The role that concrete plays in dairy cow lameness cannot be overemphasised. This is something that was explained in Part 2 of this series. To understand why dairy cows so often become lame in the hind feet, we need to study this aspect.
Contrary to popular belief, cows are not heavier at the back than in front. Cows carry 60% of their body weight on their front feet and 40% on their hind feet. If they do not carry more body weight at the back, why do they experience up to 95% of all mechanical lameness in the hind feet?
Again, it has to do with shock absorption on non-yielding surfaces, but we need to bear the conformation of the cow in mind. The front legs are connected to the skeleton by means of muscles and ligaments and, therefore, allow more movement and suspension. The front leg can easily be amputated with a knife if you cut it high enough up in the shoulder. The hind legs are part of the skeleton, and all the bones are connected by means of joints so they cannot easily be removed with a knife.
The P3 bone in the foot creates more haemorrhage on the corium because there is more concussion on the concrete. The corium is responsible for horn production. A healthy corium produces a healthy hoof capsule for protection. However, in the case of an unhealthy corium, the haemorrhage on the corium creates a horn with pores filled with old blood, which is the ideal habitat for anaerobic bacteria to grow and form a sole ulcer or white line lesion.
I encourage you to take a close look at the pictures provided in order to understand the above explanation.
Image source: vladimirclar
Guest Writer & Consultant to DairySmid: Jaco de Bruin