This article was written by Angie Wilson (Dairy Specialist, OMAFA). This article was originally published in the Spring 2026 issue of the Dairy Goat Digest.
Introduction
While goats generally tolerate heat better than other livestock species, they are still susceptible to heat stress. Heat stress has immediate and long-term negative effects on goat production and health. For example, individual studies have reported that heat stress in dairy goats is associated with approximately a 29% reduction in feed intake, a 10% reduction in milk production and a 14% decrease in milk protein (Salama et al., 2021).
What Causes Heat Stress?
Heat stress occurs when environmental conditions become too hot for goats to dissipate heat, and they can no longer regulate their body temperature. Heat generated internally from normal metabolic processes, combined with external heat from the environment, overwhelms the goat’s ability to cool itself.
Humidity in the air worsens the negative effects of heat by reducing evaporative heat loss. As humidity increases, cooling via respiration and sweating becomes less effective. High temperatures are often accompanied by elevated humidity, which makes coping with heat more challenging.
Around 24°C, adult goats approach the upper limit of their thermoneutral zone and may start experiencing heat stress. However, the presence of high humidity conditions, intense sun exposure, and limited air flow can result in heat stress occurring at lower air temperatures. Susceptibility to heat stress is also affected by life stage, production level, genetics, and nutritional status. Higher-producing animals generally have lower tolerance to heat stress as they have a faster metabolic rate and generate more heat from their increased productivity.
Effects of Heat Stress:
- Decreased milk production and protein
- Reduced growth and/or weight loss
- Weakened immune function, making your herd more susceptible to getting sick
- Reproductive challenges
- Death
Recognize the Signs of Heat Stress
Know the signs so you can catch heat stress early:
- Rapid breathing, shallow breathing, panting, open-mouth breathing
- Standing up (less time lying down)
- Seeking areas with better air movement
- Reduced dry matter intake
- Increased water intake
- Crowding around a water source
- Seeking shade
Signs of severe heat stress include open mouth breathing with neck extended and tongue out, drooling, staggering and/or inability to stand.
Practical Strategies to Mitigate Heat Stress
Alleviating heat stress through the following housing and management strategies can help minimize production losses due to heat stress.
| Prevention Strategy | Why it Works |
| Increase airflow to where goats are (at their level), open curtains, use fans. Airflow of at least 1 m/s is recommended | Greater body surface area exposed and faster air movement increase heat loss |
| Avoid overcrowding and ensure there is enough space for all goats to access air flow | Crowding raises the temperature and humidity, making it harder for them to cool down. Goats need to have enough space to dissipate heat, and to access water and air flow |
| Give unlimited access to cool, clean water. More water provided more often may be necessary | Cool water helps lower body temperature and replenishes water loss from panting and sweating |
| Feed a nutrient-dense feed and feed early in the morning or later in the evening | Digestion generates heat, so feeding during cooler times of the day reduces the amount of additional heat added to the goat’s body |
| Avoid handling, animal work or other stressful events (e.g., transport) during the hottest parts of the day | Stress generates additional body heat, adding to their already elevated heat load |
| If goats are outside, provide shade (artificial and/or natural) | Shade removes the significant heat load from direct sunlight |
| Nighttime: keep curtains open and fans on at night | Barns retain heat from the day. Cooler temperatures at night can help goats recover from daytime heat |
| Monitor the weather forecast and apply prevention strategies proactively | Adverse effects are already happening by the time signs of heat stress are visible. Act before your goats are compromised |
A note on airflow: Air movement needs to be at the goats’ level, not yours. Just because it feels cool at your height or when standing in the feed alley, does not mean the air is moving where it really matters – down where the goats are.
Considerations for Other Groups
Late-gestation does, high-producing does, young kids and bucks all face unique susceptibilities and require extra attention during periods of heat stress. Identify these animals in your herd and ensure they also have access to cooling resources.
Your dairy goats’ performance and health are adversely affected by heat stress. Being able to recognize and mitigate heat stress can help minimize production losses.
Sources and Resources:
Gupta, M., & Mondal, T. (2021). Heat stress and thermoregulatory responses of goats: a review. Biological Rhythm Research, 52(3), 407–433.
Metzger, M. (2020, June 23). Avoid Heat Stress in Your Sheep and Goats. The Ohio State University.
Most, M., Gibbs, R., & Yates, D. (2023, December 1). Managing Sheep and Goats for Heat Stress. Nebraska Extension.
Salama, A.A.K, Hamzauoui, S., Albanell, E., Such, X., & Caja, G. (2021). Metabolic and behavior responses of lactating goats under heat stress. Small Ruminant Research, 203, 106496.
