THE GROWTH OF THE HOOF.

Otago Witness, Volume 14, Issue 2648, 14 December 1904, Page 6

THE GROWTH OF THE HOOF.

Horse breeders in general will be interested in knowing .just how the growth of the hoof of a horse takes place. In '•Farmers' Bulletin,"' No. 179, of the United! States Department of Agricultuie, Dr I. W. Adams, in a treatise on '•Horse-shoe-ing," submits an interesting discussion of the question. He says : "All parts of the hoof grow downward and forward with equal rapidity, the rate of growth bslng largely dependent upon the amount ol blood supplied to the pododerm. or quick. Abundant and regular exercise, good) grooming, moistness, and suppleness oi the hoof, going barefoot, plenty of good food, and -it proper intervals removing the overgrowth of hoof and regulating the bearing surface, by increasing the volume and improving the quality of the blood flowing into the pododerm, favour the rapid growth of horn of good - quality ; while lack of exercise, -dryness of the horn, and excessive length of the hoof hinder growth.'" It is stated that the average rate of growth is about one-third of an inch a month. Hind hoofs grow faster than fore hoofs, and> unshod hoofs faster than shod ones. The time required fur the horn to grow from the coronet to the ground, though influenced to a slight degree by the precited conditions, varies in proportion to the distance of the coronet from the ground. "At the toe, depending on its height, ths ixorn grows down in 11 to 15 months, at the side wall in six to eight months, and at the heels in three to five months. We can thus estimate with tolerable accuracy tbe time required for the disappearance of such defects in the hoof as cracks, clefts, etc." It is pointed out that breeders of hor&es will therefore undeistand why irregular growth is not infrequent. The almost invariable cause of this is an improper distribution of body weight over the hoof — that is, an unbalanced hoof. Colts running in soft pasture or confined too long in the stable are frequently allowed to grow hoofs of excessive length. Ths long toe becomes "dished" — that is, concave from the :oronet, the long quaiters curl forward and inward, and often completely cover the frog, and lead to contraction of the heels, or the whole hoof bends outwards, and a crooked) foot, or ■even worse, a crooked 1 leg, is the result, "if the long hoof be allowed" to -exert its powerful and abnormally directed leverage for but a few months upon young, plastic bones and tender and lax articular ligaments/ All colts are not foaled with straight legs, but failure to regulate the bearing on the hoof may make a straight leg crooked, and a crooked leg worse, just as intelligent care during the growing period can greatly improve a congenitally crooked limb. If bleeders were more generally cognisant of the power of overgrown and' unbalanced hoofs to divert the lower bones of young legs from their proper direction, and therefore to cause them to be moved improperly, and with loss of action and speed, and often with injury to the lainbt., "we might hope for fewer knock-kneed, bow-legged, splay-footed, pigeon-teed, cow-hpeked, interfering and paddling horses."

If, in shortening the hoof, one' side wall 'is. from ignorance, left too long, or cut too low, with relation to the other, the foot will be unbalanced, and in travelling the long section will touch the ground first, and) will continue to do so until it has been reduced to its proper level (length) by the increased wear which will take place at this point. While this occurs rapidly in unshod hoofs, the shoe prevents the wear of the hoof, though it is itself more rapidly worn away beneath the high (long) sides than elsewhere, so that by the time the shoe is worn out, the tread of the shoe may be flat. If this mistake bs- repeated from month to month, the part of the wall left too high will grow more rapidly than the low side, whose podbSarm (quick) is relatively anemic as a result of the greater weight falling ".on to this half, and the ultimate result will b& a "wry" or crooked hoof.

In the care of unshod hoofs, the colt should have abundant exercise on dry ground. The hoofs will then wear gradually, and it will only be necessary from time to time to regulate any uneven wear with the rasp, and to round off the sharp edge about the toe in order to prevent breaking away of the wall.

Colts in the stall cannot wear down their hoofs, so that every four to six weeks they should be rasped down, and the lower edye well rounded to prevent chipping The soles and clefts of the frogs &hou?d be picked out every few days, and the entire hoof washed clean. Hoofs that are becoming "awry" • should have the wall shortened in such a manner as to strengthen the foot axis. This will ultimately produce a good hoof, and will improve the position of the limb.