|Stall use was better in cross-vent barns than in similarly sized naturally vented barns in a recent Minnesota study.
Cooler in summer; warmer in winter. Cross-ventilated barns, with their continuous year-round ventilation systems, are purported to be better barns when it comes to cow comfort.
Results from a University of Minnesota (U of M) study comparing six cross-vent barns to six naturally ventilated freestall barns appear to bear that out.
All the barns were bedded with sand, and cow populations were similar, ranging from 500 to 1,700 cows, say Marcia Endres, a U of M dairy scientist, and her graduate student, Karen Lobeck.
Their findings thus far:
- Cross-vent stall use was about 5% better. "Both barns were greater than 70% on average, but in the heat of the summer, cows in the naturally ventilated barns used the stalls less,” Endres says.
- Lameness in the cross-vent barns was about 13% compared to 19% in the naturally ventilated barns. But severe hock lesions affected about 10% of animals in both barns. "That was a surprise, because all the cows were on sand,” Endres says. "Grooming of stalls may be an issue in all of these barns.”
- Air quality, in terms of ammonia and hydrogen sulfide levels, was poorer in the cross-vent barns. But gas levels were still below human and animal safety levels.
- Light levels were worse in the cross-vent barns, which had 12' candles versus 40' candles in the naturally ventilated barns. And light intensity decreases over time as dust and dirt build up on lights.
- No differences were recorded in body condition scores, hygiene scores or somatic cell counts.
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