Analysis of Covariance Structure of Repeated Measurements in Holstein Conformation Traits

A model was proposed and tested for explaining observed structures of (co)variances for a multiply measured conformation trait, final type score, in Holstein cattle. Typically, second and later measures on the same animal showed increased variance and covariance. A maximum likelihood approach was developed that considered correlated error relationships among measures as a way of explaining observed structures in phenotypic (co)variances. Developed procedures explained observed structures and facilitated estimation of individual variance and residual variance components.