Department of Comparative Biomedical Science, School of Veterinary Medicine, Teramo, Italy.
Physiol Behav. 2013 Jan 17;109:8-13. doi: 10.1016/j.physbeh.2012.11.006. Epub 2012 Nov 30.
The conflicting results regarding the study of motor laterality in horses may indicate that there does not exist a proper method to assess the degree and the direction of motor bias in these animals. Unfortunately, even less is known about the development of laterality in horses, and to what extent early manipulations can still exert their effects in adulthood. We propose a new method that can be easily applied at a very early age thus avoiding testing adult horses eventually biased by human handling and/or training. Forty-six horses (29 nine-month-old foals and 17 two-year old horses) were handled since birth bilaterally and housed in groups in wide areas. At the time of the analysis, in order to minimize environmental and sensorial disturbances, each horse was tested in a round pen individually or as dyad mother-foal. The ability/inability to properly execute a circle at trot was then recorded, assuming the direction of derailment, i.e. the cutting of the circle, as an indicator of motor bias. From the results of the study it is arguable that motor laterality in horses is acquired over time: in fact foals tested while their mothers were being subjected to longeing showed a higher percentage of ambidextrous animals, while two-year-old horses appeared biased toward the right (p<0.05). Results are discussed in the light of the scientific knowledge about equine biomechanics, taking into account horses' locomotion that leads to the advancement of the body mass through the activation of a kinetic chain that originates from the hindquarters.
关于马的运动偏侧性的研究结果相互矛盾，这可能表明目前还没有一种合适的方法来评估这些动物的运动偏侧程度和方向。不幸的是，人们对马的偏侧性发展知之甚少，也不知道早期的操作在多大程度上仍然会在成年期发挥作用。我们提出了一种新的方法，这种方法可以在非常早期就很容易地应用，从而避免对最终受到人类操作和/或训练影响的成年马进行测试。46 匹马（29 匹 9 个月大的驹和 17 匹 2 岁的马）从出生起就接受双侧处理，并被安置在宽敞的区域内成群饲养。在分析时，为了将环境和感官干扰最小化，每匹马都在圆形围栏中单独或以母子对的形式进行测试。然后记录它们在小跑时是否能够正确地完成一个圆圈，假设偏离的方向，即圆圈的切割，作为运动偏侧性的指标。从研究结果来看，可以认为马的运动偏侧性是随着时间的推移而获得的：事实上，当它们的母亲被进行调教时，驹被测试，表现出更多的是左右均衡的动物，而 2 岁的马则表现出右偏（p<0.05）。结果是根据马的生物力学科学知识进行讨论的，考虑到马的运动，即通过激活起源于后躯的动力链，使身体质量向前推进。
