Heat stress occurs when the heat and humidity load is greater than the cattle’s capacity to lose it. During heat stress periods, cattle lose water and nutrients required for bodily function and performance. The combination of humidity and heat compromise’s a cattle’s ability to regulate their body temperature and once cattle fail to control thermal balance, they become stressed and the energy for production will be re-directed to thermal regulation. Here are our tips to help mitigate effects:
- Consumption can increase 30% during the summer.
- Ensure clean, fresh water with good access, adequate trough space and ensure flow rates can keep up with demand.
- Shade and cooling systems:
- Sprinklers and fans are effective when cows are exposed with heat stress. Only use misters and sprinklers where the environment and housing are suitable, where there is guaranteed air movement at cow level and where building have competent outlets.
- Remember stocking rates and ventilation. Make tweaks to buildings to improve the airflow.
- Do not forget dry cows and calves!
- Supplements and feed:
- To maintain optimal rumen function, adding supplements such as a buffer or yeast can help.
- Increase energy density of feed, to compensate for lower intakes.
- Ensure feed is palatable to encourage intakes.
- Consider feeding early morning and late afternoon when temperatures are cooler.
- High-risk animals (transition or sick cows)
- These animals are more affected due to their immune response. Encouraging water and feed intakes are critical.
- Handling of animals:
- Restrict handling to early morning and late evening, where temperatures are cooler. Remember not to overcrowd in pens as they WILL need the space for cooling. Limit the period they are contained to no more than hour.
- Manage the diet: move nutrients so that they are digested in the hind gut. The addition of protected and bypass feeds can enable this.
- Addition of supplements:
- The inclusion of supplements including yeasts and buffers can help mitigate the risk of heat stress and maintain gut integrity.
- NWF diets contain Cell Shield®, an anti-oxidant designed to optimise production and cattle health. It supports and regenerates vitamin E within the cow’s system, helping improve immune response.
For more information on combatting heat stress, read our dairy bulletin online HERE.
References: Techmix, 2019| Alltech, not dated| Pedersen, 2014|Farmers Weekly, 2019| Silmen et al., 2015| Dewell. 2010| Brown-Brandl, 2018