The hidden costs of heat stress can be enormous

Heat stress, a concept we have to deal with more and more days of the year. Heat stress during dry periods affects not only the cow, but also the unborn calf. The calf can suffer the consequences and milk production can be 16% lower than average.  

A relatively short period of heat stress in late pregnancy can dramatically affect the health, growth and eventual performance of dairy calves. It is therefore crucial to effectively manage heat stress in dry cows to avoid negative effects on the calf. Calves are on average three kilograms lighter when they are born and have lower immunity. This is because colostrum contains fewer antibodies, and these are not absorbed as well. For example, calves from cows that have experienced heat stress appear to absorb 43% less antibodies (IgGs) from the same colostrum than calves from cooled cows (Monteiro et al., 2016). 

Milk production is 16% lower

In addition, heat stress on the mother also affects the calf’s weight development. These calves grow an average of 0.2 kg less per day until weaning and are considerably lighter when they leave the milk. The loss at the end of the first lactation is more than twice as high after heat stress in the womb and milk production is 16% lower than average. It has also been shown that calves from a mother not to have experienced heat stress conceive more easily and at a younger age. So, the hidden costs of heat stress can be enormous.

Cow’s appetite drops

Reduced milk yield is the most widely recognised impact of heat stress on a dairy cow. Heat stress during dry-off periods reduces milk production in the next lactation by an average of 4-5 litres. The cow tries to get rid of heat by pumping more blood through the skin. Blood that runs through the skin causes less blood in the udder for milk production and less blood in the organs for energy intake. A cow’s appetite also decreases when it is warm. 

Fatty liver can occur

Due to the lower feed intake, the cow does not get enough energy and protein. To compensate for the protein deficit, the cow breaks down muscle mass, resulting in higher urea levels. The cow compensates the energy deficit by putting less energy into the milk. A prolonged drop in milk production due to heat stress can result in a fatty liver, because the energy that would normally go towards milk production is now spent on producing fat – an inefficient process. Something you do not want as a dairy farmer! 

The AHV Booster Tablet will compensate for the energy deficit by activating the cow’s metabolism (liver and rumen). It will help the liver to convert fat into energy more efficiently. Would you like to know more about the AHV Booster Tablet? Click here and read more or contact a specialist directly!