While the number of pigs in barns and marketed this summer will be reduced because of PEDv, this hasn’t stopped the construction industry. There are still going to be quite a few new wean-finish and grow-finish facilities constructed in the Midwest this summer and final decisions are being made about a large number of these barns in the coming weeks as spring thaw finally reaches our region.
I get the opportunity to review quite a few plans each year and I’ve come up with the following check-list for those of you considering new/remodeled facilities:
1) What have you done at your entry point to enhance biosecurity? Ideally this will be a bench entry system so no outside footwear is worn into the barn.
2) What about a sink at the entry point to wash hands going in? We change boots and coveralls, yet all too often we enter pig spaces with hands contaminated from other barns/rooms/sites. I see a lot of field men who visit several sites in a day use disposable gloves at each site to reduce this biosecurity risk.
3) Do you really understand what you builder and equipment supplier is proposing for the ventilation system and fan staging? Just because the last 5 barns they were involved in chose to do it one way does not mean that it is correct.
4) What about soffits and attic inlets for the ventilation system? In the 1964 Nebraska Swine Report E.A. Olson, extension ag engineer recommended 1.5 sqft of attic inlet per 1000 cfm. The animal scientists and ag engineers who conduct the 4-state ventilation workshops recommend 2.5 sqft per 1000 cfm in order to minimize static pressure constraints on fan performance. This is effective opening (not punched metal or other restricted soffit material) and I often see designs that are less than 1 sqft per 1000 cfm when the west/north soffit is closed in winter to prevent snow drift into the attic.
5) Even if the soffit/attic inlet is correctly sized, are the insulation chutes/stops correctly installed? A 6-8” soffit opening is only as effective as the clearance elsewhere. I’ve seen too many ‘chutes’ installed that result in a net opening into the attic of only 3”, severely restricting the ventilation systems performance and resulting in higher than necessary electric expenses.
6) For curtain barns, does the ventilation system provide a total of more than 35 cfm/pig capacity before requiring the curtain to open for heat relief? The lower the total fan ventilation capacity, the colder it is when the curtains must open for heat relief. Many curtain facilities have rusted soffits and roof steel on the SW quadrants of their barns because inadequate ventilation capacity results in steam condensing in this region when the curtains open on cold days.
7) For tunnel barns, is there at least 45-50 cfm of ceiling inlet capacity before it is necessary to open the tunnel curtain? If not, the tunnel curtain opens for additional inlet capacity and heat relief when it is 50F or colder with bigger pigs in the facility.
8) Can the stage 1 fans meet the minimum ventilation requirement? For wean-finish, this is 2 cfm/pig. Remember, variable speed fans should never operate at less than 50% of their rated rpm or motor failure risk is increased. In addition, as you slow down variable speed fans, their ability to maintain ventilation is increasingly compromised when faced with head winds on the fan(s). Higher than necessary minimum ventilation rates will always result in higher propane expense.
9) What about your load out? Can the trucker enter his trailer without having to enter your facility or a point where the person bringing pigs from the barn doesn’t cross with every group of pigs? Can you build in a clean-dirty line for pigs leaving the facility? Can you wash/disinfect the load out facility?
10) If a tunnel barn, have you located the sick pen at least 40-60 ft in from the tunnel curtain? The sick pen should be the best pen in the facility, not the pen closest to the door.
11) If you have an office/entry area with a floor drain, is the drain located near the medicator and water valves or is it in the middle of the room? I prefer a recessed drain at the medicator point so any spillage is contained to that area and doesn’t wet the entire office/entry floor as it flows to the drain.