Tackling Heat Stress in Dairy Cows

As we are coming into our British summer, now is the time to start thinking about heat stress.  Cows start suffering with mild signs from air temperatures of 21 degrees Celsius (70 degrees Fahrenheit), therefore it’s worth taking some precautions.  The impact on reduced milk yield alone will affect the farm business and the animal’s welfare.

The above table gives you an indication of that impact, as you can see even at 22 degrees, 50% humidity with 4 hours a day exposure, she can lose one KG (kilogram) of milk production – 200 milking cows = 200 litres at 29 pence per litre which is a loss of £58/day.  This loss more than doubles with a three degree increase in temperature.

So…. ‘’What can we do to reduce heat stress?’’

• Observe for signs, cows will pant with mild over heating to blowing – tongues out, drooling saliva in more severe temperatures.  It is important for you and your staff to monitor cow’s behaviour when grazing during the day and at milking times.
• Keep activities to a minimum, don’t push the cows and over crowd, the obvious area is a holding pen or the collecting yard, keep cow population light in these areas.
• Select fields with shade if possible.
• Keep cows in during the day and graze at night.
• Make sure there is plenty of clean water available, one animal will drink 15 litres per hour, so she needs stress free access to water supplies.  Troughs need to have the capacity to allow 20 cows to drink simultaneously without competition from other herd mates
• If barn fans are in place, make sure they are clean and have been maintained.
• Set up a sprinkling system in the collecting yard to soak the cows to the skin, this will help reduce and control core body temperatures – especially in conjunction with fan cooling.
Heat stress will also influence fertility (silent heats), feet problems as they stand for longer to aid cooling and reduce appetite.  Think cow comfort and welfare, minimise their discomfort – they pay your wages!

Contact Mark at markyearsley@fcgagric.com or your local FCG office, to have an independent look at your cow behaviour and ensure that they are working as efficiently as possible under the minimum stress.

Posted in Business Management, Dairy & Forage, Sherborne.