Age of the dam, permanent environmental and maternal genetic effects on weight at 90 days of Pirenaica calves

the aim of this thesis is to model the maternal effects with a random regression model associated with age of the dam of the recorded calf. This model will allow to describe the evolution of the maternal genetic variances along the productive lifespan of the cows and to predict the maternal genetic effect of each individual (cow or dam) at several age points. My study attempts to examine the evidence for the existence of relative-size maternal effect measurements of genetic and environmental components of maternal effects and to determine whether covariation exists between maternal capacity and environmental factors influencing expression phenotypic of the weight at weaning, the only reference feature in this study.