KINEMATIC STUDY OF THE LOCOMOTION OF 2 CROSSBREDS OF LAMBS

In the present study we suggest the use of kinematics for measuring lo comotive abilities of two lamb crossbreds, bred for meat production (B errichons and BMC), facing three environmental conditions: walking on a regular mud floor, walking on a stony ground and jumping from an uph ill slope. In order to observe their locomotive strategy, animals were free to move around. Classical kinematic analysis was modified in rel ationship to the experimental context. Spatial and temporal data (stri de length and duration, time interval between footfalls of limbs, ampl itude of angular variations of articular segments) were collected to q uantify motor coordination and limb posture, The BMC spontaneously ado pted a more extensive scale of gaits with lateral sequences, they also used a wider range of speeds (0.8-2.5 m/s) with larger stride length (0.82 m) on the regular floor. On the stony ground, both breeds adapte d their gaits in the same way, walking slowly (0.5-1.2 m/s). A large b ehavioural difference appeared between both breeds during the approach phase of the jump. For example, Berrichons slowed down and adjusted t he feet position before jumping. Conversely, BMC showed the greatest m anoeuverability as regards the obstacle. This study shows a difference in locomotive stategies between breeds according to the exercice. It underlines a better ability of BMC to walk in the varying conditions t hat characterise extensive grassland. Thus, the data of kinematic anal ysis should be used as an indicator for the selection of production an imals.