PubAg

Main content area

Technical note: The development of a reliable 5-point gait scoring system for use in dairy goats

Author:
Deeming, L.E., Beausoleil, N.J., Stafford, K.J., Webster, J.R., Zobel, G.
Source:
Journal of dairy science 2018 v.101 no.5 pp. 4491-4497
ISSN:
0022-0302
Subject:
Saanen, dairy farming, dairy goats, gait, lactation, lameness, rating scales
Abstract:
Numerical rating scales are frequently used in gait scoring systems as indicators of lameness in dairy animals. The gait scoring systems commonly used in dairy goats are based on 4-point scales that focus on detecting and judging the severity of a definite limp. An uneven gait, such as a shortened stride or not “tracking up,” is arguably the precursor to the development of a limp; thus, identifying such changes in gait could provide opportunity for early treatment. The objectives of this study were (1) to develop a 5-point gait scoring system that included an “uneven gait” category and compare the distribution of gait scores generated using this system to scores generated using a 4-point system, and (2) to determine whether this system could be reliably used. Forty-eight Saanen cross 2- and 3-yr-old lactating does were enrolled from a commercial dairy goat farm. Two observers carried out weekly live gait scoring sessions for 7 wk using the developed 5-point scoring system. The first 2 wk were used as training sessions (training sessions 1–2), with the subsequent 5 wk completed as gait assessments (assessments 1–5). In addition to training session 1 being lived scored, the goats were also video-recorded. This allowed observer 1 to re-score the session 4 times: twice using the developed 5-point system and twice using the previously used 4-point system. Comparisons of score distributions could then be made. Using the 4-point system, 81% of the goats were assigned score 1 (normal gait). Using the 5-point system, only 36% of the goats were assigned score 1 (normal gait), with 50% assigned score 2 (uneven gait). High levels of intra-observer reliability were achieved by observer 1 using both gait scoring systems [weighted kappa (κw) = 1.00: 4-point, κw = 0.96: 5-point]. At training session 1 (wk 1), inter-observer reliability was only moderate (κw = 0.54), but this was improved during the subsequent training session 2 (κw = 0.89). Inter-observer reliability was high among assessments 1 to 5 (κw = 0.90–1.00). During the training sessions, sensitivity for gait scores 1 and 2 was 77 and 65% (training session 1) and 89 and 94% (training session 2), respectively. Sensitivity was high among assessments 1 to 5 (score 1: 83–100%, score 2: 97–100%). This highlights the likely reason why existing gait scoring systems for dairy goats do not include an “uneven gait” category, as distinguishing it from a normal gait was challenging without training. In conclusion, with training, a 5-point gait scoring system could be reliably used. The 5-point system was found to be more sensitive than the 4-point system, allowing for a potential precursor to lameness to be identified. Further work is needed to determine whether the score can be reliably used in an on-farm setting.
Agid:
5933221