Table 2.
Behavior and heart rate during the social test and the novel environment test (mean ± SEM) of calves in individual pens with auditory contact (I), individual pens with auditory and visual contact (V), individual pens with auditory, visual, and tactile contact (T), or pair housing (AP)
| Item1 | Treatment |
F-value | P-value | |||
|---|---|---|---|---|---|---|
| I | V | T | AP2 | |||
| Social test | ||||||
| Latency sniff calf3 (s) | 22.4a ± 1.52 (502) | 18.0b ± 1.54 (324) | 17.8b ± 1.51 (317) | 14.6c ± 1.29 (213) | F3,30 = 9.59 | <0.001 |
| Sniffing/licking muzzle3 (s/10 min) |
0.46a ± 0.31 (0.21) | 0.96ab ± 0.32 (0.94) | 1.33b ± 0.31 (1.82) | 1.61b ± 0.22 (2.59) | F3,30 = 3.69 | 0.03 |
| Sniffing/licking head/body3 (s/10 min) |
0.97 ± 0.46 (0.94) | 1.59 ± 0.47 (2.53) | 1.36 ± 0.46 (1.85) | 2.06 ± 0.38 (4.24) | F3,30 = 2.17 | 0.11 |
| Sniffing wall/floor3 (s/10 min) | 12.5 ± 0.93 (156) | 10.7 ± 0.95 (114) | 11.4 ± 0.94 (129) | 10.1 ± 0.69 (102) | F3,30 = 1.79 | 0.17 |
| Lines crossed3 (no./10 min) | 4.64 ± 0.90 (21.5) | 5.95 ± 0.89 (32.3) | 6.04 ± 0.88 (36.5) | 6.43 ± 0.70 (41.3) | F3,30 = 1.32 | 0.29 |
| Mean heart rate (beats/min) | 159 ± 6.0 | 168 ± 5.8 | 160 ± 6.0 | 155 ± 4.9 | F3,30 = 1.83 | 0.16 |
| Novel environment test | ||||||
| Areas entered3 (no./10 min) | 6.57 ± 0.46 (43.2) | 5.97 ± 0.46 (35.6) | 5.56 ± 0.45 (30.9) | 5.87 ± 0.32 (34.5) | F3,30 = 0.90 | 0.45 |
| Mean heart rate (beats/min) | 160a ± 5.3 | 152ab ± 5.5 | 143b ± 5.2 | 139c ± 4.3 | F3,30 = 4.85 | 0.007 |
a–c
Within rows, values with different letters are significantly different (P < 0.05).
1
The social and novel environment tests were conducted when the youngest calf in a block was 44 and 46 d old, respectively.
2
Treatments P and VP pooled, where P = pair housing within 3 d of birth, and VP = auditory and visual contact the first 2 wk followed by pair housing.
3
Values were square root transformed before analysis. Back-transformed mean estimates are given in parentheses.