Chick body temperature: from hatchery to farm

Upon hatching, the birds are poikilothermic animals: their body temperature will rise or fall depending on the environmental temperature, requiring a metabolic effort by the birds. It will take around 4 days for chicks from adult flocks and 5 to 6 days for birds from young flocks for the thermoregulatory system to behave homeothermically – constant body temperature.

There is a range of body temperature known as the comfort zone, where the birds are comfortable with the temperature surrounding them. The best way to “find” the comfort zone is to measure the birds’ cloacal temperature. The ideal temperature should be between 39.5 – 40.5°C (103 – 105°F) the first three to four days after hatching. However, at 7 days the cloacal temperature tends to exceed 41,1 °C (106°F). If the cloacal temperature is above or below this range, adjustments should be made to the ambient temperature.   The following questions were discussed during the podcast:

• Could you please describe why the thermoregulation process is important for chicks?
• How does thermoregulation occur at the hatch?
• The article mentions that chicks from young broiler breeder flocks need more time to pass from poikilotherms to homeotherms. Why does it happen?
• What is the comfort zone?
• Where and how can we measure the cloacal temperature? And what anatomical differences can we find in chickens exposed to high or low temperatures in the hatcher?
• Are those anatomical differences similar during the first 7 days at the farm?
• What is your recommendation for keeping the ideal chicken temperature at placement and during the first week at the farm?