Wednesday, 14 November 2012

Foal feet and hoof development

A few people have been asking about Bryher's feet - so here they are...

Its tricky getting good photos because, of course, he is only 4 months old and though he is obliging about picking his feet up, he doesn't keep still for long. Shots from this angle are easier and you can already see some very distinct bands of growth.

My best guess is that the lower ring is from when he first started to stomp about on his feet (at the beginning of July) and the band just over halfway down is when he came to Rockley, about 2 months ago. 
One of the most interesting things about foals is the shape of the foot - a completely different profile to an adult foot (in other words, wider at the top, narrower at the bottom rather than the opposite way). 

Over the first few months and years of a foal's life the foot changes and grows and I would expect comparative photos of Bryher this time next year to show a foot which is closer to an adult shape. But how does this happen?

Prof Bob Bowker theorises that hooves don't simply grow down from the coronet but actually develop in response to movement and stimulus from the ground. This fits with the fact that - in humans - reproduction of cells in the epidermal layer of skin (in your fingertips and feet) can be triggered by friction and stimulus, resulting in thicker skin in these areas as a response. 

This is a unique response but if we realise that the horse's hoof is - anatomically - a digit then it makes sense that stimulus to the hoof will cause it to become more robust. 

If a hoof only grew from the coronet horses would retain the foal hoof shape throughout their lives. However if the cells of the hoof grow in response to ground stimulus too, it would make perfect sense that the shape of the hoof would change as the foal started to walk and run on the ground and the inverted cone would become broader at the base. 

Just imagine what happens when you reduce or cut off that stimulus!

Its going to be fascinating to chart Bryher's hooves over the next few months and years!


dea i Campina said...

I don't agree that "This is a unique response not found in other cells"! What about bone tissue response to stimulus? Bones getting weaker are a big problem for astronauts. What about muscle tissue response to training? Tendon tissue strengthening? Brain making connections and developing when learning? Blood vessels getting bigger when there is a greater need for oxygen/food (I've got some Popeye-like veins in my right arm because of the trimming I do ;)), etc etc...

Bottomline: EVERYTHING in a living organism responds to the stimulus that it gets! An organ not used disappears - it's a known truth :)

Best regards from Poland! the land of "contracted tendons"...

Nic Barker said...

Hi Kasia,

You are right, of course, that bone and soft tissue changes in response to (and depends on!) stimulus. That's one of the factors I see in hooves here every day.

What I meant in the blog (and I will clarify it - apologies!) is that there is a layer of epidermal cells in the feet which are uniquely capable of cell reproduction in response to stimulus. In other words in humans the skin on feet and hands becomes thicker in response to friction.

The same must be true of the epidermal cells in the hoof, surely?

Jane said...

Remus is now 18 months old and he already has the beginnings of adult feet.... They have looked for a little while a bit contracted... As I guess they will when they go from foalie to teenage feet. He also grew a much longer hoof wall, especially at his toe. At one point I ALMOST thought about getting a rasp out, lol.

A month later and his heels have spread more and his toes are back to the right length. And they now look like mini horse feet. It's fascinating!

Glad you are doing the photo thing as I've never been bothered!

dea i Campina said...

Thanks for the clarification, Nic :)

Andrea said...

Holy MOLEY those foal feet are LONG! I am so used to our nice dry climate foal feet - the babies turned out here develop these low strong heels and short walls almost immediately, they look like tiny little wild mustang feet so long as they stay out all the time and run around.

Nic Barker said...

LOL! Don't worry Andrea - he does stay out and run around - on all terrain - and his hooves are actually short when you look at the sole - no long hoof wall here, I promise you :-) I suspect what makes his hooves look different is that the photos are taken at ground level and hooves look a lot different from this angle than when you are standing looking down on them.

Andrea said...

Might be the angle! All our little foalie feet look like the ones pictures here: Low to the ground and perfect and CUTE!