The second problem shows up as a low conception rate or high services per conception. Anestrus Cows may not be detected in estrus due to failure of ovarian function and absence of estrus. More commonly, the frequency of mounting in hot weather is reduced and a producer misses seeing the few mounts which do occur. Some dairy producers may have both problems. The underlying cause of improperly functioning ovaries is thought to be only an indirect effect of high temperatures.
Cows eat less feed during hot weather.
Any producer who thinks this might be the problem should look at the records from the veterinarian's palpation of the cow's ovaries. Cows that calve immediately before or during hot weather are most likely to be affected. Check the records for each cow not observed in estrus. It is important to look at results of the veterinarian,s 30 to 75 day postpartum palpation record for each cow. Scientists in Florida recommend increasing the energy concentration of the cow's feed to account for reduced intake during hot weather.