Keep your birds cool and avoid heat stress.
By Heather Levin. Here in Tennessee, summer starts in early May
and often only ends in November. It’s not just hot here. It’s like living in someone’s mouth…with high temperatures and humidity the norm for much of the year. Keeping my herd cool during our endless summers sometimes feels like a full-time job.
Many chicken farmers don’t realize that chickens have a harder time staying cool than staying warm. A chicken’s body temperature ranges from 105 to 107 degrees Fahrenheit, and roosters tend to have a slightly higher body temperature than hens.
Once the temperature reaches 85 degrees F, the chickens change their behavior to stay cool. You will see this change in behavior as it moves its wings away from its body, restricts its activity to shady areas, eats less, and pant more.
Heat Stress Hazards
Exposure to prolonged episodes of hot temperatures, especially when humidity
is thrown into the mix, can cause heat stress in chickens. Broilers are particularly exposed to heat stress due to their high metabolism.
Heat stress can lead to a drop in egg production. It can also damage organs
and affect the cardiovascular system. Over time, heat stress can affect the
immune system, which puts birds at increased risk of bacterial, viral and parasitic infections. Fortunately, there are many natural herbs and strategies we can use to help keep our birds cool during the summer.
Naturally refreshing herbs
A 2016 study in Iranian Journal of Applied Animal SciencesI found that
broilers given dried peppermint powder during periods of heat stress had lower body temperatures than the control group.
I grow a lot of peppermint on our property for this reason. One of
the best way to give your chickens the benefits of peppermint is to put it fresh in their water every day. Peppermint gives the water a refreshing taste and your chickens will drink more when in it.
There are several other cooling herbs you can put in your chicken.
water daily, including lemon balm, borage and holy basil (tulsi). You can also make a tea with these herbs and once completely cooled you can offer it to your chickens instead of water.
Lemon verbena, vitamin C and turmeric
A 2016 study in The Journal of Animal Physiology and Animal Nutrition found that adding lemon verbena and vitamin C powder to chicken feed suppressed the negative effects of heat stress.
Lemon verbena is a delicious herb to grow at home, and it makes a delicious tea for you or your birds. You can mix fresh or dried lemon
verbena in your chickens’ feed or put fresh lemon verbena in their daily water. The Poultry DVM recommends giving 200mg to 500mg of vitamin C powder daily to laying hens experiencing heat stress.
A 2015 study in Health and production of tropical animals found that dried turmeric helped improve stress tolerance and immune response in
heat-stressed chickens. Another study, published in 2021 in Veterinarian and
animal sciencediscovered that turmeric not only prevented and reduced stress
but also reduced inflammation and stimulated growth performance in
You can harness the anti-inflammatory benefits of turmeric by sprinkling 250mg per bird in food or water, especially on hot summer days.
Keep in mind that in hot weather most chickens will eat less and drink more. That’s why supplementing herbs and vitamins in water, rather than mixed with feed, can help ensure that your chickens get enough of them to feel the benefits.
Lots of fresh water
Chickens that do not have access to fresh water will die quickly from the heat.
So make sure your birds always have plenty of fresh, clean water to drink. Remember that water evaporates quickly in hot weather and your
chickens will drink more, so check water levels throughout the day.
During the summer months I have brought out several extra 5 gallon buckets modified with poultry nipples for my flock just to make sure they don’t leak
out. I keep them in shaded areas, where the hens naturally like to rest,
so they don’t have to walk far to fetch water.
If you already put fresh peppermint in your chicken’s water, add ice or a bottle of frozen water. Drinking cold peppermint water will help lower your chicken’s body temperature and encourage it to stay hydrated.
Consider late feeding
Digestion of food raises body temperature, so feeding your birds later in the day can help keep them cool. During the summer, I usually feed my free range herd around 5:00 p.m.
If you want to give treats during the day, choose hydrating and healthy foods like fresh watermelon, cucumber, or grapes. You may also consider replacing hens with starter feeds, which have a higher protein content, and providing oyster shells ad libitum to meet their calcium needs. Because many chickens eat less during heat, switching to a starter feed can help ensure they get the protein they need even when eating less.
Think how refreshing it is to enjoy a bowl of ice cream on a hot summer day. Well, your chickens feel the same way when you feed them healthy frozen treats like frozen bananas, grapes, blueberries, sugar snap peas, and other mixed vegetables. It helps keep them cool and it’s a refreshing snack on a sweltering day.
Another option is to take fresh fruits and vegetables and pour them into a Bundt pan. Fill the Bundt pan with water and freeze it. When it’s completely frozen, set it outside for your chickens to peck on.
You can also pour low-sodium canned vegetables into muffin tins and
freeze for an easy treat.
A little nuance to them
If your hens are confined to a run during the day, make sure they have a shady place to stand no matter what time of day. And make sure the size of the shaded area is large enough to accommodate your entire herd.
You can add shade to your run with tarps, curtains, tin roof, shade sail,
or pruned tree branches. You can also create shade by planting trees, tall grass or bushes along the outside of the enclosure. Whatever strategies you decide to use to keep your chickens cool, they will appreciate it. After all, your hens wear a down coat on the hottest summer days, so
making sure they have cool water to drink, frozen treats and plenty of shade will definitely make a difference!
HEATHER LEVIN is a farmer, chicken trainer of over 30 chickens and the founder of The Greenest Acre and Chicken Health Academy, a pioneering online learning academy that teaches natural and emergency care strategies for chickens. Get weekly chicken care tips via her website: The
• Backyard Poultry Medicine and Surgery, Second Edition
copy), (p. 47, on chicken body temperature)
• “Efficacy of peppermint powder on performance” S. Arab Ameri,
F. Samadi, Iranian Journal of Applied Animal Science, 6:4, December 2016,
pages 943-950. https://ijas.rasht.iau.ir/article_526645.html
• “Effect of the power of lemon verbena on performance and immunity
heat-stressed broilers. F. Rafiee, M. Mazhari, Journal of Animal
Animal Physiology and Nutrition, 100:5, October 2016, pages 807-812.
• “Alleviation of chronic heat stress in broiler chickens by supplementation
betaine and turmeric”, Hossein Akhavan-Salamat, Tropical Animal
Health and production, 48, 2016, pages 181-188. https://link.springer.
• “Effects of dietary turmeric in broiler chickens”, Meysam Khodadadi,
Veterinary Animal Science, December 14, 2021. https://www.ncbi.nlm.nih.
Originally published in the June/July 2023 issue of Backyard poultry magazine, and regularly checked for accuracy.