Wednesday, January 16, 2013

Ventilation, Ventilation, Ventilation

A client and I talked yesterday about remodeling a calf barn from individual calf pens to group pens. The  4 group pens will be stocked with calves on an "All-in, All-out" basis. They are switching to an acidified milk replacer while the remodeling is going on while the calves are still being fed individually. So far, so good.

I asked about ventilation. "Well, we have curtains on three sides. Of course, with the cold weather things are pretty well buttoned up." [Building is rectangular twice as long as it is wide with axis running east - west. Third curtain faces north.]

"How cold has it been in the barn so far this winter?" I asked. "Has the water in the buckets frozen?"
I knew there has been at least a week with overnight temperatures around 20F in late December, early January. If there was good air exchange there should have been at least a film of ice on the buckets.

"No, no ice in the water pails so far this winter." Well, it really is "buttoned up."

Is this a catastrophe waiting to happen when they switch to group housing? In my opinion, the level of air exchange is too low to be healthful now with individual pens. What will happen when they group calves together in four pens and they depend on care takers inexperienced in monitoring calf health in a group setting? Likely outcome is nearly all the calves treated one or more times for pneumonia before weaning.

My recommendations?

1. Start getting experience now managing curtains to take advantage of any natural ventilation available any time the outdoor temperature warms up close to freezing (taking wind into consideration, as well).

2. As part of the remodeling get the building measurements and work with the farm's consultant to design a positive pressure ventilation system to supplement the natural ventilation.  Get this installed BEFORE moving the calves into group pens with the ad lib feeders.

3. Use the guide for observing calves at risk for respiratory illness in order to identify and treat pneumonia cases very early. See Observation Guide Respiratory Risk
Note that the picture guide is the second page at this site.  I use this guide regularly as I walk calves on my clients' farms.  


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