BOARS NEED HELP HANDLING HEAT Summer can sap your boars of their fertility. The danger is you may not realize it until long after the damage is done.
You need to help keep boars cool in extreme heat to avoid seeing litter sizes drop come fall.
Boars begin to be affected by heat at 82 degrees Fahrenheit,” notes Sasha Gibson, artificial insemination director at International Genetics A.I. Services in Maple Park, Ill. “At 91 degrees, most boars suffer serious problems. At those temperatures and higher, semen production can be severely affected.”
Boars suffer reproductive problems if temperatures stay above the critical level three days or longer. Problems may also surface if temperatures fluctuate drastically, for example 20 degrees or more, in a day, Gibson says.
Charles Schelkopf, a Sycamore, Ill., veterinarian, notes heat stress can affect boar fertility for up to six weeks after the stress period ends. He says boars may not seem ill and semen volume may not drop.
However, undetected heat damage to sperm can reduce litter sizes and drop farrowing rates. Testing sperm motility and checking abnormalities with a morphology test are the only sure ways to know if your boar is underperforming.
How might this affect an operation? A 500-sow unit may experience up to two months of summer infertility problems, according to Gibson. If litter size falls even by a half pig and the farrowing rate falls 20 percent, the operation would see a $12,840 drop in income. That’s a huge impact in any economic climate, she points out.
While Schelkopf notes that you can’t cure the problem, you can keep boars cool to avoid heat stress. You can supply boar housing with sprinklers, evaporative coolers, increased ventilation or perhaps even air-conditioning.
What can you do after your boars suffer heat stress? Rather than gamble with low productivity, consider buying semen and using artificial insemination. Gibson says you need to make sure you buy semen from boars housed in a moderate environment.
If your boars avoid heat stress, you take a big step toward keeping farrowing rates and litter sizes constant all year round.