Conte S, Bergeron R, Gonyou H, Brown J, Rioja-Lang F C, Connor L, Devillers N
Agriculture and Agri-Food Canada, Dairy and Swine R&D Centre, Sherbrooke, Canada.
University of Guelph, Alfred Campus, Alfred, Canada.
J Anim Sci. 2014 Dec;92(12):5693-703. doi: 10.2527/jas.2014-7865. Epub 2014 Nov 17.
The objective was to assess sows' lameness by measuring weight distribution on limbs using a force plate made up of 4 individual platforms each resting on 4 single-ended beam load cells. The weight was recorded at an average rate of 14 readings per s over a 15 min period. Ten sows (5 lame sows and 5 sound sows) were weighed twice on 2 different days to assess the repeatability of the measure. Sixty-one sows were then selected in 2 different sites and visually scored for lameness, using a 3-point scoring system (0=normal gait; 1=abnormal gait, and/or stiffness; and 2=shortened stride, and/or the sow puts less weight or avoids putting weight on 1 leg). Various measures were recorded from each sow using the force plate (percentage of weight, the ratio between the weights applied by contralateral legs, weight shifting, and amplitude of weight bearing and weight removing), kinematics (speed, stride length, swing time, stance time, foot height, and carpal and tarsal joints angle average and amplitude), and accelerometers (time spent standing during 24 h, frequency of stepping behavior during feeding, and latency to lie down after feed delivery). The within-sow CV for each measure taken from the force plate were lower than 15%, which reflects a good repeatability. Among force plate measures, only the weight shifting frequency and the ratio between the weights applied by contralateral legs differed between lameness scores. Sows that scored 2 had a higher frequency of weight shifting for fore legs (P=0.0003) and hind legs (P=0.0007) than sows scored 0 and 1. The ratio between the weights applied by contralateral legs decreased with the increase of lameness score for the hind limbs (P=0.014). However, these measures also differed between sites (P<0.01). These differences may be due to various reasons, including but not limited to genetics and housing systems. Nevertheless, the results suggest that force plate measures such as the asymmetry in the weight applied between a pair of legs and weight shifting are good indicators of lameness. Multivariate analysis on fore and hind legs showed independency between variables related to animals in movement (measures from kinematics) and variables related to static animals (measures from the force plate and accelerometers). Therefore, both static and dynamic methods need to be used to detect various lame sows.
目的是通过使用由4个独立平台组成的测力板来测量母猪四肢的重量分布，每个平台均放置在4个单端梁式称重传感器上，以此评估母猪的跛行情况。在15分钟内，以每秒14次读数的平均速率记录重量。10头母猪（5头跛行母猪和5头健康母猪）在2个不同日期称重两次，以评估该测量方法的可重复性。然后在2个不同地点挑选61头母猪，使用3分制评分系统对跛行情况进行视觉评分（0 =正常步态；1 =异常步态和/或僵硬；2 =步幅缩短，和/或母猪在一条腿上施加的重量减轻或避免在该腿上施加重量）。使用测力板记录每头母猪的各种测量数据（重量百分比、对侧腿施加重量的比率、重量转移以及承重和卸重的幅度）、运动学数据（速度、步幅长度、摆动时间、站立时间、蹄部高度以及腕关节和跗关节角度的平均值和幅度）以及加速度计数据（24小时内站立时间、进食期间的踏步行为频率以及喂食后躺下的潜伏期）。从测力板获取的每项测量数据的母猪内变异系数均低于15%，这反映出良好的可重复性。在测力板测量数据中，只有重量转移频率和对侧腿施加重量的比率在跛行评分之间存在差异。评分为2的母猪前腿（P = 0.0003）和后腿（P = 0.0007）的重量转移频率高于评分为0和1的母猪。后肢对侧腿施加重量的比率随着跛行评分的增加而降低（P = 0.014）。然而，这些测量数据在不同地点之间也存在差异（P < 0.01）。这些差异可能有多种原因，包括但不限于遗传因素和饲养系统。尽管如此，结果表明测力板测量数据，如一对腿之间施加重量的不对称性和重量转移，是跛行的良好指标。对前腿和后腿的多变量分析表明，与运动中动物相关的变量（运动学测量数据）和与静止动物相关的变量（测力板和加速度计测量数据）之间相互独立。因此，需要同时使用静态和动态方法来检测各种跛行母猪。
