Browsing by Subject "litter size"

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  • Häkli, Katja (Helsingfors universitet, 2013)
    The objective of this study was to estimate genetic parameters of minks Aleutian Disease (AD) infections and investigate the genetic relationships between Aleutian Disease infection and fertility traits. The research data was obtained from the Finnish Fur Breeders Association. The data had information from one mink farm in years 2006-2010. The data contained 27 753 one year old female minks. Only those females who had more than three kits were tested. There were 18 478 tested minks of which 9.2 % had AD. The pedigree data had 41 573 animals. In this study AD infection, pregnancy and felicity were binary traits. AD inf. 1 = sick, 2 = healthy. If female had kit(s) or aborted or lost her kit(s) after birth, pregnancy (PREG) = 2, otherwise = 1. If female lost her kits after birth, felicity (FEL) = 1. If litter size were at least one, FEL = 2. The heritability estimates and variance components (REML) were calculated using multi trait animal model and DMU-software. Heritability estimates for the studied traits were low: 0.07 for AD infection, 0.07 for PREG, 0.04 for FEL and 0.08 for litter size. The heritability estimate for AD was smaller than the common litter variance for the trait. Genetic correlations between AD inf. and FEL, and AD inf. and litter size were positive. The genetic correlations between AD inf. and FEL were 0.447 ± 0.132 and between AD inf. and litter size 0.290 ± 0.108. The results suggest that resistance for AD inf. has genetic variation. Although the heritability estimate for the trait was low, it can be affected by selection. Genetic correlations between AD inf. and fertility traits were favourable. Selection for larger litter size could increase mink resistance for AD infection.
  • Niemi, Jarkko; Bergman, Paula; Ovaska, Sami; Sevon-Aimonen, Marja-Liisa; Heinonen, Mari (2017)