Water, shade, and the right nutrition can help mitigate heat stress in cattle.

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.

When temperatures rise

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.
• 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 lighter-colored hides.

Suddenly your herd feels overheated and cattle are less likely to graze.

When grazing stops

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
• 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.

11 hot weather tips for cattle

1. Ensure access to fresh, clean water. A brood cow drinks 25 to 30 gallons of water on a normal day. She’ll drink even more in hot weather.
2. Check water tanks often to make sure they are clean and free of contamination (algae, feces, organic material, etc.). You might need additional portable tanks to ensure adequate access.
3. Place water tanks in shaded areas to keep water cool if possible. Keep waterers several feet away from buildings or fences, so cattle can access water from all sides.
4. Offer supplements to help cows make the most of their forages. Accuration^® Supplements with Intake Modifying Technology^® helps feed necessary rumen microbes to keep cattle eating and encourages snack eating behavior.
5. Choose a mineral designed for consistent consumption during hot weather, like Purina^® Wind and Rain^® Summer Season Mineral.
6. Control flies to prevent further stress and grazing disturbance. Purina^® Wind and Rain^® Fly Control Mineral contains Altosid^® IGR, an insect growth regulator offering a beneficial mode of action to deliver fly control via cattle nutrition. Consider Purina^® Wind and Rain^® Fly Control Mineral to stop the horn fly life cycle by preventing pupae from developing into biting, breeding adult flies.
7. Supply ample shade. Whether it’s provided by trees, a manmade building, or portable structures, shade is critical. It might be necessary to move cattle to a pasture with trees or additional shade.
8. Strategically move rotational grazing herds to fresh pastures in the late afternoon/early evening instead of the morning. Cows will have access to fresh grass when temperatures are beginning to cool and will be more likely to graze.
9. Work cattle as early in the day as possible when temperatures are lower.
10. Don’t graze pastures short before moving cows to another. Pastures with taller, thicker grass feel cooler than pastures with short grass where more soil surface is exposed.
11. Observe cattle frequently and take precautions when hot and humid weather is forecast.

Source:

Chris Forcherio, Ph.D.
Purina/Beef Research Manager

The majority of U.S. cattle producers will wean calves at around 205 days of age 1, or roughly seven months, and typically make the decision on weaning time based on calf age, calf weight, or because ‘it’s what they’ve always done.’

But, there are certain scenarios where weaning calves early makes sense from both a cow and calf health standpoint and from an economic perspective.

There are a variety of economic benefits to implementing early weaning strategies. For the calf, we’re looking at a feeding during a time in their lives when they are extremely efficient at converting feed to gain.

For the cow, we’re able to give her some forage resources that would typically go to the calf, thus allowing her to pick up condition score going into the winter months. Putting on that extra condition means we can save on some winter supplementation by not having to play nutritional catch-up.

Here are three scenarios where implementing early weaning might make sense:

1. Drought or low forage situations
One of the most common reasons for a producer to consider early weaning would be if they’re in a summer drought situation. Considering early weaning in this scenario would save some of your valuable forages for the cow.

Each day an early weaning strategy is implemented saves 10 pounds of forage for the cow. Implementing an early weaning program two to three months earlier than the industry average means that a significant amount of forage could be saved for the cow.

Those extra pounds of forage may go a long way towards increasing the condition score on the cow herd going into the winter months, as cows are likely either late in the second stage of pregnancy or early in the third stage.

Early weaning also means the nutritional requirements of the cow decrease as she no longer needs to put resources towards milk production, allowing her to shift those energy resources to gaining condition.

2. To hit your marketing window
Early weaning may help producers hit a more lucrative calf marketing time, given what the cattle markets are signaling to customers.

There are some scenarios where selling lighter calves means a higher price per hundredweight. There are also scenarios where selling calves earlier than the typical months when calves are marketed (typically mid- to late-fall) means a higher price floor.

If the marketing scenario is right, it’s always good to consider options to capitalize.

3. When stocking density is increased
A reason to wean early that’s becoming more prevalent is land cost, and subsequently increased stocking density. Some cattle producers today are trying to run more cows on the same acreage to potentially increase profit.

More cows on the same acreage mean that the forage resources are limited and that both cows and calves could potentially be shortchanged on nutrients.

If we’re short on forage, either quantity or quality-wise, it’s often a good plan to start calves on a higher plane of nutrition by going ahead and weaning them.

With any of these three scenarios, it’s critical to get early-weaned calves on a quality nutrition program.
These early weaned calves can’t hold a lot of feed because of their small rumen size. At the same time, the calf’s requirements per pound of body weight are quite high. You need a high-quality, nutrient-dense, complete feed to get them off to the best start.

Content source:

NT Cosby, Ph.D.
Field Cattle Consultant
Purina Animal Nutrition