http://indexmedicus.afro.who.int Hybridations des taxons Oreochromis niloticus (Linnée, 1758) aux taxons Tilapia guineensis (Bleeker, 1862) et Sarotherodon melanotheron (Rüppell, 1852) dans les étangs de la station aquacole de Layo (Côte d'Ivoire)

This is a comparative study for understanding the low fish production in the Goh region (Central-Western of Côte d'Ivoire) through the management of the five main fish farms. The study was carry out during 35 days, from August to September 2017. The farmers were all over 45 years old men and sexing fish late. The by-products (rice bran and low flour) were used for feeding on all farms, but only Bahompa 2 farm, makes a supplement with the industrial granulated food. Fish growth parameters have been taken with 200 individuals of Oreochromis niloticus per farm (1000 fish). The main performance indicator such as Daily Weight Gain (DWG), Specific Growth Rate (SGR) and relative condition factor (K) have been calculated for each farm. The best performance of the fish have been recorded on the Bahompa 2 farm (DWG= 1.54 ± 0.47 g/day, SGR = 2.04 ± 0.36%/day and K = 1 ± 0.01. Yopohoué farm follows, with DWG = 1.18 ± 0.31 g/day, SGR = 1.81 ± 0.3%/day, and K = 1 ± 0.01. Bahompa 3 farm were third with DWG= 0.89 ± 0.72 g/day, SGR = 1.15 ± 0.46%/day and K = 0.99 ± 0.04. Bahompa 1 farm, were fourth with DWG = 0.68 ± 0.19 g/day, SGR = 2.02 ± 0.41%/day and K = 1 ± 0.1. Then Sanepa farm were the last with DWG = 1.11 ± 0.18 g/d SGR = 1.21 ± 0.11%/day and K = 1 ± 0.98. The allometric coefficients (b <3) reflect the slow growth of these fish. These low parameters indicate living stress of Oreochromis niloticus fishes during their breeding.