Biomechanics of the bovine foot

Lameness is one of the most important problems in modern dairy husbandry (Winckler and Brill, 2004; Barker et al. 2010; Hilger and Passarge, 2018), which is mainly caused by claw lesions (Mülling and Lischer, 2002) especially in the hind limbs (Knott et al., 2007). These claw lesions do not only cause considerable animal welfare problems but also generate economic losses due to decline of milk yield and fertility (Bicalho et al., 2008; Cha et al., 2010; Liang et al., 2017). The bovine claw is the interface between the dairy cow and the environment. Anatomically, the claw is designed for stance and locomotion on pasture type ground and requires limited periods of standing. Standing and walking on hard floors and extended periods of standing inevitably lead to damage of the interior structures of the claw. We have gained considerable insight in the impact of the cow’s environment on claw structure and function. The impact of the environment is either directly mechanical, chemical or biological or indirectly by altering the cow’s behavior and secondary causing damage to the claw tissues. Environmental factors, cow comfort and cow behavior are understood as key factors in the multifactorial etiology of claw diseases and in lameness prevention (Barker et al. 2009; Cook and Nordlund, 2009; Cook et al., 2004). Claw lesions are inevitably associated with indoor housing systems. It is nowadays well established that non-infectious claw lesions, which develop subsequent to initial tissue alterations associated with claw horn disruption (CHD), have a multifactorial etiology. And they have a strong biomechanical component in their etiopathogenesis. It has been suggested more recently that mechanical influences and mechanically caused or initiated tissue alterations in the claw maybe the predominant or even exclusive cause for CHD lesions. The idea of a predominantly mechanical etiology is not new. In 1920 Anton Rusterholz published two articles on “the specific-traumatic sole ulcer in cattle” in the Swiss Archives for Veterinary Medicine (Schweizer Archiv für Tierheilkunde – SAT) (Rusterholz, 1920). He provided a detailed anatomical description of the ulcer, which was later on named after him. He also described the etiology and pathogenesis in depth and established a direct causal link between housing, namely hard floor, and the development of bone exostoses on the distal phalanx and subsequently ulcers (see figure 1). Rusterholz also postulated a genetic component in the etiopathogenesis. Genetics nowadays receive rapidly growing attention in more recent research and genetics provide powerful opportunities to enhance claw health by genetic section (Heringstad et al., 2017). […]