HGG Community Forums

You can use straws from the mare's page. Head on over to her control panel, set something as a breeding fee (it doesn't especially matter what, since you are basically paying yourself the fee - you probably want to set it to more than, say, 2500 or someone might use the mare on you during the brief window where she's up for breeding.)

Then go back to the Horse Info tab and press the new Breed To This Horse button that appeared. The SECOND set of dropdowns should show your list of straws; pick whichever one, enter a foal name, real or temporary, and voila.

This is also how you use straws with mares on the public brood board. :D