Estimates of Genetic Parameters for Lactation Shape Parameters with Multivariate Statistical Technique in Brown Swiss Cattle

This study was conducted to estimate heritabilities of milk yield traits (305-d milk yield, persistency, peak time & lactation curve shape parameters as per Wood model) and two latent variables from Factor Analysis on the basis of 10 test day (TD) milk yield records. Data on pedigree and 504 production records of 272 Brown Swiss cattle were analyzed to estimate genetic parameters with univariate and bivariate animal models. Factor analysis was fitted to 10 TD milk yield records (assumed as independent measures) in order to define lactation curve shapes and two latent variables (FC1 & FC2) were derived from Factor analysis. Kaiser-Meyer Olkin (KMO) measure of sampling adequacy (0.93) and Bartlett’s test of Spherity (P