Environmental challenges of raising pigs in the upper midwest

With the mild fall in southern Minnesota and Iowa, pig performance has been outstanding based on the closeouts I’ve seen recently from client sites. With new crop corn and the ability to keep barns within the thermal-neutral range, feed intake has been impressive. This has driven daily gain (and sale weights). I know many producers have had grow-finish closeout groups with daily gains above 2 lb/d.

Other than bouts of influenza, pig health has been very good also which further contributes to this outstanding performance.

The biggest problem I’ve seen in recent weeks is barns that are ‘buttoned’ up for typical December and January temperatures. With daily highs as much as 10-20F above ‘normal’ these ‘buttoned’ up barns have been unable to respond to the need for heat removal and we’ve ended up with pigs experiencing mild heat stress. While not as severe as typical summer heat stress conditions, these mild stresses will still limit daily gain as the pigs immediate response when it gets warm is to reduce feed intake, meaning daily gain will suffer.

Unusually mild temperatures this fall versus ‘normal’ highlight the challenges of pork production in the upper Midwest. As I travel the world working with pork producers, it is difficult for many to understand the range of conditions that we experience. Summer high temperatures of 95-100F with dew points of 70F. Winter lows of -25F with blizzards making it very difficult to even get to sites for daily pig care.

I often get asked about European ventilation systems and their possible application in facilities in our region. Based on my experiences to date, a key question to ask is – can the system handle the range of temperatures (and wind) that are common to our region? While pig producing regions in Europe can get cold on occasion, they don’t often see 45 or more consecutive days when the temperature gets to freezing. They also don’t see 7-10 day periods with daily high temperatures above 90F.

Many European systems rely on some type of chimney fan. The goal is to exhaust dust and odors upward to get more mixing (dilution) of these pollutants before the exhaust plume leaves the producers site. A big challenge for us in adopting these types of fans is our steel roofs. Many of the pollutants end up on the roof, rusting out the steel around the fan relatively rapidly. This isn’t a problem in Europe where clay tile is a common roofing material.

We also locate our swine production facilities in the upper Midwest in an ‘un-barriered’ landscape. This means the facilities are often located at sites with minimal wind protection from either a shelter belt or other facilities. There is nothing around many of our facilities that modifies the wind’s effects on production facilities.

In contrast, much of Europe has production facilities with some type of barrier, be that other facilities at the site, trees or neighboring facilities. They also often don’t face the types of winds that we experience in the upper Midwest as warm and cold weather fronts battle for control of the atmosphere far from any modifying ocean currents.

2 thoughts on “Environmental challenges of raising pigs in the upper midwest

  1. Hello Mr Mike Brumm,I’M working at DBN Group in china which major in animal feed and swine rasing.May I ask some question about ventlation of hog barn?
    1.when I design how many fans use, how I can decide depend on the maxinum ventilation requirement or the max air speed the pig need(Tunnel Ventilation)?
    2.If I use ceiling air inlet when it’s cold in winter, how many ceiling inlet use depend on what? the mininum ventilation requirement or added others fans ventilation?

    my E-mail 254665430@qq.com or wrb20082005@163.com
    Thanks, I’m pleasure for your reply

  2. For tunnel ventilation we want at least 300 feet per minute air velocity at maximum tunnel staging to be sure we capture the impact of air movement over the pig to assist cooling. Generally though we are at 4-500 feet per minute because of the need to remove the heat produced by the pig. In the upper midwest this means tunnel fan capacity is often sized based on 1 air exchange every 35-40 seconds based on the room volume above the fully slatted floor. If we don’t exchange this much air we often end up with air temperatures at the fan end (exhaust) that are more than 3-5F warmer than the incoming air. Correctly designed, tunnel barns should only experience a 2-3F temperature rise from end to end when in the last stage of tunnel ventilation.

    As to ceiling inlets, tunnel barns are generally designed to get about 50 cfm/pig from ceiling inlets before having to open the tunnel curtain for additional inlet capacity. If you have less cfm/pig ceiling inlet capacity, the tunnel curtain must open when it is colder outside (less than 50F with bigger pigs) which ends up chilling the curtain end of the room.

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