Summer ventilation tips
Hot weather can be difficult and even dangerous for hogs if cooling systems are not functioning properly. Fans, cooling systems (such as misters), backup generators and alarms, all need routine testing and maintenance to ensure they perform when needed. The following are some suggestions for things to monitor so your pigs stay cool when the weather gets hot.
Fans and inlets
- Ensure all fans are working. Check fan belts and replace any that are slipping. Loose belts will decrease fan efficiency. Winter bandwidths are often set to 1.5-2F for variable speed stages in the winter. Moving these down to 1F in the summer will begin cooling pigs sooner when the temperature increases.
- Winter bandwidths are often set to 1.5-2F for variable speed stages in the winter. Moving these down to 1F in the summer will begin cooling pigs sooner when the temperature increases.
- Make sure fans are clean. Dirty fan housings and shutters greatly decreases fan efficiency.
- Sweep bird netting on attic eaves to avoid air restriction in attic space.
- Iowa Pork Industry Center resources on ventilation: https://www.ipic.iastate.edu/facilities.html
Emergency Backup Systems
- Emergency Curtain drops – test curtain drops regularly. Manually cut power to ensure magnets release, winches free-wheel, and curtains drop without hanging up. Also ensure the emergency curtain drop backup thermostat is functional and set to 95-100F.
- Emergency backup thermostats – test fan backup thermostats by adjusting temperature below ambient temp while watching for fans to cycle on.
- Test standby generators weekly – Most generators are set to automatically
test run weekly. However, this does not always mean they will function as intended in a power outage. To ensure proper function, simulate a power outage by cutting power to the site and monitor that automatic transfer switches function to bring on the generator. Testing generator under full load of fans and feedlines would be advised.
Cooling Systems
- Misters are an effective method of cooling for finishing pigs. It’s important to remember that pigs are cooled by water evaporating from their skin, not from cool water being applied to them. If pigs are not allowed to dry, they will not cool. The goal of misting pigs is to wet surfaces and allow them to dry and achieve evaporative cooling. Typical mister settings intervals of 3 minutes
on, and 27 minutes off will accomplish this.
- Stir fans are important to aiding evaporative cooling in naturally ventilated barns. Ensure stir fans work and are set to turn on at no higher than 85°F for
finishing pigs. - Tunnel ventilation settings — Tunnel ventilation can be locked out in the controller by setting minimum age. In extreme heat, this will prevent barns from entering tunnel ventilation, causing temperatures to reach dangerous levels with only attic ventilation.
- Cool cells — Wet cool cell pads reduce air-flow into the barn. Set timers to allow cool cell to be on long enough to completely wet the pads and off long enough so that the pads dry-out before another on cycle starts.
For more information on hot weather cooling, please contact your Swine Vet Center veterinarian.
Prepare your herd for seasonal infertility!
We are currently in the seasonal infertility period. This period is typically the time of year when it’s more difficult to keep
sows pregnant. The time frame is usually from Week 29 to Week 40 of the year. Heat is the biggest factor among several
contributors including decreasing photoperiod during weeks 34-40. Here are some tips to help decrease the impact of
seasonal infertility:
- Manage lactation feed intake — Decreased feed intake during lactation can
lead to a prolonged return to estrus. Sows that return to heat >7 days post weaning are more likely to have a lower conception/farrowing rate. Maximizing feed consumption during lactation can decrease this impact. - Supplemental cooling systems — Ensure cool cells are functioning properly and/or dripper systems are working. Supplemental
cooling will encourage sows to eat during summer heat. - Gilt supply — Take added steps to ensure an ample supply of gilts are available during this timeframe to take the place of weaned sows that may not have cycled.
- Increase breed target in weeks 29-40 — A 2-5% increase in breed target can
help compensate for the dip in conception rate and farrowing rate. Use your farm records to determine when a dip in conception is typically occurring and increase breed target accordingly. Monitor conception rate weekly and adjust breed target as needed. - Manage fallout — With decreased farrowing rate will come increased fallouts
to manage. When identified, move these sows to the opportunity row or cull
accordingly. Be diligent with 30 and 60 day preg checks. Do visual checks at 70-90 days bred.
Planning ahead for this yearly challenge can help to maintain the continuity on your farms and avoid any shortfalls in production. Any questions, contact a Swine Vet Center veterinarian. They’ll be happy to help you.
SVC Office Hours: Monday through Friday 7:30 AM to 5:00 PM
No portion of this newsletter may be used/copied without written consent of Swine Vet Center
