Managing Heat Stress in Young Calves

Being able to raise healthy calves into mature animals is a goal for every dairy or beef farmer. Numerous studies have shown a positive correlation between keeping calves healthy while young, leading to healthy mature cows. Stress is one of the biggest factors when talking about calf well being, once a calf is stressed changes in overall performance and health decrease. Discussion around environment, sanitation, and feeding practices are all key factors in managing heat stress in calves. 

Fortunately symptoms of heat stress are straightforward and easy to identify, some of them include:

• Calf’s body temperature will increase above 103 °F.
• Increased respiration rate.
• Loss of appetite.
• Decrease in activity.
• If dehydration occurs -, there will be less urine output and manure will become firmer.
• Increased water consumption.

Environment of the young calves is one thing as a farmer, you have the control to manage. Having a good environment for your calves is the basic step of raising healthy stress free calves. The first step is having clean and dry bedding as the base step for an effective environment. This will decrease insect population, keep your calves dry, and limit bacteria growth in the bedding. Having a ventilation system in place will help keep the calves cool, and help with flies being able to bite the calves. On the other hand, too much breeze or draft is detrimental to the calves body, keeping steady airflow is the best thing to do for the calf. 

Poor ventilation can cause many problems including:

• Impair a calf’s immune response.
• Cause respiratory problems.
• Make the calf more prone to pathogens.
• Reduce feed intake and conversion rates.

Sanitation is an important factor during any season of the year, but during a hot season bacteria growth increases. Steps to help increaseing sanitation on your farm start with isolating sick calves, using clean pails, and disinfecting all equipment going near the calves. 

According to the University of Minnesota, steps to properly clean feeding equipment:

1. Rinse off dirt and milk residue with lukewarm water.

2. Manually scrub with a brush using hot water. Use a chlorinated alkaline detergent.

3. Rinse with warm water in an acid solution.

4. Let dry.

5. Sanitize with a 50 parts per million solution of chloride dioxide within two hours of use.

Feeding practices and nutritional management in calves change when the weather starts to heat up between 68-71 Temperature Humidity Index (THI). On a warmer day a calf's body temperatures will increase, meaning their energy will be utilized to regulate their body temperature back down to 102.1 degrees. To combat this as farmers you need to be adding more liquids to the calves' diet to substitute the water loss the calf will be experiencing. It is recommended by South Dakota State University Extension, to have your calves drink 6 to 12 quarts of water per day, and sick calves experiencing heat stress drink up to 20 quarts of water per day. 

Managing the environment, sanitation and feeding practices will be a positive step forward for decreasing heat stress, and effectively raise calves into healthy cows.