Individual housing of dairy calves prevails in Europe and North America despite its negative effects on calf development. One of the main reasons is that farmers find individual housing of calves more practical than group housing. A compromise between practice and welfare could be housing calves in pairs. Therefore, we aimed to compare health, feed intake, growth, and behavior in a novel arena of 22 individually (INDI) and 44 pair-housed calves that were randomly assigned a treatment. Diarrhea and respiratory problems were recorded every day for the period of 49 d. Intake of calf starter and milk were measured every day for the period 48 and 49 d, respectively. Calf body weight gains were calculated as average daily gain. Calves were individually tested in a novel arena at 11 to 18 d, and their behavior was recorded according to an ethogram including 8 behavioral categories. Behavioral categories were first diminished by principal component (PC) analysis. We found that 2 PC explained 66% of the total variation in calf behavior. Movement-related behaviors (activity, play, and crossing the stair) loaded positively on PC1, and PC2 had positive loading on self-grooming and negative loading on exploration. There were no effects of housing on calf health, feed intake, or average daily gain. The INDI calves had higher PC1 scores than pair-housed calves, indicating a rebound effect of movement. Our results are consistent with other studies that found no negative effect of pair housing of calves on their health, feed intake, or growth compared with individually-housed calves. The rebound effect of movement-related behaviors of INDI calves in a novel arena implies that individual housing of calves causes activity deprivation by the second week of age.

Most dairy calves are housed individually in early ontogeny but social housing has positive effects on calf welfare including an advantage of social buffering, i.e., when negative effects of stress are mitigated through social support of conspecific. The effects of social buffering has not yet been examined in relation to disbudding; a painful husbandry procedure commonly performed on young dairy calves. The objective of this study was to investigate the effect of pair versus individual housing on calves’ behavioral reaction to disbudding. In total 52 female calves were randomly allocated either to individual (n = 16) or pair housing (n = 36, 18 focal). Calves were hot-iron disbudded with a local anesthetic and their spontaneous behavior in home pens was recorded for 24 h pre- and post-disbudding. Eating forage, ruminating, resting, exploration, play, self-grooming, and pain-related behaviors were quantified during eight 20 min intervals during the 24 h periods pre- as well as post-disbudding. In pair-housed (PAIR) calves social resting, active and passive allo-grooming were additionally recorded. The differences between individually housed (INDI, n = 10) and PAIR calves (n = 12) were tested by general linear models. The changes in pre- and post-disbudding behaviors in all calves as well as in social behaviors of PAIR calves were tested by paired t-test. We found that head shaking (t =  − 3.46, P = 0.0024), head rubbing (t = 4.96, P < 0.0001) and self-grooming (t = 2.11, P = 0.04) increased in all calves after disbudding. Eating forage increased only in PAIR calves (t = 2.50, P = 0.030) which also resulted in a difference between treatments with PAIR calves fed more often than INDI calves (F1,18 = 12.96, P = 0.002). Differences in eating forage may be an indication of improved ability of PAIR calves to recover from disbudding. No other significant differences were detected between treatment groups which might have been caused by our limited sample. Our results provide the first evidence that housing treatment affects calves’ reactions to disbudding, with possible indication of social buffering.

Most dairy calves are housed individually in their early ontogeny but there is an increasing interest in housing calves socially. Social housing has many positive effects on calf welfare including an advantage of social buffering, i.e., when negative effects of stress are mitigated through social support of familiar conspecific. So far, social buffering has not been tested in relation to stress after disbudding, a painful husbandry procedure performed in young calves. Therefore, the effect of pair versus individual housing on calves’ reaction to disbudding was investigated. In total 50 female calves housed either individually (n= 14) or in pairs (n= 36, 18 focal) were used. Calves were hot-iron disbudded with a local anesthetic and their behavior in home pens was recorded 24 h pre- and post-disbudding. Feeding, ruminating, resting, exploration, play, self-grooming, and pain-related behaviors were quantified during eight 20 min intervals during the 24 h periods pre- and post-disbudding. In pair-housed (PAIR) calves social resting, active and passive allo-grooming were additionally recorded. Concentrate intake was measured 24 h pre- and post-disbudding. The changes of pre- and post- disbudding behaviors as well as differences between individually housed (INDI) and PAIR calves were tested by general linear models. The differences in pre- and post-disbudding behaviors of PAIR calves were tested by paired t-test. We found that head rubbing (t=-5.14, P<0.0001) and head shaking (t=-3.33, P=0.004) increased after disbudding. Feeding increased only in PAIR calves (t=-2.95, P=0.016) which also resulted in a difference between treatments with PAIR calves fed more than INDI calves (F1,18=12.27, P=0.003). We did not find any other significant differences. Our results provide the first evidence that housing treatment affects calves' reactions to disbudding, with possible indication of social buffering.

The objective of the study was to investigate the effects of housing (deep litter + concrete floor vs. deep litter + ground soil with the possibility to dig burrows), and genotype (Mecklenburg or Hyplus) on aggressive behaviour, social contacts, does’ and kits’ injuries, and progeny mortality. Twelve groups of six rabbit does (n = 72) were assigned to four treatments (two housing systems and two genotypes). Aggressive behaviour of does, number of injuries on does and kits, and postnatal kit mortality were recorded. The effects of housing and genotype were tested using multivariate GLMM Models. We found that the housing treatment in interaction with the genotype had a significant effect on aggressive behaviours in group housed does (F3,12 = 14.34, p = 0.0003), where the lowest incidence of aggression was in Mecklenburg does housed on ground soil. Reduced aggression was reflected in a lower number of injuries in does (F3,68 = 10.51, p < 0.0001), number of injuries in kits, and kit mortality (F3,1 = 4.59, p < 0.0001, F3,54 = 43.94, p < 0.0001). The results indicate that the proper combination of genotype and housing should be carefully considered for breeding to reduce aggression and injury in group housed does.