How temperature and humidity affect cattle feed intake

Introduction

The relationship between temperature, humidity, and cattle feed intake is a critical theme in animal nutrition and environmental physiology. This assumes particular importance today, as many regions are facing drastic changes in climate events, namely extended heat/cold waves.

In this article, we will be looking at the effects of both temperature and humidity on feed intake in cattle.

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What is the thermoneutral zone in cattle, and why does it matter for feed intake?

Cattle are homeothermic animals, meaning they rely on complex physiological mechanisms to maintain a stable internal temperature, which are influenced by environmental conditions, namely temperature and humidity.

Thermal stress occurs when the animal's thermolysis mechanisms are not sufficient to regulate its body temperature. When environmental conditions such as high temperature and humidity exceed the animal's thermoneutral zone, heat stress occurs—leading to decreased feed intake, altered metabolism, and compromised productivity. Conversely, cold temperatures can increase intake to support thermogenesis. Understanding how these climatic factors influence feeding behaviour is essential for optimizing livestock performance, welfare, and resource efficiency under diverse environmental conditions.

How does heat stress affect feed intake in cattle?

Heat stress is a problem that affects cattle around the world. The Temperature-Humidity Index - THI is a practical tool that correlates temperature and relative humidity, and it helps to provide information of possible heat stress conditions to cows.

When temperature and relative humidity rise beyond the thermoneutral zone, cattle experience heat stress, leading to a physiological response aimed at minimizing internal heat production. One of the primary adaptations of this mechanism is a reduction in feed intake, as digestion—particularly of fibrous feeds—produces metabolic heat (heat increment). This decline in intake helps lower heat load. High humidity adds up by limiting evaporative cooling (e.g., panting and sweating), making cattle more susceptible to thermal strain even at moderate temperatures. Together, elevated temperature and humidity—quantified using the Temperature-Humidity Index (THI)—can significantly reduce feed intake (intake may drop by 10-30% at THI>75), compromise welfare, productivity, and necessitate climate-adaptive management strategies in cattle operations.

What happens to cattle feed intake under cold stress?

Cold stress in cattle typically leads to an increase in voluntary feed intake as animals attempt to generate additional metabolic heat to maintain core body temperature. When ambient temperatures fall below the lower critical temperature of the thermoneutral zone, cattle experience increased energy demands for thermoregulation. This stimulates an increase in feed consumption, particularly of high-energy feeds, to support heat production through digestion and metabolism. High fibre diets are also beneficial due to fermentation heat. However, if the feed offered is of low quality or limited availability, the animal may fail to meet its energy requirements, resulting in body condition loss, weakened immunity, and reduced productivity. Young calves, thin animals, and those exposed to wind and moisture without shelter are especially vulnerable. Effective cold stress management includes ensuring increased feed energy density, providing windbreaks or shelters, and access to dry bedding to support both intake and energy conservation during cold periods.

Mitigation and adaptive strategies 

Mitigating thermal stress, ensuring good welfare conditions, and preserving cattle feed intake requires a combination of environmental, nutritional, and management strategies, that need to be adapted to either hot or cold environments. 

Besides environmental measures (installations, cooling systems, etc…) feeding practices can also be adjusted by offering high-energy, low-heat increment rations and scheduling feeding during cooler parts of the day (early morning or evening).

In cold conditions, energy-dense diets (high digestibility fibre ensuring necessary nutrient intake) and windbreaks or shelter are essential to support increased feed intake and maintain body temperature. 

Overall, integrating climate-adaptive feeding systems with precision management ensures animal welfare, sustained productivity, and resilience against climate variability.

Take home messages

Temperature and humidity play a pivotal role in regulating feed intake in cattle, influencing both their physiology and productivity. 

• Elevated temperatures combined with high humidity levels induce heat stress, which suppresses voluntary feed intake as cattle attempt to reduce metabolic heat production.
• Conversely, cold stress typically stimulates increased intake to meet the energy demands of thermoregulation. 

Both extremes, if not properly managed, can impair growth, reproduction, and milk yield. Effective mitigation requires an integration of environmental controls, strategic feeding schedules, and nutritional support. 

Understanding the physiological mechanisms that lay behind thermal stress responses will allow a better prevention and mitigation strategies, which are essential for developing resilient, welfare-conscious livestock systems in the face of ongoing climate variability.

References

Chen, L., Thorup, V.M., Kudahl ,A.B. & Østergaard,S., 2024. Effects of heat stress on feed intake, milk yield, milk composition, and feed efficiency in dairy cows: A meta-analysis,
Journal of Dairy Science,Volume 107, Issue 5, pp. 3207-3218, https://doi.org/10.3168/jds.2023-24059 

Moore, S., Costa,A., Penasa, M & De Marchi, M. 2024. Effects of different temperature-humidity indexes on milk traits of Holstein cows: A 10-year retrospective study. Journal of Dairy Science, Volume 107, Issue 6, 3669 – 3687. https://www.journalofdairyscience.org/article/S0022-0302(24)00015-8/fulltext

Forbes, J. M., 2007.Voluntary Food Intake and Diet Selection in Farm Animals (2nd ed.)
CABI Publishing. https://www.cabidigitallibrary.org/doi/book/10.1079/9781845932794.0000

Kadzere,C.T., Murphy, M.R., Silanikove, N. & Maltz, E., 2002. Heat stress in lactating dairy cows: a review. Livestock Production Science, Volume 77, pp 59-91. https://doi.org/10.1016/S0301-6226(01)00330-X.