Avoid the Summer Slump: Feed and Management Tips for Hot Weather

By Tricia Wood, PhD, Technical Services – Ruminant, Lallemand Animal Nutrition
 
As summer settles in, volatile temperature swings and extended stretches of heat and humidity can challenge even the best-managed dairy herds. One of the most immediate impacts of heat stress is a decline in dry matter intake (DMI), which reduces nutrient availability and puts herd performance at risk. Staying ahead of the seasonal pressures on feed quality and intake is key to maintaining consistent production despite the weather.
 
Control Silage Heating and Spoilage
During summer, silages and haylages are naturally warmer, creating an ideal environment for spoilage yeasts and bacteria to take hold. As these microbes grow, they consume valuable nutrients, drive up silage pH and trigger aerobic spoilage. By the time mold appears, significant heating and deterioration have already occurred — lowering ration palatability and intake.

Best practices to manage forage quality in summer:

 
Support Rumen Function Through Heat Events
Reduced DMI and variable feed intakes during hot weather can disrupt rumen balance, leading to digestive upsets and lowered fiber digestion. This not only affects cow comfort but also compromises overall herd performance.

Adding a rumen-specific yeast probiotic, such as Saccharomyces cerevisiae CNCM I-1077, can help:

This nutritional tool helps keep cows on feed and reduces the negative performance impacts associated with heat stress.
 
Tighten Feeding and Water Management
Feed and water management become critical during heat events, as cows naturally reduce feed intake when temperatures rise. To help support intakes:

These simple adjustments help maximize DMI and limit the negative effects of heat on herd production.
 
Stay on the Offensive This Summer
As temperatures fluctuate, prioritizing forage hygiene, rumen health, and cow comfort can help minimize the drop in feed intakes and keep performance consistent all summer long.
 
Connect with your Lallemand representative to review your summer management strategy and see how tools like MAGNIVA® inoculants and LEVUCELL® SC can help protect feed quality and cow health through heat stress.