Dealing with Multicollinearity in Predicting Egg Components from Egg Weight and Egg Dimension

Measurements of 174 eggs from meat-type breeder flock (Ross) at 36 weeks of age were used to study the problem of multicollinearity (MC) instability in the estimation of egg components of yolk weight (YKWT), albumen weight (ALBWT) and eggshell weight (SHWT). Egg weight (EGWT), egg shape index (ESI)=egg width (EGWD)*100/egg length (EGL) and their interaction (EGWTESI) were used in the context of un-centred vs centred data and principal components regression (PCR) models. The pairwise phenotypic correlations, variance inflation factor (VIF), eigenvalues, condition index (CI), and variance proportions were examined. Egg weight had positive correlations with EGWD and EGL (r=0.56 and 0.50, respectively; P