How hot is too hot?

[Izzyisdizzy11]

Hopefully this link works. It's mostly about raising broilers but most of it should apply to our chickens. The cooling mechanics will be the same.

https://afs.ca.uky.edu/poultry/chapter-7-air-temperature#:~:text=The internal body temperature of birds shows more,have a higher body temperature than larger breeds.

There are different things in there. They talk about food efficiency, in the broiler case converting feed to meat but I'd think it would be the same for converting feed to eggs. The other is the danger of them dying. They gave 95 F (35 C) as when the food efficiency kicks in. I did not see where they mentioned a specific danger temperature for dying other than the ultimate, I think that will vary some per chicken. I'd think the danger is really elevated when the air temperature hits their internal body temperature. That can vary per chicken. In the adult chicken the variability is between 105°F and 107°F (40.6° and 41.7°C). The body temperature of a newly hatched chick is about 103.5°F (39.7°C). I'd start precautions before well before these temperatures.

I lost two chickens to heat. In Arkansas we had a couple of weeks where it was above 110 Fahrenheit (43 C) every day for a couple of weeks. I did not lose them the first few days, there was a cumulative effect. I think there was something wrong with them physically, they were not as robust as the others to start with. Still, it's not a pleasant experience. You don't want to lose any.

A roofed run doesn't necessarily provide shade, especially late afternoon when it's at its hottest. In Australia that would be the north and west sides. I hung a piece of plywood on the west side, that helped. I already had shade other places.

A few of mine would stand in water to cool off, actually a pretty low percentage of them. But, yes, shallow standing water is a good thing to offer. I used a garden hose and wetted down a portion of the run in the shade, that was a real popular area. It was so dry and hot it did not stay wet enough long enough to cause any wet run problems.

Never let them run out of water. Cooler water is better but any water is better than none.

I did not do it and you are dealing with water and electricity so be careful, but look up swamp cooler. That's where you mist water in front of a fan. In hot climates that's a way to keep people cooler, it can work for chickens too.

I don't know what your coop looks like. The more ventilation the better. Since hot air rises openings up high can be really important. I don't know what your nests look like, you don't want them to become ovens. I'd want them pretty well ventilated up high. Nests on the cooler side of the coop, East and for you South, will be cooler than nests on the hot side. You might want to think about shade or insulation if yours are on the hot side but don't block air flow.

Heat is dangerous, I think more dangerous than cold. Sometimes you have to work harder.

Im in Florida, USA - like the others, routine 90s+ at 90% humidity+. Birds can't sweat, so their only defense against heat other than what you might offer them is shade and digging into the soil, which can be considerably cooler than surface temp, even a few inches deep. If the shade is provided by plant life, so much the better - but if not, human structures will suffice.

We have a "heat index" used by the local news media to offer a "feels like" temperature (to humans). Hottest I know this property to hit was 127 heat index. That's dangerous to almost every living warm blooded creature. The storms that followed were "impressive". Just before their arrival was "oppressive" - like trying to exercise in a hot shower. Thankfully, I did not have chickens at the time.

Your bird choices should reflect your climate - you've done well with the ISA Browns - tall single combs, clean legs both help radiate heat.

Thank you

 

[Izzyisdizzy11]

Hopefully this link works. It's mostly about raising broilers but most of it should apply to our chickens. The cooling mechanics will be the same.

https://afs.ca.uky.edu/poultry/chapter-7-air-temperature#:~:text=The internal body temperature of birds shows more,have a higher body temperature than larger breeds.

There are different things in there. They talk about food efficiency, in the broiler case converting feed to meat but I'd think it would be the same for converting feed to eggs. The other is the danger of them dying. They gave 95 F (35 C) as when the food efficiency kicks in. I did not see where they mentioned a specific danger temperature for dying other than the ultimate, I think that will vary some per chicken. I'd think the danger is really elevated when the air temperature hits their internal body temperature. That can vary per chicken. In the adult chicken the variability is between 105°F and 107°F (40.6° and 41.7°C). The body temperature of a newly hatched chick is about 103.5°F (39.7°C). I'd start precautions before well before these temperatures.

I lost two chickens to heat. In Arkansas we had a couple of weeks where it was above 110 Fahrenheit (43 C) every day for a couple of weeks. I did not lose them the first few days, there was a cumulative effect. I think there was something wrong with them physically, they were not as robust as the others to start with. Still, it's not a pleasant experience. You don't want to lose any.

A roofed run doesn't necessarily provide shade, especially late afternoon when it's at its hottest. In Australia that would be the north and west sides. I hung a piece of plywood on the west side, that helped. I already had shade other places.

A few of mine would stand in water to cool off, actually a pretty low percentage of them. But, yes, shallow standing water is a good thing to offer. I used a garden hose and wetted down a portion of the run in the shade, that was a real popular area. It was so dry and hot it did not stay wet enough long enough to cause any wet run problems.

Never let them run out of water. Cooler water is better but any water is better than none.

I did not do it and you are dealing with water and electricity so be careful, but look up swamp cooler. That's where you mist water in front of a fan. In hot climates that's a way to keep people cooler, it can work for chickens too.

I don't know what your coop looks like. The more ventilation the better. Since hot air rises openings up high can be really important. I don't know what your nests look like, you don't want them to become ovens. I'd want them pretty well ventilated up high. Nests on the cooler side of the coop, East and for you South, will be cooler than nests on the hot side. You might want to think about shade or insulation if yours are on the hot side but don't block air flow.

Heat is dangerous, I think more dangerous than cold. Sometimes you have to work harder.

Thanks for all the info! Currently my nesting boxes are on the south side, which is lucky because that was something I hadn't considered before.

 

[Izzyisdizzy11]

Extremely helpful information, @Ridgerunner !

I'd like to add a few, small addendums:



Important point!

I had enough random things in my run last year to provide shade at all times last year, but in the new run I have plans for this summer that include both:

Pallets up on blocks to give overhead shade when the sun is high.

Pallets standing vertically on both north-south and east-west axes to offer shade at all low-sun angles.

The clerestory roof on my coop was specifically designed to capture the breeze that always flows uphill out of the woods when the sun on the clearing where the houses and outbuildings are heats the air up and creates a rising thermal current at the top of the hill.



Minor caveat that this only works when the humidity is relatively low and/or there is a breeze. At 95F with 95% humidity in a dead calm adding mist only makes things more uncomfortable.

We made that mistake with the foggers at the zoo one summer -- coming out of the mist hotter and more miserable than we'd started.



My nests ended up on the west wall, but we designed airflow into them by not bringing the dividers all the way to the wall and not bringing the anti-roost board all the way to the wall. They're internal so when the sun hits the west wall the hot air can rise up and out of the boxes while cool air flows in from the coop interior.

The only disadvantage I've found so far is that chicks of a certain age/size can roost on the dividers or even on the top of the anti-roost board.View attachment 2950630View attachment 2950633View attachment 2950638

Thanks so much for all the info, appreciated

I've considered the mister and our dry climate would make them effective, so I might give them a shot.