370 and 470 kcal ME/100 g) levels were offered to fry (1.03g) to satiation, twice daily, for 6 months. At all protein levels, fry fed low-energy diets (370 kcal ME/100g) revealed poor growth and feed conversion efficiency, survival rates, compared to those fed high-energy (470 kcal ME/100g) diets. At dietary protein levels from 35 to 40% crude protein (CP), fish growth and survival rates were significantly improved by increasing dietary energy from 370 to 470 kcal (ME/100g diet). However, the best growth rate and feed utilization were obtained with 40% CP and 470 kcal (ME/100g diet). Body composition was significantly affected by both dietary protein and energy levels. As such, to overcome the low winter season temperatures the O. niloticus fry requires 40% CP and 470 kcal (ME/100g diet) for maximum growth and best survival rate when reared in earthen ponds in Egypt.

Keywords

Main Subjects