Avoid heat stress to boost fertility

Avoid heat stress to boost fertility

Putting in place steps to prevent heat stress is necessary in order to maximise herd fertility.

A recent paper reviewing the effect of heat stress on dairy cows looked at 15 dairy farms in Germany. It showed as temperature and humidity index (THI) increased, the number of cows inseminated decreased and the number of successful inseminations went down from 38% to 18% on the hottest days.

Other health traits such as mastitis, retained placenta and post-calving metritis also got more common as the THI increased. In fact, the only health event that improved was digital dermatitis; presumably due to drier under-foot conditions.

There are many days in the summer where heat stress will affect cows (see chart). Having a prevention strategy in place will minimise losses.

Heat stress prevention can range from:

  • Cooling the air with air movement
  • Providing plenty of water drinking stations
  • Feeding and moving animals at cooler times of the day
  • Providing plenty of shade outside.

Supporting follicle development in the cow using antioxidants over the 100 days of transition to insemination can help minimise the effects of heat stress on fertility. To get the best from these products, they need to be fed over the heat stress period to make sure the balance of oxidants and antioxidants are maintained.

Fertility-Link 365

In a recent survey, Mole Valley Farmers asked 294 dairy farmers some key questions about cow fertility management. As part of a new ‘Fertility Link 365’ series, the Mole Valley Farmers’ team will highlight some of the key themes from the survey and offer advice on boosting fertility on farm.

For more information on keeping cows cool and maintaining good fertility during the summer, please speak to your local vet or nutritionist.