In cows, the pedometer is mounted around her legs or neck strap to detect a difference in activity from day to day. In herds with electronic feeding and milk weighing systems, the differences in feed intake and milk production can be related to estrus. So are slight increases in body temperature, measured directly in milk at milking time, although on warm summer days the increase in milk temperature usually comes from the sun. Good herds usually do fairly well with any of these gadgets, but marginal herds don't. The next step is to the veterinarian for treatments, not just for his monthly visits of pregnancy checks.
Treatments usually involve reproductive hormones of some kind or related substances.
Then the veterinarian can accelerate the process by administering a series of estrogen and progesterone hormones to bring her into estrus on a certain date. The veterinarian also can inject prostaglandins, which are not hormones but fatty acids. Prostaglandins act on the corpus luteum in the ovaries to bring about estrus within 72 hours. This brings me to the final point. Many good new ideas and solutions in the dairy business have come from New Zealand.