Assessment of dairy cow locomotion in a commercial farm setting: The effects of walking speed on ground reaction forces and temporal and linear stride characteristics A.M. Walker a, * , T. Pfau b , A. Channon d , A. Wilson c a Structure and Motion Lab., Department of Veterinary Basic Sciences, The Royal Veterinary College, Hatfield, Herts AL9 7TA, United Kingdom b Department of Veterinary Clinical Sciences, Royal Veterinary College, United Kingdom c Department of Veterinary Basic Sciences, Royal Veterinary College, United Kingdom d Department of Human Anatomy and Cell Biology, University of Liverpool, Liverpool L69 3GE, United Kingdom article info Article history: Accepted 12 May 2009 Keywords: Forces Speed Walking Biomechanics Cow abstract Objectives of this study were to determine the effects of walking speed on ground reaction force (GRF) parameters and to explore inter- and intra-individual variability with unsupervised data collection in a commercial farm setting. We used eight high producing loose-housed Holstein Friesian cows consistently scored sound, with no veterinary treatment during the collection period. Cows walked freely (0.52–1.37 m/s) over a five force platform array, twice daily, following milking. GRF data were split into speed categories and temporal and kinetic gait parameters extracted. A general linear model was carried out to determine effects of speed. Variation in parameters between cows is inconsistent, while between speed categories (containing data from multiple cows) the parameters which vary are consistent. Stance and stride time were reduced with increasing speed but no change in peak vertical GRF or duty factor was found. This ability to track param- eters within an individual over time aids detection of subtle changes associated with lameness. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Intensive farming and selective breeding for high yielding milk traits have influenced the prevalence of lameness in dairy herds increasing from 21% found in a study from 1989 to 1991 (Clarkson et al., 1996) to 21.1% in summer and 23.9% in the winter of 2000/ 2001 (Cook, 2003) before reaching 25% in 2004 (Espejo et al., 2006). The incidence of lameness was found to increase from 5.5% in 1977 (Russell et al., 1982) to 25% in 1983 (Whitaker et al., 1983) and to 55% in 1991 (Clarkson et al., 1996). These studies in- cluded herds of different sizes from UK and USA farms. The two most recent studies were conducted on USA farms which may have different husbandry techniques and stocking densities. This com- bined with the effect of increased awareness and improved docu- mentation of lameness in recent years could be accountable for some of the increases noted. These figures are not representative of worldwide prevalence but lameness is a major problem world- wide. High annual incidence of lameness has economic as well as welfare implications within the dairy industry causing large finan- cial losses from reduced milk yield which are exacerbated by in- creased culling (Whitaker et al., 1983; Warnick et al., 2001). The use of objective methods (in place of subjective locomotion scoring) enables detailed analysis of changes in gait due to many factors including pre and post milking (Flower et al., 2006), hoof pathologies (Flower et al., 2005), and claw trimming (van der Tol et al., 2004). Objective analysis helps identify which parameters in sound cows undergo changes with speed. This allows determi- nation of baseline data for comparison with dairy cows of varying degrees of lameness. Descriptive details such as the range of vari- ation of GRF (ground reaction force) parameters (observed in a commercial farm setting) and the effects of speed on locomotor parameters are of great importance to further our knowledge about ‘normal’ gait and as a result to inform future studies into lameness related changes. Objective assessments of gait parameters in cows showing no visual signs of lameness or claw disorders have been made with the cows standing on (van der Tol et al., 2002, 2004), or walking over a pressure plate (van der Tol et al., 2003). Other studies have consisted of retrospective observations involving milk yield (Green et al., 2002; Warnick et al., 2001; Hernandez et al., 2005), calving to conception intervals (Hernandez et al., 2001), effects of lameness on culling and the effects of hoof trimming on lameness (O’Calla- ghan Lowe et al., 2004; van der Tol et al., 2004; Zeiner et al., 2007). Vertical GRF in cows have been investigated (Scott, 1988; van der Tol et al., 2003), but these data do not present detailed 0034-5288/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.rvsc.2009.05.016 * Corresponding author. Tel.: +44 0 1707 666425; fax: +44 0 1707 666371. E-mail address: amwalker@rvc.ac.uk (A.M. Walker). Research in Veterinary Science 88 (2010) 179–187 Contents lists available at ScienceDirect Research in Veterinary Science journal homepage: www.elsevier.com/locate/rvsc