Development of an economic breeding objective for Nile tilapia in Nigeria

Abstract

Economic breeding objectives identify the most profitable candidates by weighting trait performance, with economic values, according to each trait’s expected impact on farm profit. Trait preferences amongst farmers also impact breeding objectives, particularly in adoption of genetic material. The production of Nile tilapia (Oreochromis niloticus) in Nigeria has increased in recent years, and as production grows, it is important to consider the genetic merit of the fish. In this study we calculated economic values in Nigerian naira₦ m-2 cycle-1 for feed conversion ratio (FCR;-175.39), growth rate (-1.02), survival (3.41), resilience to low oxygen (1.22) and skin colour (0.4) traits. The economic values were used to design a trait preference trade-off survey, which was deployed across 8 States in Nigeria. Multivariate cluster analysis grouped farmers into 4 distinct trait preference clusters. Trait preference clusters were used to adjust (up or down) the economic values to give new sets of economic values that reflect trait preferences in the respective cluster. Farmers in Cluster 1 prioritize improving fish skin color. Cluster 2 prioritizes FCR, while placing less importance on resilience to low oxygen. Cluster 3 prioritizes survival and low oxygen resilience, while placing less importance on growth. Cluster 4 prioritizes harvest weight and low oxygen resilience. Implementation of a selection index that uses the calculated trait preference adjusted economic values in a breeding program could lead to the development of Nile tilapia strains that are tailored for Nigerian farmer economic conditions and trait improvement preferences.