Hot summers are no longer a rare occurrence in the UK. In recent years, farmers across the country have faced more frequent heatwaves, prolonged dry spells, and rising overnight temperatures that leave cattle struggling to recover from daytime heat.

Kathryn Thompson :: Thursday 28th May 2026 :: Latest Blog Posts

Summer Feed Tips to Combat Heat Stress in Cattle

Hot summers are no longer a rare occurrence in the UK. In recent years, farmers across the country have faced more frequent heatwaves, prolonged dry spells, and rising overnight temperatures that leave cattle struggling to recover from daytime heat. Just recently we have seen May temperature records broken across the country. What was once considered an occasional challenge is quickly becoming a regular part of livestock management.

For dairy and beef producers alike, heat stress can have a significant impact on animal health, productivity, fertility, and feed efficiency. Reduced intakes, lower milk yields, and slower growth rates can all affect farm performance during periods of hot weather.

While ventilation, shade, and water access are all important, nutrition also plays a major role in helping cattle cope during summer conditions. By adapting feeding strategies early, farmers can help support rumen function, maintain performance, and reduce the impact of heat stress on the herd.

What Is Heat Stress in Cattle?

Heat stress occurs when cattle are unable to effectively regulate their body temperature. As temperatures and humidity rise, animals struggle to lose excess body heat quickly enough, placing additional strain on the body.

Cattle experiencing heat stress may show several common signs, including:

• Reduced feed intake
• Increased water consumption
• Panting or rapid breathing
• Drooling
• Standing for longer periods
• Reduced milk production
• Lower fertility performance
• Declining growth rates in beef cattle

High-yielding dairy cows are particularly vulnerable because digestion and milk production generate considerable metabolic heat. When hot weather combines with heavy production demands, the risk of stress increases significantly.

Even moderate heat stress can affect herd performance before obvious symptoms become visible. This is why preventative management is so important during warmer months.

Why Heatwaves Are Becoming a Bigger Challenge

The UK climate is changing, and livestock systems are feeling the effects. Heatwaves are becoming more common, with hotter temperatures lasting longer than many traditional housing and feeding systems were designed to handle.

One of the biggest challenges is the lack of overnight cooling. Cattle rely on cooler evening temperatures to recover from daytime heat. When nights remain warm, animals experience prolonged stress, leading to cumulative impacts over several days.

Hot weather also creates additional pressure on forage quality and grazing management. Grass growth can slow dramatically during dry conditions, while silage stability may become more difficult to maintain in higher temperatures.

These challenges highlight the importance of proactive nutritional planning. Feeding strategies that support rumen stability and encourage consistent intake can make a significant difference during periods of heat stress.

Encourage Feed Intake During Hot Weather

One of the first effects of heat stress is a drop in dry matter intake. Cattle naturally eat less in hot conditions as digestion itself produces heat. Unfortunately, lower intakes also reduce energy intake, making it harder for animals to maintain production.

Simple management changes can help encourage cattle to keep eating during warmer weather:

• Feed during cooler parts of the day, such as early morning or later evening
• Push up feed regularly to keep it fresh and accessible
• Remove stale or heated feed promptly
• Ensure rations remain palatable and consistent

Freshness becomes particularly important during summer. Warm conditions can increase spoilage and heating in total mixed rations, reducing feed quality and intakes.

Even relatively small drops in intake can quickly affect milk yield and growth performance, so maintaining consistency is essential.

Maintain Effective Fibre Without Increasing Heat Load

Fibre remains critical for rumen health, but balancing fibre levels during summer requires careful attention. Excessively fibrous rations can increase heat production during digestion, while insufficient fibre increases the risk of rumen upset and acidosis.

The goal is to provide effective fibre sources that support rumination without unnecessarily increasing heat load.

Farmers should monitor:

• Sorting behaviour at the feed fence
• Changes in dung consistency
• Rumination activity
• Sudden drops in butterfat or performance

Avoiding abrupt ration changes is also important. Consistency helps maintain rumen stability during periods when cattle are already under stress.

Water Intake Becomes More Important Than Ever

Water is often the most overlooked nutrient during hot weather, yet it becomes absolutely critical during periods of heat stress.

A dairy cow's water intake can rise dramatically during high temperatures, especially in high-yielding herds. If water availability is restricted in any way, performance and welfare can quickly suffer.

To support hydration:

• Ensure constant access to clean, cool water
• Check trough cleanliness daily
• Monitor flow rates and refill speeds
• Avoid overcrowding around water points
• Add additional troughs where necessary

In grazing systems, cattle may walk long distances to access water, reducing grazing time and increasing stress. Positioning water sources more effectively can help improve both hydration and intake.

Increase Energy Density Carefully

As feed intakes fall during hot weather, cattle still require sufficient energy to maintain production and body condition. This means summer rations often need to deliver more energy in smaller volumes of feed.

Using highly digestible ingredients and quality feed blends can help support energy intake without overloading the rumen.

However, balancing starch levels is important. Increasing concentrates too aggressively can raise the risk of acidosis, particularly when rumen function is already compromised by heat stress.

Working with a nutritionist to balance fibre, starch, and digestibility can help maintain performance safely during challenging conditions.

Specialist moist feeds and carefully formulated summer blends may also help improve palatability and encourage intakes when cattle become reluctant to eat.

Support Mineral Balance and Rumen Stability

Heat stress increases mineral losses and can place additional pressure on rumen function. Electrolyte balance becomes increasingly important as cattle lose sodium, potassium, and magnesium during periods of prolonged heat.

Supplementation strategies may help support hydration and overall performance during summer months.

Many producers also include live yeast products or rumen buffers to help stabilise rumen conditions and support digestion when intakes fluctuate.

Supporting rumen health during hot weather can help minimise performance losses and maintain feed efficiency across the herd.

Small Management Changes Can Make a Big Difference

Feeding strategies work best alongside good environmental management. A few practical adjustments around the farm can significantly reduce the impact of heat stress.

These include:

• Improving airflow and ventilation in housing
• Providing adequate shade in grazing systems
• Reducing handling during the hottest part of the day
• Minimising overcrowding
• Keeping bedding dry and comfortable

Monitoring cattle closely during heatwaves allows farmers to respond quickly before problems escalate.

Preparing for Future Summers

Heatwaves are becoming a more regular part of UK farming, and preparation is increasingly important. Reviewing summer feeding plans early can help farmers avoid reactive decisions when temperatures suddenly rise.

Checking forage stocks, assessing water systems, and planning nutritional support ahead of time can all improve herd resilience during hot weather.

At BW Feeds, we work with farmers to develop practical feeding strategies that support cattle health and performance throughout the summer months. From ration advice to specialist feed solutions, proactive nutritional management can help reduce the impact of heat stress and keep herds performing during increasingly challenging conditions.