Heat Stress in Calves

Industry wide, there is significant focus on how heat stress impacts cow performance, but more often, heat stress in calves is overlooked. So, let’s review what heat stress looks like in your dairy replacement, or beef on dairy cross calves.

Behavioral responses:
• ↑ Standing time
• ↓ Feed intake
• ↑ Respiration rate and panting
• ↑ Water intake

Physiological responses:
• ↑ In blood flow (vasodilatation)
• Blood flow →peripheral tissue
• Respiratory alkalosis compensated by bicarbonate excretion
• Oxidative stress → demand for energy

Effects:
• ↓ Energy intake
• ↑ Energy expenditure
• Reduced performance

When a calf becomes heat stressed, it will increase standing time, reduce intake of starter and then milk, and increase its respiration rate and water intake. The panting causes a loss of water and carbon dioxide, which leads to respiratory alkalosis and a loss of bicarbonate through the urine as the calf tries to compensate for this stressor. They can also enter a state of oxidative stress, where the demand for energy will be higher, but because they’ve reduced their feed intake, the energy expenditure will be greater than their energy intake, leading to reduced performance. To help prevent negative impacts on performance, calves should be fed an electrolyte that supports hydration. A rehydration therapy electrolyte should be formulated to promote fluid intake, replenish lost electrolytes and provide some energy to support the calf’s recovery. Implementing an electrolyte into your program is an easy and cost effective way to help better the health and performance of your calves! At Denkavit, we have just the electrolyte formulated for heat stress situations!

For more information on hydration and electrolytes, or to discuss your calf rearing options, reach out to us today! Our young animal specialists are here to help ensure the best heatlh and growth for your calves.

Dr. Kayla Aragona
Technical Nutrition Lead
k.aragona@denkavit.com
603-455-0675