To create a technical mating, select Technical Mating when adding a mating. This allows you to create a mating with a host dam and a sample/embryo.
Once technical mating is selected, you will need a host dam (if it is not already selected).
Select the sample or embryo you are using from the dropdown menu, and set up the rest of the mating as usual.
Click here for an example of a technical mating from the demo system.