Cooling your cows this summer

Now that the weather is warming up, it is a good time to think about what you can do to minimise heat stress in your herd.

The consequences of heat stressed cows are well known - decreased milk production, reduced feed intake, potential loss of body condition, mastitis, potential to not conceive or to abort, and other animal health related symptoms. Now is a good time to step back and review one of the biggest risks to milk production.

There are short and long term risk management practices that can be implemented to reduce the impact of hot weather. The Cool Cows program developed by Dairy Australia offers a suite of resources, guiding you to areas of your farm which can benefit from some simple actions providing big benefits.

On the Cool Cows website, you can subscribe to a free alert service which will notify you of upcoming severe heat stress events. Of course if you sign up for this service, you will need to have a plan for how you will tackle heat stress events.

If you know the day is going to be high risk for heat stress, you can plan to change your daily routine. By minimising the time your cows spend walking and on yards during the hottest part of the day can reduce heat stress.

Milking and feeding your cows before 10am, and delaying afternoon milking until after 5pm, can make a big difference. Consider how far your cows need to walk in the hottest part of the day (about 3pm) and on extreme days, avoid walking the cows to the dairy until after 4pm. You may consider changing your paddock rotation based upon which paddock provides the greatest amount of shade, a sacrifice paddock or a cool stand-off area.


Importantly these areas need to have ready access to clean drinking water.

Sprinklers are an easy option that provide a huge benefit in cooling cows. Ideally have sprinklers operating on an on/off 15 minute cycle with 1-3 minutes on and 12 minutes off. This allows enough time for cows to be wet to the point that excess water does not drip down the udders, as it is important to not increase the risk of mastitis. Minimising sprinkler on time reduces the water contributing to the effluent stream. If you do not have sprinklers then an alternative is hosing down the yard before bringing in the cows, as this will cool down the concrete surface. In combination with sprinklers, fans and ventilation systems in the dairy also keep cows cool.

During extreme hot weather, a cow will reduce her feed intake and try to consume most of her feed in cooler parts of the day/night. This can compromise rumen function, causing a wider variation in rumen pH and a greater risk of ruminal acidosis. A diet that combines high quality fibre with increased energy and a high rate of buffers can help minimise these effects.

For high producing herds, it is even more important to manage the diet and it would be worth discussing with your nutritionist. Think about diet options such as slowly fermentable sources of starch, feeding partial-mixed rations and fat supplementation.

During the cooler times of the year, some longer term solutions can be implemented to manage heat stress. Longer term solutions vary for each farm but focus on installing more water troughs and increasing shade. This includes shade cloth over the dairy yard or a roof over the feed pad.

For the longer term you could plant more trees across the farm to provide shade and protection from the weather. Also ensure you have adequate water flow to troughs that will cope with peak demand in hot weather, particularly if you have recently expanded your herd.

For more information, visit the Cool Cows website to see what strategies you can implement to manage heat stress in your herd. Alternatively contact Ashleigh Michael DEPI Leongatha on 03 5662 9901.

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