Mary Allen
Chickens are considered cold-resistant animals. However, they can still catch colds and frostbite if their barn is poorly ventilated and the bedding is not changed enough. Moisture is more of a problem for them than sub-zero temperatures.
Cold, snow, and few food options cause birds to migrate south during the winter months. However, not all birds can escape the cold weather conditions. Chickens, with their poor ability to fly and often a captive life, are forced to remain in their homes during the winter.
However, most breeds of chickens have managed to adapt to cold climates during their domestication. In general, chickens tolerate the cold better than the heat. But not all breeds are equally suitable for winter. For example, the Appenzell bearded chicken was bred to be particularly cold-resistant for the Alpine region, the Rhineland chicken for the Eifel mountain region, or the Chanteceler chicken for the frosty regions of Canada.
Receptors in the Skin Monitor Temperature
Chickens are very good at sensing environmental temperatures. According to Carl Engelmann, former head of department at the German Institute for Agricultural Experiments and Research, little is known about the sensory organs in poultry. However, some assumptions have been made from observations in humans.
It is assumed that the free nerve endings, which are surrounded by thin layers of connective tissue – the so-called «Krause end bulbs» – are the organs that receive cold stimuli. Opposite them are the «Ruffinian balls», the receiving organs for heat stimuli. Both organs are distributed throughout the body. When drinking, the chicken reacts to heat stimuli with astonishing certainty and sensitivity. The animals are insensitive to indifferent to cold stimuli. Therefore, it is believed that there are more heat spots near the beak.
However, chickens also have a comparatively high body temperature. It is between 39 and 44 degrees and is thus a lot higher than that of mammals. Chickens feel most comfortable when the outside temperature is between 17 and 28 degrees. Then the body temperature of the chicken remains constant. Higher or lower ambient temperatures usually lead to changes in body temperature. Other factors can be breed, age, laying performance, or exercise intensity. Daily metabolism also influences body temperature. It usually peaks around 4 pm and then steadily decreases until it bottoms out at midnight.
In controversial experiments in the 1960s, it was found that when the outside temperature is below 17 degrees, the starving chicken tries to maintain its body temperature with physiological changes: by constricting the blood vessels on the body surface, by increasing the metabolism, changing the hormone balance or by muscle tremors. The chickens even withstood minus 50 degrees without their body temperature dropping dangerously. Geese even endured minus 90 degrees, ducks minus 100.
Closed Windows are Well-Intentioned, but Increase Humidity
But even if chickens are very cold-resistant, they are not immune to colds. In most cases, however, the trigger is not to be found in the low temperatures, but in the chicken housing. If the litter in the barn is always damp, the chickens’ feathers will soon be wet too. It is therefore important to use absorbent bedding such as wood shavings. Another variant is a canopy at the chicken door. As a result, less moisture is channeled into the stable.
Poultry farmers often close the windows of the chicken house in winter so that the animals do not freeze. Because the cold air absorbs less moisture, the exact opposite is achieved. The moisture settles on the litter and the animals themselves. If there is also a draft, the typical cold symptoms set in relatively quickly. In addition to a wet nose, you can recognize the cold from the heavy breathing of the animals.
Animals with a cold should be immediately isolated from the rest until they have recovered. Drugs or vaccinations are not common in hobby breeding, in contrast to commercial poultry farming. The breeder can prevent a cold by changing the litter more often during the cold season.
Laying Activity Only Decreases at Extreme Temperatures
The winter months mean more work and less pay for the breeder. Because in the winter months, chickens lay fewer or no eggs at all. The lack of laying activity is due to several factors. Researchers do not agree on the weighting of the individual points. The environment plays a role on the one hand, but also the duration of daylight on the other, and last but not least the hereditary factor should also be decisive.
In an article by the “Agricultural Research Service” from the United States, the best laying temperature was recorded as 13 degrees on the basis of intensive studies. The hens laid the most eggs and at the same time consumed the least feed. However, the study also showed that laying activity only fell by five to ten percent when the temperature remained constant within a range of four to 24 degrees. At minus five degrees, however, activity fell to 26 percent.
This shows that the laying activity is influenced by the outside temperature, but only decreases drastically at extreme temperatures. The investigation also found that the eggs grew larger as the temperature dropped and had a harder shell. In an experiment in which the chicken coop was open to one side throughout the winter, it was found that laying activity decreased, but the hens caught up again in the warm seasons. In addition, they suffered no damage to their health. Only the feed consumption was slightly increased.