Animal Sciences Unit, ILVO, Scheldeweg 68, 9090 Melle, Belgium; Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Animal Sciences Unit, ILVO, Scheldeweg 68, 9090 Melle, Belgium.
Animal. 2023 Jun;17(6):100850. doi: 10.1016/j.animal.2023.100850. Epub 2023 May 10.
Housing of breeding does in group pens can result in skin injuries and stress due to maternal protective behaviour and hierarchy fights. Aggression can be partly reduced by using single-litter cages during the first weeks of the reproductive cycle and by delaying the grouping of does with their litters until the kits are older. Hierarchy fights do still occur in these part-time housing systems, however. The present study evaluated the effect of group size and cage enrichment on doe and kit skin injuries and on doe social behaviour. During four cycles, groups of either three or four does with their 22-day-old kits were housed in group pens for 13 days. Pens were assigned one of the following treatments (n = 12 pens per treatment): group of four does with no additional enrichment, four does with additional cage enrichment, three does with no additional enrichment and three does with additional cage enrichment. Cage enrichment was comprised of plastic pipes and elevated platforms. As pen size remained constant, a change in group size also implied a proportional change in stocking density. The number and severity of skin injuries were monitored before grouping and at 1, 3, 6, 9 and 13 days after grouping. Video recordings from all group pens were scored continuously for doe behaviour during the first 24 h after grouping in the first and second reproduction cycle and for the first 8 h in the third cycle. Four severely injured does needed to be removed after grouping. During the first day after group housing, respectively, 72.6 and 13.0% of the does and kits acquired at least one new skin injury with respect to the onset of group housing. Compared with groups of four, does in groups of three had lower averaged skin injury scores (9.41 versus 8.40, P = 0.004). Of all observed postgrouping social behaviours, submissive behaviour was most frequently observed (42.8%), followed by aggressive behaviour (29.8%), engaging behaviour (25.1%) and non-aggressive social contact (2.3%). Does used the enrichment during 11.1% of the total observation time, during which the platforms were more frequently visited (97.2%) in comparison to the plastic pipes (2.8%). As shown by the percentage of injured animals on the last day of grouping (does: 61.9% and kits: 18.4%), postgrouping aggression remains a problem that appears difficult to reduce to acceptable levels by reducing group size (and stocking density) or by providing cage enrichment.
繁殖用的母猪饲养在群体围栏中可能会导致皮肤损伤和压力，这是由于母性行为和等级斗争。通过在繁殖周期的前几周使用单窝笼，并在幼崽稍大些时再将母猪与其幼崽分组，可以部分减少攻击性。然而，在这些兼职饲养系统中，等级斗争仍然会发生。本研究评估了群体大小和笼内丰富度对母猪和幼崽皮肤损伤以及母猪社会行为的影响。在四个周期中，将 22 天大的幼崽与 3 或 4 头母猪一起饲养在群体围栏中 13 天。围栏被分配到以下处理之一（每个处理 12 个围栏）：没有额外丰富度的 4 头母猪群体、有额外笼内丰富度的 4 头母猪群体、没有额外丰富度的 3 头母猪群体和有额外笼内丰富度的 3 头母猪群体。笼内丰富度由塑料管道和高架平台组成。由于围栏大小保持不变，群体大小的变化也意味着饲养密度的比例变化。在分组前和分组后 1、3、6、9 和 13 天监测皮肤损伤的数量和严重程度。在第一和第二个繁殖周期的分组后 24 小时内以及第三个周期的前 8 小时内，对所有群体围栏的视频记录进行连续评分，以记录母猪行为。分组后，有 4 头严重受伤的母猪需要被移除。分别在群体饲养后的第一天，69.6%和 13.0%的母猪和幼崽在群体饲养后出现了至少一个新的皮肤损伤。与 4 头母猪相比，3 头母猪的平均皮肤损伤评分较低（9.41 对 8.40，P=0.004）。在所有观察到的分组后社会行为中，最常见的是顺从行为（42.8%），其次是攻击行为（29.8%）、参与行为（25.1%）和非攻击性社会接触（2.3%）。母猪在总观察时间的 11.1%期间使用了丰富度，在此期间，平台的访问频率更高（97.2%），而塑料管道的访问频率更低（2.8%）。从分组的最后一天受伤动物的百分比（母猪：61.9%和幼崽：18.4%）可以看出，分组后的攻击性仍然是一个问题，通过减少群体大小（和饲养密度）或提供笼内丰富度似乎难以将其降低到可接受的水平。
