Comparison between repeatability, reproductive stage stratified repeatability, and relative risk models for prediction of breeding values for functional survival in rotationally crossbred sows

The relative risk and linear repeatability single-trait models for survival between subsequent farrowings predicted equally accurate breeding values (0.02), while the linear repeatability two-trait models for survival from services to their subsequent farrowings and farrowings to the subsequent services predicted more accurate breeding values than the single-trait models (0.04 vs. 0.02). However, the accuracy of breeding values was small for all models because the survival phenotypes used for prediction were censored and the heritability of complete survival times was moderate (8-9%). Therefore, the comparison would benefit from reevaluation in other populations, and the models should be improved upon before implementation in practical breeding programs.