Another day in southern Minnesota with a heat index above 100F and dew points in the mid 70’s. The impact of this extended heat on livestock have been many and will shadow us into next year.
This past week I spent a day with a production company working in various finishing barns reviewing their protocols and installation of cooling lines for cooling of growing pigs. The goal was to figure out what they were doing right this year and what changes to equipment installation and management of this equipment they should be thinking about before next summer.
One item that we quickly noted was the inability of the system as installed to get 60% of the pen area wet when the water was turned on. Given where the nozzles for the cooling line were located, only 25-30% of the pen was wet. This meant pigs fought to get weight which increased heat production, or failed to get wet, which decreased cooling. It was noted that when they tried to increase the amount of pen area that was wet, water drifted into feeders, resulting in wet feed and plugged feed systems.
In this case, the original nozzles were installed along the outside wall on the north and south pens in the middle of each 10 x 19 pen wall. The solution was to relocate the nozzle so it was over the gating between pens, on the gate that does not include the feeder. We experimented with nozzle location also so that we now can get 40-50% of the pen wet with large drops of water and still not have wet feed. Still not perfect, but a big improvement.
We also looked at the timing of wetting pigs. In this system, they use a ventilation controller that can turn of the cooling line at night so that floors dry and the risk of respiratory problems and feet and leg problems from continuously wet floors is reduced. Currently they were turning off the cooling lines at 1900 hrs or 8 pm and allowing them to come on in response to temperature at 6 am.
If you think about it, the coolest temperatures of the day are most often at 6-7 am, with the daily high recorded at 4-5 pm. While I agree with turning off the system for a period of time daily, I think you need to leave the system ‘on’ until at least midnight to help the pig deal with the heat accumulated in the facility. You can delay the start-up until 10 am on most days with little impact on overall effectiveness.