Customer Resources aAa® Use Made Simple Organize your cows and bulls into simple breeding groups. Available as a downloadable spreadsheet or printable pdf. aAa Use Made Simple aAa Use Made Simple Printable Weeks Use Made Simple Use Made Simple Instructions Bull Central Searchable online database containing aAa numbers for over 70,000 bulls worldwide. Find the perfect match for your cows. Bull Central Instructions Perfect Match Online tool that lets you upload cows, select bulls, choose the best aAa match, and save or print a breeding list. Perfect Match Instructions For questions or assistance with using any of the above services, contact your analyzer or the aAa® office.