Association of diversity in microsatellite genotypes with layer traits in Rhode Island Red chicken

Development of vast varieties of high-yielding commercial poultry germplasm can be attributed to rapid selection and controlled breeding. However, their maximum genetic production potential has not been achieved so far. The present study was conducted to analyze polymorphisms in egg production associated microsatellite markers in the sampled population of the selected strain of Rhode Island Red (RIR) chicken and to determine the association between various genotypes of polymorphic markers and layer production traits. One hundred and eleven pullets belonging to five hatches of RIR, maintained at the institute’s farm were used and data on body weight at 20 weeks of age (BW20) and layer economic traits. Age at sexual maturity (ASM), egg weight at 28 and 40 weeks of age (EW28, EW40) and egg production up to 40 weeks of age (EP40) were analyzed by least squares analysis of variance taking sire as random and hatch as fixed effects. Average ASM and EP40 were 135.19±1.15 days and 124.55±1.94 eggs, respectively. The BW20 revealed low, but positive genetic as well as phenotypic correlations with EP40 thereby suggested its usefulness as a selection criterion for genetic improvement of egg production. All egg production-associated microsatellite loci revealed polymorphism and exhibited a prevalence of heterozygosity. The studied population demonstrated Hardy-Weinberg disequilibrium. Genotypes at two microsatellite loci ADL0023 and ADL0273 demonstrated significant effects on layer economic traits suggesting the probable usefulness of these microsatellite markers polymorphism in marker-assisted selection for genetic improvement of egg production in RIR chicken.