Final answer:
Dairy cows should be pregnancy checked 90 days after breeding to determine if they are pregnant and make appropriate management decisions.
Step-by-step explanation:
Dairy cows should normally be pregnancy checked 90 days after breeding. Pregnancy in animals varies in length, with cows having a gestation period of around 9 months. By checking for pregnancy 90 days after breeding, farmers can determine if a cow is pregnant or not and make appropriate management decisions. This allows them to optimize their breeding program and ensure the health and productivity of their herd.