When you click under Cow Day Entry on 04. Insemination/mating you will come to the Animal Selection Screen.

In this screen, the first thing you will see by default are the Attention Animals. By clicking on the All animals button, you can also retrieve a list of all animals.

Which animals exactly appear on the attention list depends on the values that have been set. To view these values, click on the settings button in the top right of the screen.  

In the screen that opens you can indicate from when you want the animals to appear on the attention list and save these