Effect of monoculture and polyculture systems stocking density on chemical compositions and metabolizable energy of Nile tilapia Oreochromis niloticus and African catfish Clarias gariepinus fingerlings reared in concreted ponds

The proximate physio-chemical analysis of Nile tilapia Oreochromis niloticus and African catfish Clarias gariepinus fingerlings were carried out to elucidate the effect of mono and polyculture systems of different stocking density on chemical compositions quality and metabolizable energy. Fresh samples; (O. niloticus and C. gariepinus) were analysed, the results of the proximate body fish showed insignificance in protein (22.70 and 21.05%) and in lipid 1.16 and 2.63% respectively; among O. niloticus and C. gariepinus and; the dried samples analysis of (tilapia O. niloticus and catfish C. gariepinus); of each treatments (1 Tilapa O. niloticus: 0 Catfish C. gariepinus, 0 Tilapa O. niloticus: 1Catfish C. gariepinus, 1 Tilapa: 1 Catfish, 2 Tilapia: 1 Catfish, 3 Tilapia: 1 Catfish, 1 Tilapa: 2 Catfish and 1 Tilapa: 3 Catfish) at different stocking density 12, 24, 36 and 48 SDfish/m-3 were carried; To detect its effect on (moisture content, crude protein (CP) content, Crude Fat (CF) Analysis, ash content, crude fibre (CF) content, Nitrogen free extracts (NFE) and metabolizable energy (ME). Data analysis using SPSS, One way ANOVA for the results of the proximate analysis of the body fish of monoculture and polyculture; showed that the O. niloticus had the highest level of crude protein (57.75%) in 2T:1C and least (51.46) in 1T:3C compared with; C. gariepinus having the least (50.22) in 1T:1C and highest (54.71%)in 0T:1C. also the results showed the highest crude fat content for C. gariepinus (16.65%) in 2T:1C whilst O. niloticus had the least (9.06%) in 3T:1C. In terms of moisture content (as-dried meat) also, O. niloticus has the highest (8.85%) while C. gariepinus had the least (7.08%). While C. gariepinus had the highest level of metabolizable energy (3001.55 k/Jg-1) and O. niloticus having the least (2743.38 k/Jg-1). In addition, the results showed higher significant different (p<0.01) in crude fibre and; (p<0.05) in crude protein, Nitrogen free extracts, Ash, protein protective value and metabolizable energy of mono and polyculture systems. Results showed that the fish species in monoculture and polyculture systems with different stocking density have an impact on the proximate analysis and quality of fish meat.