Heritability estimates and response to selection for growth of Nile tilapia ( Oreochromis niloticus) in low-input earthen ponds

• Published in: Aquaculture 2006-11, Vol.261 (2), p.479-486
• Main Authors: Charo-Karisa, Harrison, Komen, Hans, Rezk, Mahmoud A., Ponzoni, Raul W., van Arendonk, Johan A.M., Bovenhuis, Henk
• Format: Article
• Language: English
• Subjects: 8 strains; Animal and plant ecology; Animal aquaculture; animal growth; Animal productions; Animal, plant and microbial ecology; Aquaculture; atlantic salmon; Biological and medical sciences; Body weight; Brackish; Breeding value; farmed tilapias; fertilized ponds; fish; fish culture; fish ponds; Fresh water ecosystems; freshwater aquaculture; freshwater fish; Fundamental and applied biological sciences. Psychology; General aspects; genetic-improvement; Heredity; Heritability; mass selection; mortality; Nile tilapia; Oreochromis niloticus; Ponds; rainbow-trout; Selection response; survival; Synecology; Tilapia; tilapia (common name)
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2006.07.007

This study presents results of two generations of selection (G 1 and G 2) for growth of Nile tilapia. The selection environment consisted of earthen ponds which were fertilized daily with 50 kg dry matter (dm)/ha chicken manure. No supplementary feeds were provided. In total, 6429 fully pedigreed experimental fish were included in the analysis. Survival till harvest was highly variable ranging from 35% to 77% and was affected by initial weight, pond, and age effects. Body weight at harvest (BW) increased from a mean of 67.4 g in the grandparental (unselected) population (G 0) to 129.5 g in G 2 was affected by initial weight, pond, sex and age effects. Generations were discrete and therefore genetic parameters were estimated separately for each year. Heritability estimates for BW ranged from 0.38 to 0.60, and the heritability for survival ranged from 0.03 to 0.14. The estimated selection response was 23.4 g (34.7%) between G 0 and G 1 and 13.0 g (14.9%) between G 1 and G 2. These results demonstrate the feasibility of selection for growth of Nile tilapia in low-input environments.