HERD HEALTH CHECK CURBING HEAT STRESS
WATER, SHADE AND THE RIGHT NUTRITION CAN HELP MITIGATE HEAT STRESS IN CATTLE from Purina Animal Health The weather report says it’s going to be a scorcher, and sure enough – the temperatures start steadily climbing. Cattle start grouping in shady spots. A few cows start panting to stay cool. The flies settle in. And, suddenly, you’ve got a herd struggling with heat stress. The heat may be unavoidable, but you can take proactive steps to mitigate its impact on your herd. First, let’s look at the dangers of heat stress in cattle.
• Crowded cattle attract more flies, causing animals to move even closer together to protect themselves. • Animals with dark hides have a higher risk of suffering heat stress than those with lightercolored hides. • Suddenly your herd feels overheated and cattle are less likely to graze.
WHEN TEMPERATURES RISE
Forage is the number one nutrition source for cows on pasture. If they aren’t grazing as much during a heatwave, they’re probably not meeting their cattle nutrition requirements. When cows don’t get adequate nutrition, they’re at risk of: • Losing body condition • Taking longer to rebreed • Producing less milk for their growing calf • Generating a weaker immune response to health challenges
Cattle have sweat glands, but it’s not a very efficient way for them to cool off. Instead, they rely on respiration, or opening their mouths and panting, to help them dissipate heat. When it’s 80 degrees or hotter out, their ability to regulate their own temperature becomes a big challenge. You start to see behavior changes – more time in the shade, less time grazing and increased water consumption. To make the heat even more challenging: • A cow’s rumen activity naturally increases body heat. Fermentation occurs in the rumen, producing heat as bacteria break down and digest forages. • Cattle seek shade to help keep cool. Grouping up in the shade sometimes has the reverse effect and creates a lot of radiant heat between cows. • The thermometer might read 90 degrees, but the temperature in the middle of the group could be much hotter.
24 California Cattleman July 2024
WHEN GRAZING STOPS
LONG-TERM FERTILITY CONSEQUENCES If cattle are too hot to graze, they may also be too hot to consume mineral at target intake levels. If you’re using a fly control mineral and intakes are below target levels, cows no longer benefit from it because they aren’t getting a full dose of fly control. Curb heat stress in cattle by planning for proper shade, water and the right nutrition program