Pigs often grow slower during the hot summer months than at other times of the year. This is especially true during July and August in the central part of Washington. As a result, pigs are delayed in reaching market weight which disrupts pig flow, feed efficiency and profitability in commercial units. Show pigs fail to make minimum weights for local and regional fairs and youth are very disappointed. Also, pigs are uncomfortable and their well-being may be compromised. Most of these consequences are preventable with proper management.
How hot is too hot for pigs from 50 to 260 pounds? Managers, including youth, should be on the alert at temperatures above 75 degrees. The Danger Zone is any time temperatures approach 100 degrees or above. Remember, pigs kept outside without adequate shade are going to be in the Danger Zone when the thermometer on your porch reads 80-85 degrees. Keeping pigs at temperatures in the Danger Zone represents inhumane treatment.
Pigs are more sensitive to heat and humidity than humans and some other animals like the horse. Don’t forget, pigs do not sweat! They cool themselves primarily by heat loss via the lungs, skin and urine. Therefore, providing cooler air for them to breathe, increasing consumption of cool water which will increase urinary water loss and providing water misting or dripping on their skin will all increase heat loss from their bodies and keep them cooler even when the thermometer rises above 80 degrees. Mud wallows partially accomplish the same purpose, but are not very sanitary and can spread diseases and parasites.
The key factors to monitor during the summer that may decrease rate of gain and feed efficiency and compromise animal well-being are 1) feed intake, 2) water consumption, 3) cooling and ventilation, 4) pig handling, and 5) space allowances.