Submitted to: Reproduction of Domestic Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2011
Publication Date: 10/11/2011
Publication URL: http://handle.nal.usda.gov/10113/59682
Citation: Safranski, T.J., Ford, J.J., Rohrer, G.A., Guthrie, H.D. 2011. Plenary contribution to International Conference on Boar Semen Preservation 2011. Genetic selection for freezability and its controversy with selection for performance. Reproduction of Domestic Animals. 46(Suppl. 2):31-34. Interpretive Summary: Artificial insemination in pigs is popular compared to other livestock species despite nearly all matings utilizing fresh, diluted semen rather than frozen semen due to the poor fertility resulting from post-thaw boar semen. While breed and line differences are known to exist for sperm freezability in boars, few data are published on the genetics of semen freezing for pigs or its relationship with other production traits. Genetic parameters for post-thaw survival were estimated based on 920 collections from 254 boars in a Landrace-Duroc-Yorkshire composite population. The heritability of percentage of live sperm cells in thawed semen was 0.228 and there was no evidence that selection to improve this trait would negatively affect growth rate or backfat depth. Thus, sperm freezability is an ideal candidate for marker assisted selection or inclusion in traditional selection programs if the industry wants to improve this trait.
Technical Abstract: Little data are available in the literature regarding freezability of boar sperm or its relationship with other traits. Existing data suggest the trait would respond favorably to selection, and information is available from other species suggesting components which might have changed. Genetic parameters are estimated for boar sperm freezability including heritability and correlations with other production traits. Sperm freezability is an ideal candidate for marker assisted selection or selection for favorable alleles.