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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Genetics and Animal Breeding » Research » Publications at this Location » Publication #325228
Title: Estimating heritability of wool shedding in a cross-bred ewe population

Author
item JURADO, VARGAS - University Of Nebraska
item Leymaster, Kreg
item Kuehn, Larry
item LEWIS, RON - University Of Nebraska

Submitted to: Journal of Animal Breeding and Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2016
Publication Date: 5/1/2016
Publication URL: http://handle.nal.usda.gov/10113/5507947
Citation: Jurado, Vargas N., Leymaster, K.A., Kuehn, L.A., Lewis, R.M. 2016. Estimating heritability of wool shedding in a cross-bred ewe population. Journal of Animal Breeding and Genetics. 133:397-403. doi:10.111/jbg.12215.

Interpretive Summary: Shearing of wool represents a significant expense to sheep producers with little opportunity to recover the cost due to low wool prices, particularly for meat sheep breeds that typically have lower quality wool. Producers can circumvent these costs by using breeds of sheep that naturally shed their wool fleece each year. However, some of these breeds have less desirable fertility and growth characteristics. In the development of a composite line with improved fertility and growth where sheep had variation in their ability to shed wool, we were able to show that selection for increased shedding was feasible with a heritability estimate of 0.256. Weight would not be adversely affected through selection to increase wool shedding.

Technical Abstract: Low wool prices and high production costs in sheep systems have resulted in the introduction of hair sheep genetics into flocks to reduce shearing costs. Wool shedding occurs naturally in a few breeds, and can be incorporated by crossbreeding. The opportunity to enhance shedding through selection depends on the extent of genetic variability present. Genetic and environmental parameters for wool shedding for ewes from a three-breed composite population were estimated using Bayesian inference. Data on 2025 crossbred ewes, including 3345 wool shedding scores (WS) and 1647 breeding weight (BW) records, were analyzed using bivariate and, for WS, univariate animal repeatability models. Breeding weight was included to account for possible selection bias. Breeding weight was moderately heritable and highly repeatable with means of 0.317 and 0.724, respectively. Under both models, WS was found to be moderately heritable and repeatable with means of 0.256 and 0.399, respectively. Based on a cumulative link model and contingency table analysis, age and reproductive activity influenced the extent of WS (P < 0.05). Given that WS is moderately heritable, selective gain in WS can be achieved.