Application of genotype sensitivity to selection between two exotic strains of chickens in humid tropical environment

Abstract

Genotype sensitivity as a change in the relative performance of a genotype in the presence of two or more environments could be an important factor in the breeding of exotic birds in the tropics. Farm records covering 10 years (1999 - 2008) were employed to study the effect of seasons on genotype sensitivity and their usability for selection in the breeding of exotic Parent stock chickens of Bovan and ISA origins in South-West Nigeria. Cock weight, hen weight, Hen-day production, egg weight, fertility of eggs set, hatchability of eggs set and pullet day-old chicks hatched were examined. Sensitivity analysis was conducted using the regression procedures of Microsoft Excel, 2007. Results revealed a lack of significant difference between genotypes in sensitivity indices within seasons, in body weight, HDP and egg weight. Due to Interaction between genotypes and seasons, the genotype sensitivity values demonstrated lack of definite pattern with the output levels of FES and HES between genotypes. Genotype sensitivity in the presence of genotype – season interaction, could be reliable for making choices between chicken genotypes in the humid tropics, especially in early dry season.