USDA's Agricultural Research Service issues heat stress forecasts using the seven-day forecasts of four heat stress parameters: temperature, humidity, wind speed and cloud cover from the National Weather Service.
These maps are to be used as an estimate of general trends of stress levels over the forecast period. The maps are also designed to forecast the anticipated peak heat stress category for each day.
Here is the forecast for today.
Why track heat stress?
In the last ten years there have been several heat events in the Midwest; direct and indirect financial losses for these events are estimated at more than $75 million for the cattle industry.
These weather events are unavoidable, but management strategies can reduce the impact of heat waves. Advance notice combined with heat stress management plans can help minimize the losses. This USDA website was developed to provide cattle heat stress estimates based on the National Weather Service seven-day forecasts and heat stress research done at the U.S. Meat Animal Research Center.
What are cattle risk factors for heat stress?
Factors can be grouped in four different areas. These areas are genetics, health, production status, and previous exposure to heat stress.
What are environmental risk factors?
The following factors may contribute to a more intense heat event than indicated:
- saturated soils at or near the feedlot
- recent rain
- irrigated cropland
- leaking stock tank
- high overnight lows (above 70? F)
- danger or extreme conditions for 2 or more consecutive days
- minimal cloud cover
- low or no air movement
- high relative humidity
Conditions at a particular feedlot may be different than either the forecast has indicated or that the local public weather station is recording. This can be due to natural variation in weather or local landscape. Feedlots in low lying areas or with large windbreaks may experience more serious conditions than indicated on the forecast map.
What are actions to minimize heat stress?
Actions to be taken before an extreme heat event:
- Monitor the weather.
- Prepare a summer feeding program, which is a low heat increment diet, to feed the cattle during heat waves.
- Ensure that there are no restrictions to air movement such as hay storage locations or wind breaks.
- Check stock tanks to ensure adequate water and consider the use of additional water tanks.
- Consider added shade at least over the sick pens, and possibly over other vulnerable animals.
- Remove manure build up from around water tanks, feed bunks and under shade. Manure build up should not exceed 1 inch in depth.
Actions to take during an extreme heat event:
- Do not move animals.
- Observe animals for signs of heat stress.
- Consider wetting the animals or the ground.