Tuesday, 10 December 2019
The first step of the Five Step Method is to measure the dorsal wall length of the medial claw of a hind foot to a suggested length of 75mm. It may surprise you to find that there is actually very little evidence base for this measurement.
In fact, if you go back to the original Toussaint-Raven description it doesn’t even state where you should measure from and to, leaving much ambiguity.
The experienced trimmer will naturally judge the appropriate toe length for the individual cow. However, this isn’t much use when trying to train a novice to trim – how do you ‘teach’ experience? As part of my AHDB PhD studies with University of Nottingham I conducted a cadaver study to determine whether we can standardise toe length and which external measurement is the best predictor of sole depth at the tip of the pedal bone.
After cutting up nearly 400 claws and taking over 11,500 measurements, a preliminary analysis suggests that measuring from where the horn is palpably hard is the most consistent to be predictive of sole depth (see Figure 1). Then, a toe length of 85mm may be more appropriate than 75mm for most cows. However, this measurement is not very repeatable between individual trimmers, and so further consideration of predictiveness and repeatability is needed before determining recommended guidelines. I will keep you posted on that as the study develops.
Anyone who trims dairy cows’ feet is invited to enter a survey which will gather information on the current approaches to foot trimming. The results of the survey will help shape future studies with the aim of providing better information at farm level as to the most effective trimming protocols required to prevent lameness.
By completing the questionnaire, you have the opportunity to enter a prize draw to win a signed copy of Roger Blowey’s ‘A Veterinary Book for Dairy Farmers’.