the influence of parental imprinting on some economic traits in markhoz goats

Parental effects refer to the phenomenon whereby gene expression is influenced by the parent of origin, a process known as genomic imprinting. these effects may significantly affect phenotypic traits and shape the genetic architecture of individuals, making them an important factor in animal breeding and genetic evaluation programs. this study aimed to examine the impact of parental imprinting effects on genetic variation in a markhoz goat population, with emphasis on body weight traits at birth (bw), weaning (ww), six months (6mw), nine months (9mw), yearling (yw), and yearling fleece weight (yfw). the analysis was conducted in two phases. initially, each trait was modeled using 12 univariate animal models incorporating various combinations of direct and maternal genetic effects. the best-fitting model for each trait was selected using the akaike information criterion (aic). in the second phase, three additional models were constructed by integrating maternal imprinting, paternal imprinting, or both into the selected model, and the resulting changes in aic values were evaluated. the results revealed that including the paternal imprinting effects substantially improved model fit for bw and 9mw, as these models showed the lowest aic values. conversely, for ww, 6mw, yw, and yfw, imprinting variances were negligible, suggesting limited influence of parental origin and supporting the exclusion of these effects from genetic evaluation models for these traits. across all traits analyzed, paternal imprinting effects accounted for 0.7% to 11% of the phenotypic variance, while maternal imprinting effects contributed between 1.5% and 9%. furthermore, incorporating the parental imprinting effects into the analysis led to reductions in both the direct and maternal heritability estimates. these findings highlighted the necessity of accounting for parental imprinting, particularly paternal effects, in genetic evaluation of body weight traits in markhoz goats.