Effect of Stocking Density on Growth Performance of C. gariepinus and Breeding Values for Key Economic Traits from Three Eco-Regions in Nigeria: River Niger (N), River Benue (B) and River Hadejia (H)

The researched was practically investigated with the objective on effect of stocking density on growth performance and breeding values for key economic traits in crosses between broodstock from three eco-regions: River Niger (N), River Benue (B) and River hadejia (H). Growth parameters were determined using a weighing scale (weight) and a metre rule (length). Parameters determined after six months (2 stocking densities: 30fish.m-2 and 60 fish.m-2). Economic traits that were determined after 6 months of growth include: total length (TL), standard length (SL), body depth (BD) and head length (HL). Breeding values for final weight, final total length, final standard length, final body depth and final head length were determined based on narrow sense heritability estimate using the model of additive genetic variance. To estimate the variance components and breeding values of cross from broodstock of various ecoregions, the animal model in the R package breedR was used. Breeding values were then used to agglomerate offspring and determined which economic traits best explain the variation in the populations using principal component analysis in R. Under culture for 6 months, MFW differed among the crosses regardless of stocking density (p<0.05). The MFW ranged from 415.16g (♀H×H♂) to 733.78g (♀H×N♂). The narrow sense heritability (h2) was higher for body depth in progenies reared at low stocking density (0.1515) compared to those reared at high stocking density (0.0697). The breeding values for final weight and body depth was significantly impacted by both stocking density and cross (p<0.05). In conclusion, selective breeding for economic traits yields breeding values in the first generation of selection. Heritability for body depth was highest at low stocking density compared to high stocking density.