Ventilation controllers

This is the time of the year when ventilation systems in swine facilities are cycling thru many stages. The cycling of the various fan and curtain stages is totally dependent on how the controller(s) is set, and the location of the temperature probes connected to the controller(s).


This morning I was in finishers that were experiencing a tremendous temperature variation due to improper controller settings. This afternoon I received a telephone call from a producer with a relatively new barn who is experiencing tail-biting on the first 2 turns of the barn when the pigs approach 150 lb body weight.


In both cases, the producers had constructed facilities that didn’t come with owners manuals. As such, they were having to learn how to operate the facility by trial and error. The consequences of the trial and error was pig performance compromises.


At the 2008 Minnesota Pork Congress I did a presentation entitled “Hog Barns Don’t Come with Owners Manuals” that details many of the little things that happen in finishing barns. You can access this presentation at:


This past winter, my talk was on measuring and managing energy costs. This talk can be accessed at:


The reason for citing these presentations is that they contain many of my recommendations for such items as set points, band width settings for variable speed fans, etc. Tail biting can be thought of as a discomfort syndrome, and having frequent large temperature swings in a facility, or forcing a pig to live in a barn where the inlets aren’t correctly adjusted often lead to tail biting and other behavioral vices.


In the case of the producers today, one had constructed a facility where the contractor had told him ‘I’ve got everything set right’ and left him to try and figure out what ‘right’ was. In the other facility, the set point temperatures were too high. This, combined with an inlet control issue resulted in conditions in the pig zone that were contributing to the tail biting.


The facilities we are constructing today are very advanced in terms of technology. The challenge many producers/growers/employees face is to fully understand how this technology works. While the general contractor often selects the equipment that is installed for the ventilation system, it remains the responsibility of the producer/grower/employee to fully understand how the system functions so that the end result is an environment in the pig zone that promotes rapid and efficient gain. All too often, there is no owners manual for these people to refer to and the end result if less than ideal pig performance.

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