There are so many benefits of using AI. You use semen from the best bulls in the world. Your replacements will give more milk. have better fertility and easier calvings. You can used sexed semen increasing the number of heifer calves born to 90%. AI bulls and straws are tested so you know the semen is fertile and free from disease. You choose the breed and bull you want. There are no upkeep costs or dangers from having your own bull, or risk of injury to people, your animals or property. Using AI makes sense. Some bulls used for natural service have poor fertiltiy, carry disease which is spread from cow to cow and they may produce big calves that have difficult calving. There is always a risk of injury to cows and people with bulls. AI is much better for breeding compared to natural service.