Invited review Aspects of lameness in pasture based dairy systems Alexandra Hund a , Joaquin Chiozza Logroño b , Rudiger Daniel Ollhoff c , Johann Kofler a, * a Department of Farm Animals and Veterinary Public Health, University Clinic for Ruminants, University of Veterinary Medicine Vienna, 1210 Vienna, Austria b CONICET, Godoy Cruz 2290, CABA, Argentina & Cátedra y Servicio de Reproducción Animal, FCV-UNLP, La Plata, BA, Argentina c Programa de Pós-Graduação em Ciência Animal, Escola de Ciências da Vida, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil A R T I C L E I N F O Article history: Accepted 7 December 2018 Keywords: Cattle Cow Grazing Lameness Claw lesions Prevalence Risk factors A B S T R A C T Pasture-based dairy systems are implemented all over the world. Access to pasture is perceived to be advantageous for animal welfare in western societies. However, the benefits of grazing on lameness are not uniformly verifiable. This is related to the challenges that grazing cows face which are different from zero-grazing systems to some extent, but may nevertheless be deleterious. The distribution of lesion types comparing housed and pastured cattle differs between studies. This may be caused by differences in how strongly certain risk factors apply in these studies. Major risk factors for lameness in grazing cattle are related to the risk of trauma, for example from long walking distances and lack of track maintenance, and cow factors such as the adaptability of certain breeds to the grazing lifestyle. The consequences of lameness are similar to zero-grazing cattle and negatively affect animal welfare and productivity. © 2018 Elsevier Ltd. All rights reserved. Introduction In many countries with favourable climatic conditions, pro- ducers can resort to pasture-based dairy systems. However, systems in which cows are housed throughout the year (zero- grazing) are practised in many parts of the world to control diet and optimize grassland utilization (Van den Pol-van Dasselaar et al., 2008). At the same time, there is an increasing cultural demand that cows have access to open air, preferably pasture, since this permits cows to exhibit normal behaviour, which in turn increases animal health and welfare. There is a prevailing perception that grazing cattle are less affected by lameness. Lameness is defined as an abnormal gait that is most commonly caused by pain (Whay and Shearer, 2017). Therefore, it is one of the most important welfare indicators in cattle (Arnott et al., 2017). However, grazing can compromise other aspects of animal welfare, such as freedom from hunger and discomfort. 1 In inclement or hot weather, cows prefer to be indoors (Legrand et al., 2009; Charlton et al., 2011), but shelter is not necessarily provided in many grazing systems. Further, high-yielding dairy cows on pasture might not be able to meet their nutritional requirements exclusively from grazing and therefore lose body weight and produce less milk (Hernandez-Mendo et al., 2007). Milk output per cow, however, is directly linked to the environmental sustainability of dairy operations (Chen et al., 2016). Aside from meeting consumer expectations, the use of pasture has many advantages. When given the choice, cows prefer pasture at night over free-stall housing during grazing season. The partial preference to be indoors could be triggered by a need to meet nutritional requirements with the total mixed ration (TMR) being provided indoors, and unfamiliarity with pasture (Legrand et al., 2009; Charlton et al., 2011). If cows have experience of the outdoors they chose to spend most of their time on pasture, unless there is inclement weather, and prefer fresh forage over haylage (Shepley et al., 2017). Unlike pasture, hard surfaces do not permit normal locomotory behaviour, partially due to a lack of friction. When the coefficient of friction at the claw–floor interface is lower than that needed to perform movement, slipping occurs. Indeed, concrete floors provide coefficients of friction that range from 0.25 to 0.54, which are sufficient for straight line walking, but not for sudden starts and stops (van der Tol et al., 2005). For unrestrained locomotion a coefficient of friction of more than 0.6 is required for dairy cattle (van der Tol et al., 2005) and that of pasture is higher than 0.8 (Telezhenko et al., 2004). Therefore pasture provides optimal locomotory comfort to cows (Alsaaod et al., 2017), a more comfortable surface to stand and lie down on (Higashiyama et al., 2013), and has been shown to help cattle improve lameness scores, possibly facilitating the recovery from claw and leg injuries (Hernandez-Mendo et al., 2007). * Corresponding author. E-mail address: Johann.Kofler@vetmeduni.ac.at (J. Kofler). 1 See: FAWC, 2009. Five Freedoms. http://webarchive.nationalarchives.gov.uk/ 20121003015231/http://www.defra.gov.uk/fawc/about/five-freedoms/. (Accessed 16 November 2017). https://doi.org/10.1016/j.tvjl.2018.12.011 1090-0233/© 2018 Elsevier Ltd. All rights reserved. The Veterinary Journal 244 (2019) 83–90 Contents lists available at ScienceDirect The Veterinary Journal journal homepage: www.else vie r.com/locate /t vjl