You are viewing Asia Pacific


Why Does Heat Stress Matter on Beef Cattle?

Heat stress is caused by a combination of weather and environmental variables, including high ambient temperature, humidity, solar radiation, and wind speed. Under high heat load, when the animal’s ability to dissipate body heat is impaired, additional body heat may be detrimental to the animal’s well-being, which leads to negative impacts on both animal welfare and the economic performance of production system. (References are available upon request)

Heat stress events causing mortality in feedlot cattle have certain environmental characteristics in common.
Predominants are a combination of two or more of the following:
  • Recent rain event 
  • High ongoing minimum and maximum ambient temperatures 
  • Absence of cloud cover with a high solar radiation level 
  • Low or no air movement over an extended period (4-5 days) 
  • High and ongoing relative humidity 
  • Sudden change to adverse climatic conditions (lack of an adaptation period)
Temperature Humidity Index (THI) - Beef

The beef cattle temperature humidity index chart demonstrates the risk level in planning cattle handling during the summer months. Cattle producers need to be aware of the risk of heat stress based on the weather forecast. The animal's core temperature peaks approximately two hours after the environmental temperature peaks and takes 4-6 hours to lower back to normal temperature.



Farmers in tropical regions—including large parts of Southeast Asia, e.g. Vietnam and Indonesia are particularly susceptible to heat stress due to temperatures ranging between 23°C to 32°C, and the average humidity is above 70% in a year. As well as in Northeast Asia countries e.g. Korea and Japan and Oceanic countries. Australia and New Zealand are also susceptible to significantly suffering heat stress. For example, In Queensland, the statewide mean annual temperature is 24.6° (between 2015-2019), and the region is prone to over 300 sunshine days per year. Thus, most animals will be exposed to conditions that could lead to heat stress.


Heat stress and leaky gut syndrome
Understanding the animal’s biological response to a heat stress event is critical to understanding the impact it could have on performance. Diversion of blood flow to skin and extremities occurs as the animal attempts to maximize radiant heat dissipation. The coordinated vasoconstriction in intestinal tissues results in:



Leaky Gut Syndrome (LGS) can broadly be defined as the inability of the intestinal barrier to prevent unwanted molecules inside the intestine from entering into the body . LGS results in increased intestinal permeability, which allows foreign substances to enter the body, and this stimulates an immune response that includes inflammation.
Activating the immune system

In order to combat an immune challenge, an active immune system in a Holstein steer requires more than 2,000 kilocalories in a 24-hour period. The glucose meant for economically relevant tissues will instead be used to support this immune function, reducing total production and profitability8.

Heat can be a major stressor on cattle. The energy expended to compensate for the impact of stress decreases the amount of energy available for productive purposes, including daily gain, immune system efficiency and muscle production. Chromium potentiates the action of insulin, which ultimately allows more glucose availability at the cellular level. Additional glucose is used by the animal in a hierarchical manner to help reduce the energy demand from stress events, such as difficult pen conditions and/or high ambient temperatures, to provide needed energy for productive purposes.

Beat the heat with KEMTRACE™ Chromium 

Do your cattle have everything they need to stay healthy and productive? If chromium supplementation isn’t part of your summer ration, the answer is likely no.

Evidence suggests insulin action is a key component of the heat stress response. Chromium improves insulin function and results in efficient clearance of glucose from the bloodstream. Increased glucose uptake may improve thermal tolerance in heat-stressed animals.

Let's Work Together! Contact Us: Contact Us