The study tested different models to see which one is best for predicting early pregnancy in animals using genetic data. They found that the probit/probit and logit/logit models were more accurate than the logit/probit and probit/logit models. These better models gave estimates closer to the actual genetic heritability and had higher correlations between predicted and true values. The probit/probit and logit/logit models also performed better in ranking the top breeding animals. Overall, using the right model is important for accurately predicting genetic traits in animals.