Suddenly it is summer.  Where did all this suffocating heat come from? Of course, if people are feeling soggy, you can be sure calves are feeling it too! Short of inviting them in to share the air-conditioning there are several effective ways we can keep calves cool and stress free.


  1. Shady Ladies.
    Make sure to provide your calves with plenty of shade whether it is from trees, the hutch itself or supplemental shade.  Hutches that faced south in the winter can be re-aligned to capture shade and prevailing breezes. If necessary, construct a temporary shade canopy over their tops (14 feet or higher to allow for good airflow).
  2. Timely Care.
    Consider changing the time of day when handling calves is done.   Perform stressful activities (such as moving, grouping, handling, vaccinating, dehorning) early in the morning. Feed animals several hours before or after peak temperature and humidity times. Early morning and late afternoon feeding can avoid calves experiencing peak temperatures at the same time as their digestion peaks, which often occurs about four hours after feeding.
  3. Always Fresh ‘Cause You Keep Feeding it.
    Keep your calf starter fresh at all times and free of any moisture. Start your calves with a handful of feed and change it every day until they are eating their full allotment.
  4. How’s the Water?
    Provide cool  (50°F /10°C) drinking water (cows drink 50% more water at temperatures of 80°F/26.7°C and above compared to 40°F/4.4°C). It should not be a surprise for calves to double their water intake. Switching to five-gallon pails may also be helpful.  When heat stressed a calf can consume 3 to 6 gallons of water per day. To keep it fresh, empty and refill water pails several times throughout the day. More water changes (say every three hours) the more they will eat. The more they eat the more nutrients they consume and then they are better able to withstand heat stress.
  5. There’s Strength in Numbers so Increase Feeding Frequency.
    Research has also shown that calves fed three times a day have shown optimal growth, better feed efficiency, consume more starter prior to weaning and have greater chance of survival to lactation than calves fed twice daily. You should also research commercial products that target heat stress in their formulations.
  6. Make Your Bed …again and again.
    Changing bedding frequently to control fly populations. Use sand bedding to keep calves cooler.  Clean, dry sand also helps control fly populations, compared with straw or sawdust. Sawdust is better than straw for summer bedding.
  7. Keep it Clean.
    Cleaning and sanitizing water buckets regularly Warm weather promotes algae, mold and bacteria growth. Keeping water and milk pails clean and sanitized will help keep these populations down, as well as help with the fly population.
  8. Replenish Electrolytes.
    Consider more liberal use of electrolyte solutions, advises J.W. Schroeder, Dairy Specialist with North Dakota State University. In warm weather, calves are more prone to dehydration. Scouring calves should receive oral electrolyte solutions liberally, particularly during midday. Administer electrolytes by bottle early in the course of diarrhea because solution absorption likely will be better than if it’s given by a tube or free choice.
  9. No Flies on Us! 
    Unfortunately calves are a hot spot for flies. Using a milk replacer and a calf starter that includes a feed through larvicide can help to keep the fly population down. A reduced fly population may also reduce stress to the calf and the spread of diseases by flies. As mentioned previously, clean, dry sand bedding also helps control fly populations, compared with straw or sawdust. Implement good fly control practices that break up the life cycle to prevent build-up. Know that molasses, a common calf starter ingredient to aid in palatability, can be a tasty attractant for fly populations. Calf starters that utilize alternative natural palatability enhancers along with feed-through fly control technology are available.
  10. A Breath of Fresh Air
    Increase Air Flow and air exchange:  Hutches need good air flow in and around them.  In enclosed facilities natural cross ventilation is not possible, than a total air exchange every two minutes through a mechanized system of fans is a must.

 ….. this brings us to the best TIP of the summer!

Catch the Breeze: Elevate one side of the hutch. That’s right.  A slight “tip” will make a big difference.  In 2011, a Washington State University trial showed that elevating one side of the hutch de­creased internal hutch temperature and increased ventila­tion in warm weather.  We all want results and here’s some that they reported:

  • At the hottest times of the day, internal hutch temperatures were higher than outside temperatures when the hutch was on the ground. Internal hutch temperatures were lower than outside when the hutch was elevated.
  • Elevating the hutch improved air movement within the hutch.
  • Hutch elevation lowered afternoon respi­ratory rates in the calves — 58 versus 44 breaths per minute.
  • Hutch carbon dioxide levels were lower when the hutch was elevated.

Note to readers:  We tried this simple solution at Huntsdale and saw – and felt – immediate results.


When we think of heat stress our thoughts often go to the milking herd first, as heat and humidity can have a dramatic impact on milk production and therefore have a potential impact on our pocket books. We need to think outside the cow pen. The numbers are rising as fast as the thermometer. For example: In a 100 cow herd with 30% cull rate, 25% of the calves in the herd are exposed to heat stress, having been born at that time of the year. Heat stressed open heifers may calve at 26 months instead of 24. Basic additional costs are obvious: extra days raising; more replacements costs; less production in the future. Not so obvious are extra housing, extra feed; extra labour and medication costs. Hopefully, you are still on the positive profit side with these numbers, however, there is a strong chance that these heifers will not produce to their potential. Add in those losses in less milk production and you have probably wiped out your small margin of success. Multiply this result over a 100-cow herd and you could see your positive bottom line melt away in the heat as you lose between $5,000-$7,000!!!


Extreme heat does hurt your calves.  Heat stress also hurts you …. in your pocket! Make sure you cash in on cool calves!!