Locomotion scoring is a useful tool as part of a routine herd health evaluation or in a detailed herd lameness investigation.
Most farmers will detect between only 25% and 40% of truly lame cows; this underestimation of lameness prevalence means that the economic consequences of lame cows are less obvious to farmers than those caused by mastitis (loss of milk) and fertility problems. Cows in the early stages of sole ulcer, white line disease, and toe necrosis syndrome show only slight signs of lameness; if these lesions can be identified in their early stages, they can be treated and preventive measures instituted.
Locomotion scoring identifies slightly lame cows as well as those more obviously lame. Therefore, use of locomotion scoring can demonstrate the real extent of the problem.
Herd assessments should be done when the cows are walking on level, unobstructed walkways that give the observer a clear view. Locomotion scoring is frequently performed when the cows are leaving the milking parlor. In addition, milkers should note any cow standing in the milking parlor with an arched back, because it is highly probable that such cows are lame. Any cow lying down for an abnormally long time (>70–80 min/bout) should also be noted for special attention.
Locomotion scoring is a 5-point system based on both gait and posture: 1) Normal: The cow is not lame; the back is flat. 2) Mildly lame: The back is slightly arched when walking. 3) Moderately lame: The back is arched when both standing and walking. The cow walks with short strides in one or more legs. 4) Lame: The lame cow can still bear some weight on the affected foot. 5) Severely lame: The back is arched; the cow refuses to bear weight on the affected foot and remains recumbent. (Some observers use a 4-point scoring system, referring to normal as zero.) The repeatability of locomotion scoring is acceptably high among experienced observers.
As the locomotion score increases, milk yield decreases; however, the composition of the milk (fat, protein) remains unaffected.