A big percentage of a hog barn’s environmental drawbacks can be eliminated simply by keeping the barn at the right temperature and reducing dust.
Stephane Lemay and Liliane Chenard of the Prairie Swine Centre in Saskatoon presented a paper at the centre’s satellite conference Feb. 17 that said better management of water and heat also improves a barn’s profits.
For example, nipple drinkers are the most common form of water system in hog barns, but growing-finishing pigs can waste up to 60 percent of the water from such systems.
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“Considering pig water intake and potential wastage from the drinker, an important amount of water flows directly from the barn to the lagoon and this water will have to be spread in the field,” Lemay said.
Based on a growing-finishing diet, pigs use about 2.5 litres of water per kilogram of feed. In a 5,000 head barn turning over 2.8 times a year, assuming waste of only 40 percent, you’d waste about 13.23 million litres of water a year.
To spread that extra water as part of the manure slurry would cost about $8,600 a year or 61 cents a pig, Lemay said.
In new barns or in renovations, more efficient bowl feeders or wet-dry feeders should be used. Leaking pipes should also be fixed.
If nipple drinkers are used, set them at the right level: shoulder height for the smallest pig in the pen for nipples that come out from the wall, and if the nipples are tipped downward, pigs should have to lift their heads slightly.
Lemay also said barns that are too warm waste heat and money. Recommended barn temperatures in winter for grower-finisher operations are 21 C for pigs at 25 kilograms, stepping down to 15 C for 75 kg pigs.
Leaving the heat at 21 C as the pigs grow could increase costs by about 20 cents a hog in Saskatchewan and Manitoba conditions.
As for air pollution, ammonia is a significant byproduct from hog manure.
“The soiling of surfaces with manure within the building increases the air/manure contact area and thus increases ammonia emission rate,” Lemay said.
Keeping pens clean reduces gas emission. Also, dust particles are key odor carriers.
“Dust concentrations in ventilation air flow is responsible for a large portion of building odor emissions. If dust concentrations are reduced in the building, they will also be decreased at the fan level and consequently, total building odor emission will be reduced,” he said.
Keeping feed spillage to a minimum, using feed additives and spraying barns with water or canola oil can keep down dust.
Lemay noted a study that showed a biomass filter used to remove dust particles from a swine nursery led to odor threshold levels dropping by 50-90 percent between the inlet inside the barn and the outlet outside.
