on reproductive traits in Warmblood horses. Can. J. Anim. Sci. 89: 215Á218. Reproductive efficiency is an important issue in horse breeding. However, almost no estimates of genetic parameters of reproductive traits in horses can be found in the literature. The objective of the study was to estimate heritability and genetic trends of foaling rate and number of reproductive seasons in Warmblood horses. The records of 3965 mares from six studs were analyzed. Mares were on average kept for 7.3 reproductive seasons with a foaling rate of 66%. Models included fixed effects of stud, period of birth, breed and random additive genetic effect. Heritability estimates were 0.12 for foaling rate and 0.17 for number of reproductive seasons.
Data on 4477 mares born between 1932 and 1995 from six studs were recorded. Three exterior traits were included: height at wither, chest girth, circumference of cannon. (Co)variance components were estimated by the DFREML procedure on the basis of four linear models. Model I included the fixed effects: period of birth, place of birth, breed effect (as covariable) and random effects: direct additive genetic and residuals. Model II was expanded by taking into account the maternal additive genetic effect. Third model included cytoplasmic effect as fixed (model IIIa) and random (model IIIb). Direct heritability estimates varied from 0.4 to 0.6 whereas maternal heritability estimates ranged between 0.01 and 0.25, cytoplasmic heritabilities were close to zero. Negative correlations between direct and maternal effects were estimated for all traits under study. Akaike Information Criterion suggested the highest adequacy of model I. However, other criteria (likelihood ratio test and error variance estimate) and negative covariance between direct and maternal genetic effects indicate that maternal effects should be included in the genetic evaluation of horses. In general, genetic trends were positive for the traits studied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.