Events and time intervals associated with standing heat and timing of service are summarized in Figure 2. It is recommended that cows be bred 12 hours after standing heat is first noticed. Management suggestions 1. Cows in conventional housing systems should be turned out twice daily for 20 to 30 minutes, once in the morning and again in the evening. Loose housing systems do not make heat detection easier.
Check cows for signs of heat at least three times a day, more frequently if possible.
These times should be morning, early afternoon, and late in the evening. Schedule these observation periods so as to avoid feeding times and those times when cattle are moving to and from milking. Remember that most mounting occurs between 6 p.m. and 6 a.m. and that 25 percent of the cows are in heat less than eight hours. Use your time efficiently and check heat during times when cattle are most likely to express heat. Slippery and muddy conditions may severely inhibit mounting activity.