It is not services per conception. Due to Impaired Reproductive Performance and Culling Caused by Reproductive Health Disorders. All evidence collected to date suggests that maintaining a high level of reproductive efficiency is required if dairy herd profitability is to be maximized. Earlier breeding will improve performance in many herds. Aim for an average of 70-75 days to first service.
Estrous detection is the number one problem.
Little cost is usually involved so it is the most profitable, too. Improvement to this level or above is possible and will be profitable. Because of the many factors that can affect conception rate, making improvements will be more challenging than improving estrous detection in most herds.