Materials and Methods
Six freestall barns, three naturally ventilated (NV) and three tunnel-ventilated (TV), were selected for evaluation in this study (Table 1). One barn of each type was selected in central New York (NY), central Ohio (OHC), and western Ohio (OHW), with the two barns in each region being reasonably close to each other (no more than 20 miles apart). The selected operations demonstrated generally accepted management practices and had primarily Holstein herds with above-average production.
| Farm ID | Primary system | Building dimensions | Barn Orientation | Stalls | Fans | |||||
| L (ft) | W(ft) | H*(ft) | # | Rows | # | Dia. (in) | Loc.** | |||
| NV-NY | Natural | 390 | 86 | 12 | N-S | 360 | 4 | 50 | 36 | F & St |
| TV-NY | Tunnel | 874 | 96 | 9 | N-S | 1,080 | 6 | 20 | 60 | S. end |
| NV-OHC | Natural | 256 | 100 | 9-12 | E-W | 200 | 4 | 6 | 48 | F & St |
| TV-OHC | Tunnel | 160 | 110 | 10 | N-S | 186 | 6 | 22 | 48 | N. end |
| NV-OHW | Natural | 256 | 112 | 12 | N-S | 312 | 6 | 16 | 51 | Stalls |
| TV-OHW | Tunnel | 160 | 114 | 10 | N-S | 200 | 6 | 21 | 51 | S. end |
| 1NV = naturally ventilated, TV =
tunnel ventilated, NY = New York, OHC = Central Ohio, OHIO =
western Ohio, L = length, W = width, H = heighth, N = North, S =
South, E = East, W = West, F = feeding lanes, and St = f
reestalls.
* Eave height ** F & St indicates that fans were situated over feeding lanes and an inner row of freestalls |
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