Table 3.
Latency to first, duration of (mean ± SD), and number of behaviors observed in pigs exposed to 80% CO2 and 95% CO2 for 346 s.
| Behavior1 | 80% CO2 |
95% CO2 |
||
|---|---|---|---|---|
| N2 | Mean ± SD | N | Mean ± SD | |
| States | ||||
| Duration of standing (s) | 24/24 | 31 ± 6a | 24/24 | 15 ± 4b |
| Latency to first walking (s) | 12/24 | 6 ± 9 | 14/24 | 9 ± 5 |
| Duration of walking (s) | 12/24 | 5 ± 3 | 14/24 | 2 ± 1 |
| Latency to first sitting (s) | 12/24 | 31 ± 3a | 12/24 | 14 ± 5b |
| Duration of sitting (s) | 12/24 | 3 ± 2 | 12/24 | 3 ± 3 |
| Latency to first lying (s) | 24/24 | 34 ± 5a | 24/24 | 17 ± 3b |
| Duration of lying (s) | 24/24 | 310 ± 5a | 24/24 | 328 ± 3b |
| Events | ||||
| Sniffing (s) | 24/24 | 18 ± 3a | 24/24 | 7 ± 2b |
| Latency to first retreat attempt (s) | 22/24 | 22 ± 6a | 20/24 | 10 ± 4b |
| Number of retreat attempts | 22/24 | 2 ± 1 | 20/24 | 2 ± 1 |
| Latency to first gasp (s) | 24/24 | 23 ± 4a | 24/24 | 9 ± 3b |
| Number of gasps | 24/24 | 30 ± 9a | 24/24 | 14 ± 3b |
| Latency to first lateral head movement (s) | 8/24 | 24 ± 10 | 12/24 | 14 ± 6 |
| Number of lateral head movements | 8/24 | 2 ± 1 | 12/24 | 1 ± 1 |
| Latency to first jump (s) | 12/24 | 34 ± 5a | 11/24 | 14 ± 2b |
| Number of jumps | 12/24 | 1 ± 1 | 11/24 | 2 ± 2 |
| Latency to first muscular contraction (s) | 21/24 | 36 ± 4a | 24/24 | 20 ± 6b |
| Number of muscular contractions | 21/24 | 4 ± 2 | 24/24 | 3 ± 2 |
| Loss of posture (s) | 24/24 | 44 ± 5a | 24/24 | 26 ± 5b |
| Number of escape attempts | 0/24 | – | 0/24 | – |
1First behavior when entering the gondola was always standing.
2Number of pigs showing the specific behavior.
T = 0 is start descending of the gondola into the well.
a,bMeans with different letters are significantly different (P < 0.05).