Genetic Parameters of Immune Traits in Dairy Cattle

Abstract Text:

Previous work has identified a number of immune traits which are associated with dairy cow health. The purpose of the present study was to determine the genetic parameters of these immune traits. Blood samples were collected from 465 Holstein-Friesian dairy cattle and analysed for 13 different serological and cellular immune traits. Data were modelled using a repeatability mixed linear model. Heritability estimates and the variance components were obtained and ranged from 0.147 (NAb KLH) to 0.497 (CD4⁺). Heritability of the T cell subsets was highest with 0.497, 0.250 and 0.314 for CD4⁺, CD8⁺ and CD4⁺:CD8⁺ ratio respectively. Furthermore, the ratio of permanent environmental variance to total phenotypic variance (c²) was estimated and ranged from 0.028 (%Eosinophils) to 0.623 (TNF-α). Finally, the repeatability of each trait was estimated and ranged from 0.207 (NAb KLH) to 0.701 (CD8⁺).

Keywords:

dairy cattle

immune traits

heritability

genetics