My farrier told me that they aren't, not to worry. He also told the barn manager that he isn't a very good farrier. I'm just wondering what other people think of corks. Dear Jaimie, Corks,inserts, or now more commonly called jar calks are used on the front feet of thoroughbreds for racing in muddy, sloppy, race tracks. They are put on under these conditions only and usually removed after racing or as soon as possible thereafter.
Many trainers are convinced that jar calks are necessary to maintain a horses stability in mud.
Most race tracks will not allow them to be used on the grass or on a fast track. We manufacture them as does our competitors. If it rains hard and heavy for one, two or three days straight, there will be more of a demand from our distributors for jar calks. It is always the trainer's decision to use them. In my opinion, if it were my horse, I would not use the Jar Calks and try to wait for better track conditions.