Table 1 Blood flow variables in the milk vein of 5 dry cows, 5 cows with a daily milk yield of 10 kg and 5 cows with a daily milk yield of 20 kg (mean, sd, min., max.)
| Â | Group | ||
|---|---|---|---|
Variable | Dry | 10 kg milk | 20 kg milk |
Distance between vein and skin surface (cm) | 0.53 ± 0.12 (0.37 - 0.64) | 0.45 ± 0.11 (0.33 - 0.63) | 0.44 ± 0.05 (0.39 - 0.50) |
Diameter of vein (cm) | 1.93 ± 0.39 (1.47 - 2.54) | 1.88 ± 0.77 (1.30 - 2.97) | 1.99 ± 0.46 (1.52 - 2.58) |
Maximum blood flow velocity (cm/s) | 14.04 ± 2.04 (12.0 - 16.8) | 38.77 ± 15.17* (15.6 - 56.1) | 39.49 ± 8.28*(28.5 - 50.6) |
Minimum blood flow velocity (cm/s) | 0.63 ± 0.26 (0.3 - 0.9) | 3.02 ± 1.53* (1.0 - 5.1) | 2.64 ± 0.61* (2.0 - 3.6) |
Mean maximum blood flow velocity (cm/s) | 8.21 ± 1.69 (6.5 - 10.6) | 26.67 ± 11.91* (8.8 - 40.6) | 28.22 ± 5.41*(21.7 - 33.0) |
Blood flow volume (l/min) | 0.79 ± 0.29 (0.4 - 1.2) | 1.80 ± 0.72 (1.3 - 3.0) | 3.09 ± 1.46* (1.8 - 5.3) |