Heat Stress

Heat stress in dairy cows

Heat stress is a cause for concern for every herd throughout New Zealand, with negative impacts on milk production and animal health. It occurs when temperatures rise above 20C and humidity exceeds 70%, so a large proportion of New Zealand’s dairy cows are at risk from November to March.

Learn more about the symptoms heat stress, or view our video series on YouTube or our Facebook page.

Heat stresses both cow and grass
With two sides to heat stress – the cow affected by the increase in temperature, and the effect the temperature has on the grass – it often occurs when pasture quality drops. When heat stress impacts the cow, it’s impacting the grass as well. (This is also sometimes called rye grass staggers).

Heat-stressed cows experience a decrease in appetite, resulting in a reduction in energy intake. This has negative impacts on milk production, body condition, health, and pregnancy success.

How to reduce heat stress
There are many ways to reduce heat stress, including:

• Water – make sure cows have enough clean water to drink throughout the day. Sprinklers in the yard are also effective at cooling cows as the sun reflects off the concrete, creating increased temperatures quickly. Try running water over the concrete at the same time to cool it.
• Shade can reduce heat stress by 30% to 50%. Cows grouping together in a paddock is a sign they’re looking for shade from one another to cool down. Adding trees or structures in the paddock to provide shade is key to heat reduction.
• Changing feed times – give the best quality feed at night when it’s cooler, and the cow has more energy to eat as much as possible.
• Increase supplementation – increase grains in the shed or energy feeds to ensure every mouthful the cow takes is increasing her energy.
• Mineral supplements – cows receiving the right essential trace minerals are key to dealing with the damaging effects of heat stress.

Agvance manufactures a range of products to combat heat stress. Check these out below and order online today.

Are your cows becoming hot and bothered this summer?

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