1 Changes in Kinematic Measurements from Nursery through Finishing for a Mixed Group of Pigs.

The objective of this study was to isolate measurements in young pigs and monitor changes as the pigs grew. These values might be able to help pinpoint lameness prone animals and allow for their removal from the herd. Twenty-seven True Choice Genetics pigs (CG32xEB5 (9 females, 6 males) and G32 x EBX (6 females, 5 males) were randomly selected prior to 23 kg to evaluate changes in gait as pigs grow. Pigs were individually walked across a 7.5 m pressure mat (GAIT4Dog®) at 23, 45, 68, 91, 113 and 136 kg for 6 repetitions at each weight. Stance time, swing time, stride length, percent stance, gait cycle, and velocity were recorded and analyzed using SAS 9.4 PROC MIXED repeated measures model. Velocity decreased as pigs grew, (P < 0.03). There was an increase from 23 to 136 kg in cycle time for both the front and back legs (P < 0.0011). Stride length (P < 0.001), swing time (P < 0.001) and stance time (P < 0.001) both increased as the animals aged. Percent stance for both front and rear legs increased as the animal aged (P < 0.001). Compared to males, females had an increased velocity (P < 0.001), decreased cycle time (P < 0.001), increased stride length (P < 0.001), decreased stance time (P < 0.001) and decreased percent stance (P < 0.001). Compared to the EB5 sired pigs, the EBX sired pigs had increased velocity (P < 0.002), increased cycle time (front P < 0.03; rear P < 0.06), increased stride length (P < 0.001), increased swing time (P < 0.001), and decreased percent stance (front P< 0.01; rear P < 0.001). These data indicate that the gait of pigs changes with growth and there are differences in the gait due to sex and sire line. Velocity (cm/s) 23 kg 136 kg Female Male EB5 EBX 184.89 180.93 192.75 178.83 181.56 190.03 Front Swing (s) 0.21 0.23 0.23 0.23 0.22 0.23 Stance (s) 0.16 0.29 0.22 0.25 0.24 0.24 Stride Length (cm) 67.67 91.60 84.29 81.70 80.47 85.52 Percent Stance (%) 43.37 54.64 48.48 50.63 50.00 49.11 Rear Swing (s) 0.23 0.26 0.25 0.25 0.24 0.26 Stance (s) 0.14 0.27 0.20 0.22 0.22 0.21 Stride Length (cm) 67.66 91.14 84.01 81.48 80.28 85.22 Percent Stance (%) 37.14 49.78 44.06 45.28 45.83 43.50 Least square means of gait parameters for beginning and end weights, sex and sire lines [ABSTRACT FROM AUTHOR]