HOT WEATHER does not come without its drawbacks and even at just 20°C, heat stress can reduce feed intake, drop butterfats and cut milk yields by up to 20%.
KW’s nutritionist, Dr Anna Sutcliffe, in a timely statement this week, said: “When cows are in direct sunlight or high humidity, even modest ambient temperatures will cause milking and transition cows to start suffering the negative effects of heat stress.
“Watch closely for cows that are panting, lethargic, standing rather than lying or with a respiratory rate higher than the normal 26-50 breaths per minute. 
“Reductions in feed intake or milk yield of 10% or more – as well as increased ration sorting – can also indicate that heat stress is a problem.”
Good access to clean drinking water is essential, as are changes to herd management to reduce exposure to direct sunlight – things like lower stocking rates, better ventilation and increase access to shade help, too.
Rations should be adjusted to account for lower feed intakes. 
“Increase ration energy density by feeding high quality forage – or using energy-rich moist feeds like Traffordgold – and boost digestible fibre intakes to reduce acidosis risk by including sugar beet feed, British wheat distillers’ feed or soya hulls,” said Dr Sutcliffe.