Summer doesn’t have to be a bummer for your lambs

Four simple steps can help your lambs beat the heat.

For many people, summer is the time for family vacations, days at the pool and watching fireworks. But for growing spring-born lambs, hot summer weather can bring on health and performance challenges. These challenges can affect lambs for their entire life.

“Heat stressed lambs could experience a decrease in growth rate due to a loss of appetite and suppressed immunity, which can lead to other health challenges,” says Julian (Skip) Olson, DVM, technical services manager for Milk Products. “Sheep are most comfortable at 45-70 degrees F. When humidity sets in or temps go above 75 degrees F, sheep begin to feel the negative effects of the heat.”

These four tips can help your flock stay comfortable and healthy all summer long.

1. Hydration is key

“Growing lambs need to drink water more often than adults due to a higher metabolism rate,” says Olson, adding, “And, with a greater percentage of their body weight being comprised of water in comparison to adults, providing access to fresh water at all times is a must.”

On average, growing lambs will drink 1 to 2 gallons of water per day. During times of heat stress, sheep water consumption typically increases by 50 percent once temperatures reach 70 degrees F and by nearly 100 percent at 80 degrees F.[1]

During periods of heat stress offer your sheep free-choice electrolytes with their water 2-3 times per day. Electrolyte supplements containing electrolytes, energy and amino acids are designed to help replenish fluids and lost nutrients.

2. Shade and ventilation are essential

Just like people seek air conditioning during the hot days of summer, shade gives your flock a break from the sun’s heat.

A range of shade options are available and can fit many budgets. Natural shade may include large trees, bushes and even stacks of hay. If natural shade is not available, shade cloth, mesh fabric or even a tarp can work, amongst many other options.

“Regardless of the shade option you choose, it is important to provide enough shade for the entire flock to lie down at the same time,” says Olson.

If housing your sheep in a permanent structure such as a shed or barn, it is important to provide ample ventilation. An effective ventilation system during warm weather cools the building by replacing the warm air inside with fresh air and removes excess moisture. Proper ventilation can be achieved either naturally (without fans) or mechanically (with fans).

3. Provide adequate nutrition

Having quality forage on hand is essential, as pasture quality is typically lower during hot weather. A high-quality grain mix is also recommended to help offset reduced growth rates during warm weather.

Hot weather can also reduce ewe milk production. If your lambs have not been weaned, ensure they are receiving enough energy to grow and thrive.

“If milk production drops in heat-stressed ewes, supplemental liquid nutrition is needed. Look to a lamb milk replacer containing at least 23 percent protein and 30 percent fat,” says Olson. “Milk replacer needs will vary depending on your lamb’s weight and appetite, so be sure to read the bag instructions to ensure you’re providing adequate nutrition.”

 4. Know how to identify heat stress and act immediately

 Despite your best efforts, heat stress may be inevitable in some cases. Watch for these clinical signs of heat stress and work with your local veterinarian to assess each lamb or ewe:

  • Continuous panting
  • Rapid breathing
  • Weakness
  • Inability to stand
  • Elevated rectal temperature (over 105 degrees F – rectal temperature exceeding 107 degrees F can be fatal)

“Avoid rinsing lambs with water to cool them off,” says Olson. “While evaporative cooling works well with many other animals, this is not the case with sheep. Air flows through the wool, which helps regulate body temperature. When wool is wet, air is not able to flow through to the skin to initiate cooling.”

Learn more about caring for lambs and lamb nutrition or like My Farm Journey on Facebook.


[1] Pennington, J. July 2014. Sheep and goats in summer heat and humidity. University of Missouri Extension Ag News & Views. [accessed 2017 March 15].