Bird Response to Hot Weather

If the temperature in your barn is 26 C or less, it is very unlikely that the birds will experience heat stress no matter what the humidity or airspeed. At moderate temperatures, the birds can easily lose the large amount of heat that they produce as they digest their food, produce eggs and meat, and move about the barn. As the temperature rises above 26 C, the birds must adapt to prevent an excessive build up of this heat inside their bodies. The first response is for the birds to spread their wings, start irregular panting, and reduce feed intake. They use these strategies to lose more body heat and reduce the amount of heat that they are producing internally. As air temperature continues to rise, their body temperature will increase and the birds will begin very rapid panting. If the heat stress continues too long and the birds’ body temperature increases by 4 C to 5 C, death will occur. It is the inability to lose body heat quickly enough and the rise in body temperature that kills the birds. In moderate climates such as Manitoba, it is not mortality but the smaller egg size and slower growth rate as the birds back off feed that cause the major economic losses due to hot weather.