In the study, they wanted to see how heparin affects bull and stallion sperm. The researchers mixed heparin with sperm and saw how they moved and reacted over time. Both bull and stallion sperm became less mobile with time, but stallion sperm reacted the same with or without heparin. However, stallion sperm reacted more to a substance called A23187 when heparin was present. Both bull and stallion sperm showed more reaction to A23187 after being treated with heparin, suggesting they went through a process called capacitation. Bull sperm needed less heparin to get capacitated compared to stallion sperm, requiring more heparin for the same effect. The study shows how heparin can influence the readiness of sperm for fertilization differently in bulls and stallions.