The exploration of additive genetic variance for the selection of animals is the central paradigm in quantitative genetics and it is important to use appropriate animal models considering important factors. This study compares various factor effects for heritability and breeding values estimations on data collected on the Corriedale. Overall, the heritability estimates were highest for birthweight. Both the additive genetic variance and the heritability got reduced upon adding more random effects. Year-effect as random reduced the heritability except for birthweight. The highest average accuracy for breeding values for birth, weaning, 6, 9, and 12-month-weights for were 0.656, 0.567, 0.519, 0.486, and 0.515. These were observed for models having sex or sex and parity as fixed effects. It is concluded that fixed and random factors have a significant effect on genetic-factors and breeding-value accuracies and should be considered during selection programs. Such farm-specific models shall make the selection program more effective.