Keeping cows fed well, hydrated and in well ventilated housing is essential to overcoming the above consequences of hot weather.
Encourage higher intakes by feeding 60-70% of your herd’s diet between 8pm and 8am, the coolest part of the day. Increasing the energy density of the diet by providing additional concentrate will mitigate drops in intake and help to maintain milk quality. High quality forages will also reduce the amount of heat produced during digestion compared to low quality, stemmy forage. It is essential to ensure that any changes made to the diet do not create an imbalance in the diet – otherwise your herd could develop digestive disorders like acidosis.
Adequate provision of clean, fresh water at all times is absolutely essential to keeping cows hydrated during hot weather and will reduce the risk of acidosis and maintaining feed utilisation. During times of heat stress, cows can drink an extra 100 litres of water per day so be sure to monitor water levels regularly.
Good ventilation in cow housing will keep fresh air coming in and move stale air out, keeping the temperature inside cooler. Research from the United States that air flow as low as 10 kph reduces respiration rates in heat stressed cows by up to 50%! If your cows are normally in paddocks during summer months, consider bringing them inside during the hottest part of the day and ensure that they have access to shade and plenty of water in paddocks.
The most effective way to do this is to install an open or protected ridge in the roof of housing and increase the volume of air inlets. This will bring in more fresh air from beside the building and push old air up and out. Fans are also effective ways of keeping air moving within buildings, especially in high traffic areas like collecting yards.