Genetic and Phenotypic Correlations between Aleutian Disease Tests with Body Weight, Growth, and Feed Efficiency Traits in Mink.

The ineffectiveness of vaccination, medicine, and culling strategy leads mink farmers to control Aleutian disease (AD) by selecting AD-resilient mink based on AD tests. However, the genetic background of AD tests and their correlations with economically important or AD-resilient traits are limited. This study estimated the genetic and phenotypic correlations between four AD tests and seven body weight (BW) traits, six growth parameters from Richards growth model, and eight feed-related traits. Univariate models were used to test the significance (P<0.05) of fixed effects (sex, color type, AD test year, birth year, row-by-year), random effects (additive genetic, maternal genetic, and permanent environmental), and a covariate of age using ASReml 4.1. Likewise, pairwise bivariate analyses were conducted to estimate the phenotypic and genetic correlations among the studied traits. Both antigen- and virus capsid protein-based enzyme-linked immunosorbent assay tests (ELISA-G and ELISA-P) showed significant (P<0.05) moderate positive genetic correlations (±SE) with maturation rate (from 0.36±0.18 to 0.38±0.19). ELISA-G showed a significant negative genetic correlation (±SE) with average daily gain (ADG, -0.37±0.16). ELISA-P showed a significant positive moderate genetic correlation (±SE) with off-feed days (DOF, 0.42±0.17). These findings indicated that selection for low ELISA scores would reduce maturation rate, increase ADG (by ELISA-G), and minimize DOF (by ELISA-P). The iodine agglutination test (IAT) showed significant genetic correlations with DOF (0.73±0.16), BW at 16 weeks of age (BW16, 0.45±0.23), and BW at harvest (HW, -0.47±0.20), indicating that selection for lower IAT scores would lead to lower DOF and BW16, and higher HW. These estimated genetic correlations suggested that the selection of AD tests would not cause adverse effects on growth, feed efficiency, and feed intake of mink. The estimates from this study might strengthen the previous finding that ELISA-G could be applied as a reliable and practical indicator trait in the genetic selection of AD-resilient mink in AD positive farms.