Quantitative evaluation of the relationship between dorsal wall length, sole thickness, and rotation of the distal phalanx in the bovine claw using computed tomography

Abstract

Computed tomography (CT) was performed on 800 untrimmed claws (400 inner claws and 400 outer claws) of 200 pairs of bovine hindlimbs to investigate the relationships between dorsal wall length and sole thickness, and between dorsal wall length and the relative rotation angle of distal phalanx-to-sole surface (S-D angle). Sole thickness was 3.8 and 4.0 mm at the apex of the inner claws and outer claws, respectively, with dorsal wall lengths <70 mm. These sole thickness values were less than the critical limit of 5 mm, which is associated with a softer surface following thinning of the soles. A sole thickness of 5 mm at the apex was estimated to correlate with dorsal wall lengths of 72.1 and 72.7 mm for the inner and outer claws, respectively. Sole thickness was 6.1 and 6.4 mm at the apex of the inner and outer claws, respectively, with dorsal wall lengths of 75 mm. These sole thickness values were less than the recommended sole thickness of 7 mm based on the protective function of the soles. A sole thickness >7 mm at the apex was estimated to correlate with a dorsal wall length of 79.8 and 78.4mm for the inner and outer claws, respectively. The S-D angles were recorded as anteversions of 2.9° and 4.7° for the inner and outer claws, respectively, with a dorsal wall length of 75 mm. These values indicate that the distal phalanx is likely to have rotated naturally forward toward the sole surface. The distal phalanx rotated backward to the sole surface at 3.2° and 7.6° for inner claws with dorsal wall lengths of 90-99 and ≥100 mm, respectively; and at 3.5° for outer claws with a dorsal wall length ≥100 mm. Dorsal wall lengths of 85.7 and 97.2 mm were estimated to correlate with a parallel positional relationship of the distal phalanx to the sole surface in the inner and outer claws, respectively.

Claw length recommendations for dairy cow foot trimming

“…In agreement with increasing recommended claw length, Tsuka and others (2014) suggested 79 mm was more appropriate than 75 mm, and Nuss and Paulus (2006) reported a cut length of 80 mm left 29 per cent of claws with inadequate sole depth. The current study reports longer lengths may be required, but the authors assumed that the toe would be trimmed to a point.…”

“…Eleven sources related to claw dimensions; of which, two were peer reviewed ( Manske and others 2002 , Tsuka and others 2014 ), and the most commonly recommended dorsal wall length was 75–80 mm (eg, Blowey 2004 ), with a range of 60 ( Greenough 2007 ) to 85 mm ( Blowey 2008 ). Landmarks for the proximal dorsal wall limit were either not defined (eg, Toussaint-Raven 1985 ) or defined inconsistently; examples included the ‘proximal end of claw capsule’ ( Manske and others 2002 ), the ‘distal edge of the periople’ ( Tsuka and others 2014 ) or imprecise terms such as coronary band or coronet (eg, Nuss and Paulus 2006 , Blowey 2008 ). Recommended shape of the toe differed between sources, and different trimming techniques would require adaptation of dorsal wall length to achieve adequate sole thickness.…”

Reliability of ultrasonographic measurements of bovine sole structures in relation to sole horn thickness, measured by computed tomography, and sole horn hardness

“…Thicker sole horn is commonly associated with claw overgrowth, which occurs primarily at the apical region of the claw when foot trimming is not done regularly (Shearer and van Amstel, 2001). Overgrown claw horn may lead to unsteady gait and excessive weight-bearing on the flexor tuberosity, resulting in injury to the corium within the horn capsule and sole ulceration (Tsuka et al, 2014). Thin sole is an abnormal condition associated with an SHT of <5 mm, which may lead to bruising of the corium (Kofler et al, 1999;van Amstel et al, 2003van Amstel et al, , 2004Laven et al, 2012).…”

“…Computed tomography (CT) has been used for quantitative evaluation of bovine claw structures (Kofler et al, 1999;Tsuka et al, 2014), and provides basic axial 2-dimensional (2-D) images. Reconstruction of 2-D images to the level of the mid-sagittal region is the most useful method for measurement of SHT (Kofler et al, 1999;Tsuka et al, 2014). A strong correlation (r = 0.97-0.98) was observed between macroscopic and CT measurement of SHT (Tsuka et al, 2014).…”

Effects of mechanical loads on the deformation and health status of claws in dairy cows

“…Excessive thinning of soles at trimming is regarded as a risk factor for claw disorders (Nuss and Paulus, 2006). Dairy cows currently are much bigger than those present when the trimming method was developed (more than 30 years ago), and this may not always be taken into account correctly (Tsuka et al, 2014;Archer et al, 2015). Therefore, on concrete floors the standard method is probably to be preferred.…”