title: Genetic parameters for chronic progressive lymphedema in Belgian Draught Horses.
abstract: Genetic parameters for chronic progressive lymphedema (CPL)-associated traits in Belgian Draught Horses were estimated, using a multitrait animal model. Clinical scores of CPL in the four limbs/horse (CPLclin ), skinfold thickness and hair samples (hair diameter) were studied. Due to CPLclin uncertainty in younger horses (progressive CPL character), a restricted data set (D_3+) was formed, excluding records from horses under 3 years from the complete data set (D_full). Age, gender, coat colour and limb hair pigmentation were included as fixed, permanent environment and date of recording as random effects. Higher CPLclin certainty (D_3+) increased heritability coefficients of, and genetic correlations between traits, with CPLclin heritabilities (SE) for the respective data sets: 0.11 (0.06) and 0.26 (0.05). A large proportion of the CPLclin variance was attributed to the permanent environmental effect in D_full, but less in D_3+. Date of recording explained a proportion of variance from 0.09 ± 0.03 to 0.61 ± 0.08. Additive genetic correlations between CPLclin and both skinfold thickness and hair diameter showed the latter two traits cannot be used as a direct diagnostic aid for CPL. Due to the relatively low heritability of CPLclin , selection should focus on estimated breeding values (from repeated clinical examinations) to reduce CPL occurrence in the Belgian Draught Horse.
authors.affiliation: KU Leuven Department of Biosystems, Livestock Genetics, Leuven, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: De Keyser
authors.forename: S
authors.initials: S
authors.lastname: Janssens
authors.forename: L M
authors.initials: LM
authors.lastname: Peeters
authors.forename: N
authors.initials: N
authors.lastname: Foqué
authors.forename: F
authors.initials: F
authors.lastname: Gasthuys
authors.forename: M
authors.initials: M
authors.lastname: Oosterlinck
authors.forename: N
authors.initials: N
authors.lastname: Buys
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001530:Belgium; D018450:Disease Progression; D006734:Horse Diseases / Q000235:genetics* / Q000473:pathology; D006736:Horses; D008209:Lymphedema / Q000235:genetics / Q000473:pathology / Q000662:veterinary*
keywords: Draught horse; chronic progressive lymphedema; hair diameter; heritability; skinfold thickness