Akademik Veri Yönetim Sistemi
Veterinarija ir Zootechnika, cilt.82(1), ss.99, 2024 (Scopus)
The effective application of major gene analyses in animal breeding programmes allows for the production of animals with desirable genetic traits in a more efficient and healthy manner. Therefore, the use of major gene analyses is considered an important strategy in animal breeding. This study aims to detect the presence of major genes in the body weight phenotype of hair goats using Bayesian segregation analysis. In this study, 6108 body weight records from 2589 animals were utilised. The mixed inheritance model assumes that genetic variance can be explained by both a major gene and polygenic factors. The segregation analysis model allows for the investigation of a major gene through Bayesian segregation analysis in the presence of pedigree data [1]. This study examined whether a major gene with two alleles (A1 and A2) and frequencies of (1-q) and q, respectively, is associated with body weight in the population. Major locus genotypes were considered as A1A1, A1A2, and A2A2. Due to Hardy-Weinberg equilibrium, the alleles were assumed to combine independently with frequencies (1-q)2, 2q(1-q), and q2. The polygenic model and the relevant inference can be derived from the interaction of “genotype means * design matrix * matrix containing each individual's genotype.” Segregation analysis was performed using the IBAY computer programme [2]. The presence of a major gene in the relevant phenotype was determined by examining whether the highest posterior density regions (HPDR) contained 0 and by assessing Mendelian transmission probabilities. Accordingly, for the birth weight trait, the posterior means (± SD) of the heritability were estimated as h2 = 0.51 (± 0.56) using the polygenic model and h2 = 0.81 (± 0.91) using the major gene model. It was observed that the heritability estimate for the major gene model was higher than that for the polygenic model.