Electrolyte supplementation for gestating beef cows under heat stress conditions: cow-calf performance, thermotolerance and physiological responses

Lay Summary Heat stress is a major challenge for beef cattle raised on pasture, reducing cattle health, productivity, and comfort. Electrolyte supplements can be used to support hydration and metabolism, but their effectiveness has not been well studied in grazing beef cows. We tested whether adding an electrolyte solution to the drinking water of pregnant beef cows during late summer could improve hydration, heat tolerance, or overall performance. Fifty-four cows grazed bermudagrass pastures for about 90 days before calving and received either plain water or water mixed with an electrolyte product. The electrolyte supplement did not change water intake, body weight, body condition score, internal temperature, or respiration rate. However, cows receiving electrolytes showed improved hydration and acid–base balance, based on blood measurements. These cows also consumed less loose mineral mix, which may have reduced the overall impact of electrolyte supplementation.