By: Andi Mushawwir

The rise in global temperatures is no longer merely an environmental issue discussed at climate change conferences. Its impacts are increasingly being felt in production environments, including poultry houses. For the poultry industry, particularly in tropical countries such as Indonesia, rising ambient temperatures do more than simply cause chickens to pant during the day. Heat stress can compromise animal welfare, suppress productivity, and increase the risk of economic losses.

Poultry are highly sensitive to changes in temperature. Chickens do not have effective sweat glands to dissipate body heat. Their bodies are also covered with feathers, while their high metabolic activity continuously generates internal heat. This condition is particularly relevant to modern broilers. Genetic selection has produced chickens with very rapid growth and high feed efficiency, but these productive capabilities are also accompanied by greater metabolic heat production.

Therefore, the future challenge for the poultry industry is not merely how to maintain production as ambient temperatures rise. The more important question is how to maintain performance without subjecting chickens to excessive heat loads.

Welfare and Productivity Begin with the Chicken’s Ability to Cope with Heat

Understanding of animal welfare is no longer limited to ensuring that chickens have access to feed and drinking water and are free from disease. The World Organisation for Animal Health (WOAH) defines animal welfare in terms of an animal’s physical and mental state in relation to the conditions in which it lives and dies. The concept of the Five Freedoms also encompasses freedom from hunger and thirst, fear and distress, physical and thermal discomfort, pain and disease, as well as the ability to express normal behavior.

In the context of climate change, freedom from thermal discomfort has become particularly important. Poultry house temperature is not merely a figure on a control system, but part of the conditions that determine chicken welfare. Under hot conditions, chickens attempt to maintain a balance between the heat generated by their bodies and the heat that can be released into the environment. As long as this mechanism continues to function effectively, body temperature can be maintained. Problems arise when environmental heat and metabolic heat exceed the chicken’s ability to dissipate heat. This condition is known as heat stress.

The early signs can be observed directly. Chickens reduce their activity, hold their wings away from their bodies, increase water consumption, and begin panting, or rapid open-mouth breathing. Panting is an important mechanism for dissipating heat because chickens cannot sweat effectively. However, when it continues for an extended period, this mechanism increases carbon dioxide loss and can disrupt the body’s acid-base balance.

Chickens will also reduce their feed intake. Physiologically, this helps reduce metabolic heat production because the digestion and metabolism of nutrients generate heat. For farmers, however, reduced feed intake means lower energy and protein intake, slower growth, and decreased production efficiency.

In laying hens, prolonged heat stress can reduce both egg production and egg quality. In broilers, its effects may be seen in growth, feed efficiency, meat quality, gastrointestinal health, and increased mortality. In other words, chickens maintain essential bodily functions at the expense of part of their production potential.

The effects of heat stress also extend beyond behavioral changes. An increase in body temperature triggers changes in the endocrine system, metabolism, blood circulation, immune system, and oxidative status. The production of heat shock proteins increases as part of the cellular defense mechanism. At the same time, the formation of reactive oxygen species can increase and trigger oxidative stress when it is not adequately counterbalanced by the body’s antioxidant system.

This article is an excerpt from the Opinion section of the September 2026 edition of Poultry Indonesia magazine. Read the full article in the September 2026 edition of Poultry Indonesia magazine. For subscriptions or further information, contact us via WhatsApp or email sirkulasipoultry@gmail.com.

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