Final steps for winter

When we think about heat stress in cattle or cows, we sometimes think of Mediterranean countries which have to deal with all the associated problems. They have to invest heavily in permanent infrastructure and methods to counteract these events. Here, in this part of the world however, we can usually count on one hand the number of days we hit the 30s in degrees, if at all. Nevertheless, we are now experiencing more extremes in weather. Heat stress is not just about temperature – it also involves humidity. It can be seen from the chart below that even at higher temperatures, it is humidity that can tip the balance of stress for the animal.

The ideal temperature for cattle is between 5 to 15^oC; beyond this, while the cow is still comfortable, they are using energy to control their body temperature. This is where we get into heat stress where the animal struggles to control her body temperature. Heat stress will negatively affect a wide variety of areas, from yield (10-25 per cent), decreased conception rate and immunity, increased risk of mastitis and lameness, as well as poor rumen function.