Assessment of lameness in sows using gait, footprints, postural behaviour and foot lesion analysis

Abstract

Lameness in sows has an economic impact on pig production and is a major welfare concern. The aim of the present project was to develop methods to evaluate and quantify lameness in breeding sows. Five methods to study lameness were compared between themselves and with visual gait scoring used as a reference: footprint analysis, kinematics, accelerometers, lying-tostanding transition and foot lesion observation. Fifty sows of various parities and stages of gestation were selected using visual gait scoring and distributed into three groups: lame (L), mildly lame (ML) and non-lame (NL). They were then tested using each method. Kinematics showed that L sows had a lower walking speed than NL sows (L: 0.83 6 0.04, NL: 0.96 6 0.03 m/s; P , 0.05), a shorter stride length than ML sows (L: 93.0 6 2.6, ML: 101.2 6 1.5 cm; P , 0.05) and a longer stance time than ML and NL sows (L: 0.83 6 0.03, ML: 0.70 6 0.03, NL: 0.69 6 0.02 s; P , 0.01). Accelerometer measurements revealed that L sows spent less time standing over a 24-h period (L: 6.3 6 1.3, ML: 13.7 6 2.4, NL: 14.5 6 2.4%; P , 0.01), lay down earlier after feeding (L: 33.4 6 4.6, ML: 41.7 6 3.1, NL: 48.6 6 2.9 min; P , 0.05) and tended to step more often during the hour following feeding (L: 10.1 6 2.0, ML: 6.1 6 0.5, NL: 5.4 6 0.4 step/min standing; P 5 0.06) than NL sows, with the ML sows having intermediate values. Visual observation of back posture showed that 64% of L sows had an arched back, compared with only 14% in NL sows (P 5 0.02). Finally, footprint analysis and observation of lying-to-standing transition and foot lesions were not successful in detecting significant differences between L, ML and NL sows. In conclusion, several quantitative variables obtained from kinematics and accelerometers proved to be successful in identifying reliable indicators of lameness in sows. Further work is needed to relate these indicators with causes of lameness and to develop methods that can be implemented on the farm.

On-farm evaluation of methods to assess welfare of gestating sows

“…during feeding) can indicate a lame animal that is transferring weight from a weak leg to another leg (Grégoire et al, 2013). However, no associations were observed in the present study between stepping and gait-score categories, but this may be related to the data collection method.…”

“…Comparison of lameness measures and associations with housing, stage of gestation and parity Using automated methods such as kinematics, Grégoire et al (2013) demonstrated that lame animals had reduced stride length and walking speed compared with sound animals. It was suggested that this reduction in speed and stride length was a way to reduce pain by decreasing the load on the affected leg.…”

“…For instance, postural behaviour which could be used as an indicator of lameness can also be affected by space allowance (Salak-Johnson et al, 2012). Other lameness measures such as sow walking speed, stride length and stepping behaviour have been shown to be promising quantitative indicators of lameness and may be easily measured on farm (Ringgenberg et al, 2010;Grégoire et al, 2013). Recording the presence of stereotyped behaviours requires the performance of animal observations, which can disturb the sow and interrupt the abnormal behaviour (Keeling, 2009).…”

“…Recording the presence of saliva foam around the mouth has been suggested as an alternative (Fraser and Broom, 1990). Finally, most of the work on development of methods to assess sow reactivity to humans or lameness was done under experimental conditions without being validated under commercial conditions (Clouard et al, 2011;Grégoire et al, 2013). Therefore, the objectives of this study were to evaluate under commercial conditions several indicators related to three components of sow welfare (sow lameness, oral stereotypies and reactivity to humans) and to determine whether or not rearing conditions, sow parity and stage of gestation might affect these indicators.…”

Effect of locomotion score on sows’ performances in a feed reward collection test

“…The occurrence and severity of lameness can be determined by several methods such as visual inspection of the gait (Main et al, 2000;Nalon et al, 2014) and using kinematic techniques like pressure mats and accelerometers (Grégoire et al, 2013;Pluym et al, 2013b;Meijer et al, 2014). However, none of these methods directly evaluates the effects of lameness on the capability of locomotion.…”