In hutch housing when the bedding is wet and dirty in cold winter weather, dairy calves are in a bind. "If they lie down inside they lose a lot of body heat down through the wet bedding,” says Sam Leadley, PhD, Attica Veterinary Associates, P.C., Attica, N.Y.
“There is no nesting effect so convection body heat losses are excessively high. And, it stinks in there — ammonia levels are well above what is healthy. They can go outside to lie down if the weather is sunny and dry, but snowy nights are something else. Where can they go to rest?"
The most common mistakes, therefore, are:
- Not adding enough good quality bedding to maintain a clean and dry resting base. Leadley says “good quality” is the key because he occasionally sees in Midwestern states producers trying to use soybean waste or chopped corn stalks as calf bedding. “The former has a low absorption capacity. The latter is usually too high in moisture to act effectively as insulation.”
- Failing to move the oldest calves out of hutches promptly. Leadley says the bedding area in a hutch is too small for 170–200 lb. calves. “They eat, pee and poop a lot so it is almost impossible to keep them clean and dry, but many farms often get overloaded in the first group pens and animals back up in the hutch housing.”
In barn housing when the bedding is wet and dirty in cold weather the calves are in the same bind as in hutches — loss of body heat down and out. And, they may be stuck with poor air quality issues worse than hutch calves because not only is their own bedding generating noxious gas but they may be forced to breathe “barn air” that contains excessively high levels of airborne pathogens. Leadley says the most common mistakes made for wintertime ventilation in barns are:
- Too little air exchange (humidity is too high, pathogen concentration is too high, noxious gas load is too high).
- Not adding enough good quality bedding to maintain a clean and dry resting base.
- Failing to move the oldest calves out of individual pens promptly.
- Housing transition calves in the same air space as the preweaned calves.
Read the full article in Bovine Veterinarian on reducing winter calf pneumonia here.