304 Genetic trends for reproductive traits in American mink. (7th December 2018)

• Record Type: Journal Article
• Authors: Karimi, K; Sargolzaei, M; Wang, Z; Plastow, G; Miar, Y
• Is Part Of: Journal of animal science. Volume 96(2018)Supplement 3
• Page Start: 115
• Page End: 116
• Publication Date: 2018-12-07
• Subjects: Genetic trend -- American mink -- litter traits; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/sky404.253
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: Data on 3, 046 litters collected from the Canadian Centre for Fur Animal Research (CCFAR) at Dalhousie Faculty of Agriculture from 2002 to 2016 was used to investigate the genetic trends of reproductive traits in American mink. Reproductive traits included total number of kits born (TB), number of live kits at birth (LB), number of live kits at weaning (LW), survival rate at birth (SB), survival rate at weaning (SW), gestation length (GL), average litter weight at birth (AWB), average litter weight at week three (AW3) and average litter weight at weaning (AWW). Bivariate models fitting random effect of permanent environment, covariate (sex ratio) and fixed effects (year, age of dam, number of mating, colour-type, origin of dam, and number of live kits) were used to estimate breeding values using ASREML 4.0. The genetic trends were estimated by regression of breeding values on birth year of animals. Low heritabilities (±SE) were estimated for TB (0.07 ± 0.03), LB (0.07 ± 0.02), LW (0.09 ± 0.04), SB (0.13 ± 0.03), SW (0.10 ± 0.02), AW3 (0.19 ± 0.04) and AWW (0.10 ± 0.04). Moderate heritability estimates were observed for GL (0.29 ± 0.03) and AWB (0.28 ± 0.05). Genetic trends of survival rates at birth and weaning were favorable from 2002 to 2009. However, no progress was observed for these traits after 2009. A remarkable decrease was observed in genetic trend of survival rates in 2014 due to an Aleutian disease outbreak in this timeframe. No relevant progress was observed for genetic trends of AWB, AW3 and AWW. Minor fluctuations in genetic trends of TB, LB and LW were unfavorable. Additionally, genetic trend of GL was not changed during this timeframe. These results indicated that phenotypic selection was not an effective method to improve the genetic merit of reproductive traits during 2002–2016. Phenotypic selection should be replaced by genetic and genomic selection strategies to improve reproductive traits in mink farming.