Not only is fertility important in humans but it is a critical topic in dairy cattle production. An inadequate reproductive performance can compromise farm’s efficiency, profitability, and sustainability. However, why are some animals more likely to become pregnant than others? How could we early identify them? To answer these questions, research was recently conducted at the Livestock Research and Innovation Centre - Dairy Facility (Elora, Ontario, CA) and it was led by Guilherme Madureira, under the supervision of Dr. Eduardo Ribeiro, both members of the Department of Animal Biosciences of the University of Guelph. This research aims to develop an innovative test to detect highly fertile and subfertile females, further contributing to improvements on reproduction and genetic selection of dairy cattle.