Predictive models of lameness in dairy cows achieve high sensitivity and specificity with force measurements in three dimensions.
Lameness remains a significant cause of production losses, a growing welfare concern and may be a greater economic burden than clinical mastitis . A growing need for accurate, continuous automated detection systems continues because US prevalence of lameness is 12.5% while individual herds may experience prevalence's of 27.8-50.8%. To that end the first force-plate system restricted to the vertical dimension identified lame cows with 85% specificity and 52% sensitivity. These results lead to the hypothesis that addition of transverse and longitudinal dimensions could improve sensitivity of lameness detection. To address the hypothesis we upgraded the original force plate system to measure ground reaction forces (GRFs) across three directions. GRFs and locomotion scores were generated from randomly selected cows and logistic regression was used to develop a model that characterised relationships of locomotion scores to the GRFs. This preliminary study showed 76 variables across 3 dimensions produced a model with greater than 90% sensitivity, specificity, and area under the receiver operating curve (AUC). The result was a marked improvement on the 52% sensitivity, and 85% specificity previously observed with the 1 dimensional model or the 45% sensitivities reported with visual observations. Validation of model accuracy continues with the goal to finalise accurate automated methods of lameness detection.
Department of Mechanical Engineering,University of Maryland Baltimore County,Baltimore,MD 21250,USA.
Jason
J
Dunthorn
Department of Animal and Food Sciences,College of Agriculture and Natural Resources,University of Delaware,Newark,DE 19717,USA.
Robert M
RM
Dyer
Department of Mathematics and Statistics,University of Maryland at Baltimore County,Baltimore,MD 21250,USA.
Nagaraj K
NK
Neerchal
Department of Mathematics and Statistics,University of Maryland at Baltimore County,Baltimore,MD 21250,USA.
Jonathan S
JS
McHenry
BouMatic LLC,1919 South Stoughton Road,Madison,WI 53716,USA.
Parimal G
PG
Rajkondawar
BouMatic LLC,1919 South Stoughton Road,Madison,WI 53716,USA.
Gary
G
Steingraber
StepAnalysis LLC,5 Ruby Field Court,Baltimore,MD 21209,USA.
Uri
U
Tasch
D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D005260:Female; D007794:Lameness, Animal / Q000175:diagnosis*; D008954:Models, Biological; D009043:Motor Activity; D011312:Pressure; D012680:Sensitivity and Specificity
3 orthogonal dimensions; Lameness; detection; force plate