As soon as the temperature rises, dairy cows’ behavior changes as well. They eat less, drink more, seek relief from the heat, and spend less time ruminating. This may seem like a logical response to hot weather, but the consequences for milk production can be significant.
The biggest challenge lies not only in the heat itself, but especially in the decline in feed intake. Lower dry matter intake means less energy, a greater metabolic burden, and a higher risk of rumen disturbances. Farmers who fail to address this in a timely manner will often see the consequences reflected in milk production, fertility, and animal health.
A well-thought-out combination of barn management, feed ration optimization, and targeted nutritional support helps minimize these effects as much as possible.
When do we say there is heat stress?
Dairy cows produce a lot of body heat, partly due to fermentation in the rumen. At high temperatures, it becomes increasingly difficult to dissipate that heat.
Within the industry, the Temperature Humidity Index (THI) is often used for this purpose. As a general rule:
- THI from 68: first signs of heat stress in high-producing dairy cows.
- THI above 72: a significant decrease in feed intake and milk production is possible.
- THI above 78: severe heat stress with increased health risks.
It’s not just temperature that plays a role. Humidity, solar radiation, ventilation, and wind speed also determine how much stress cows are under.
Recognize the early signs
Many dairy farmers don’t notice heat stress until milk production starts to decline. By then, the damage has often already begun.
Therefore, watch for early signs such as:
- an increased respiratory rate;
- less rumination;
- lower dry matter intake;
- increased water consumption;
- cows that stand instead of lying down;
- decreasing milk fat or milk protein;
- reduced activity.
It is precisely these subtle changes that indicate that the diet and the environment require extra attention.
Why the tripe is under pressure
When cows eat less, the fermentation process in the rumen also changes. Animals often consume larger portions during cooler times of the day. This increases the load on the rumen and raises the risk of fluctuations in rumen pH.
That is why heat stress is not just about temperature, but also about maintaining stable rumen function. A well-balanced diet helps to:
- to maintain feed intake;
- to support rumen fermentation;
- to use energy more efficiently;
- to keep milk production as stable as possible.
Management remains the first step
Before using dietary supplements, heat stress management always begins with proper management. For example:
- adequate ventilation;
- shade on pasture plots;
- unlimited access to clean drinking water;
- feed during cooler times of the day;
- regularly eating the food;
- reducing heat buildup in the feed ration.
These measures form the foundation upon which nutrition strategies can be built.
The Role of Nutrition During Hot Spells
A decline in feed intake calls for a diet that is utilized efficiently. Several factors play a role in this:
Ruval® supports the rumen
Ruval® is a liquid protein supplement that helps support rumen fermentation and improve nutrient utilization. Thanks to its natural betaine content, it also supports the osmotic balance of cells, which is particularly beneficial during hot weather.
Glycoboost supports energy balance
Around calving or during periods of lower feed intake, the energy balance can quickly come under strain. Glycoboost provides readily available energy and supports cows during phases when the risk of a negative energy balance or ketosis increases.
Acibet® TMR helps prevent heating
On hot summer days, a TMR ration heats up more quickly. This reduces its palatability, causing cows to eat less. Acibet® TMR helps keep the feed fresh and stable for longer, which helps maintain feed intake.
Why Natural Betaine Is Getting So Much Attention
Natural betaine has been used in animal feed for years because of its role as an osmolite. This means that betaine helps cells regulate their water balance when animals are exposed to stressors such as heat. Under various research conditions, it has also been shown that natural betaine can contribute to:
- more efficient use of nutrients;
- supporting rumen fermentation;
- maintaining dry matter intake during hot periods;
- Supporting milk production and milk components when heat stress occurs.
It is not a substitute for good management, but it is a valuable addition to a broader strategy.
A Practical Checklist for Hot Days
During summer conditions, check the following regularly:
- Is the water intake sufficient?
- Does the food stay fresh throughout the day?
- Is there enough air circulation in the barn?
- Does rumination remain stable?
- Is the meal served several times a day?
- Are there any noticeable changes in milk fat or milk protein?
- By taking action early, major production losses can often be prevented.
Conclusion
Heat stress cannot be prevented, but its effects can certainly be mitigated.
A combination of good barn management, a balanced diet, and targeted nutritional support helps dairy cows stay healthy and productive even during hot weather.
With solutions such as Ruval®, Glycoboost and Acibet® TMR Jodoco helps dairy farmers maintain feed intake, rumen health, and ration quality when conditions call for it.
Would you like to know which approach best suits your business? The specialists at Jodoco are happy to work with you and provide advice based on your feed ration, production, and business objectives.
