Baumgartner Miriam, Erhard Michael H, Zeitler-Feicht Margit H
Agroscope, Swiss National Stud Farm, SNSTF, Avenches, Switzerland.
Department of Veterinary Sciences, Faculty of Veterinary Medicine, Animal Hygiene and Animal Husbandry, Chair of Animal Welfare, Ethology, Ludwig-Maximilians-University Munich, Munich, Germany.
Front Vet Sci. 2023 Jan 9;9:1005102. doi: 10.3389/fvets.2022.1005102. eCollection 2022.
Automated feeding systems offer numerous advantages for animals and humans, but the associated benefits and risks can often only be seen under practical conditions. The space allowance (~80 cm per horse) at time-controlled hay racks for horses in group housing, unlike at partitioned feeding stands or transponder-controlled feed stations, currently falls below the required individual distance between the horses, which can result in a high level of aggression between the horses due to the lack of partitions between them. Hence, a feed-through at a time-controlled hay rack cannot be equated with a feeding place. In this preliminary study, we therefore aimed to determine the minimum animal-to-feeding-place ratio (AFR) at time-controlled hay racks that would provide adequate individual distances between the horses.
To do so, we assessed behavioral and physiological parameters (via video behavioral observations and salivary cortisol measurements) of up to 28 horses in a loose housing system. Over 2 observation days per treatment, four AFRs were investigated in a balanced sequence: 1:1.2, 1:2, 1:3, and C (single feeding in familiar surroundings as a control).
We found that the horses expressed less aggressive behavior, especially those behaviors with a high risk of injury such as biting and kicking, when there were three times as many openings as there were horses at time-controlled hay racks, as compared with only 20% more openings or twice as many openings as there were horses [lineal mixed model: = 7.411; adjusted = 0.733; = 0.06, = 0.02, = 0.01]. The salivary cortisol levels during feeding decreased more strongly with more generous AFRs [ = 0.02]. The factors hierarchy and individual showed no influence. In contrast, the day of the experiment and the associated weather conditions, despite randomized selection, influenced both the behavioral and the physiological parameters.
The results of this preliminary study indicate that the investigated time-controlled hay racks must provide at least three times as many feeding places as there are horses to ensure that neighboring horses can keep their individual distance and stress-free feeding is possible. Further studies on more farms and different types as well as arrangement of hay racks are proposed.
自动饲喂系统对动物和人类有诸多益处，但相关的好处和风险通常只有在实际条件下才能显现。与分隔式饲喂架或应答器控制的饲喂站不同，群居马匹的定时干草架处的空间允许量（每匹马约80厘米）目前低于马匹之间所需的个体间距，这可能导致马匹之间因缺乏分隔而产生高度攻击性。因此，定时干草架处的穿行式饲喂不能等同于一个饲喂场所。在这项初步研究中，我们旨在确定定时干草架处能为马匹提供足够个体间距的最小动物与饲喂场所比例（AFR）。
为此，我们在一个宽松的饲养系统中评估了多达28匹马的行为和生理参数（通过视频行为观察和唾液皮质醇测量）。在每个处理的2个观察日中，按平衡顺序研究了四个AFR：1:1.2、1:2、1:3和C（在熟悉环境中的单独饲喂作为对照）。
我们发现，当定时干草架处的开口数量是马匹数量的三倍时，马匹表现出的攻击性行为较少，尤其是那些有高受伤风险的行为，如咬和踢，而开口数量仅比马匹数量多20%或开口数量是马匹数量的两倍时则不然[线性混合模型： = 7.411；调整后 = 0.733； = 0.06， = 0.02， = 0.01]。随着AFR更宽松，饲喂期间的唾液皮质醇水平下降得更明显[ = 0.02]。因素等级和个体没有影响。相比之下，尽管是随机选择，但实验日和相关天气条件对行为和生理参数都有影响。
这项初步研究的结果表明，所研究的定时干草架必须提供至少三倍于马匹数量的饲喂场所，以确保相邻马匹能够保持个体间距并实现无压力饲喂。建议在更多农场以及不同类型和布置的干草架上进行进一步研究。
