TELLING A SHEEP'S AGE.

Otago Witness, Issue 3292, 18 April 1917, Page 8

TELLING A SHEEP'S AGE.

Some short time ago the question cropped up as to what constituted a "failing" or "broken" mouth sheep, and, in consideration of the fact that many more or less inexperienced men are taking up grazing lands, it may prove of interest to pursue the subject further. Without being dogmatic, it may be stated that a sheep's age may be fairly well arrived at for general purposes by an examination of the teeth, although probably it would puzzle a "professor" to decide the exact age of some of the "jumbucks" off the hills. The alteration which takes place in a sheep's mouth during the process of dentition is admittedly variable, depending a good deal upon the conditions under which the sheep are grazed. In the Homeland it is not the custom to sell sheep by the teeth —it may be because they get more artificialjffeed, and have a shorter life than in the colonies. However, be that as it may, sheep certainly are sold there as lambs, tegs or hoggets, shearlings, twoshear sheep, three-shear sheep, and aged (foxn years and upwards); but with us it is not infrequent to find sheep going str:.ig at eight, 10, or more years old. After a ;eheep is full-mouthed it is not an easy matter to tell its age away from its own country, unless one is made aware of the attending circumstances, as the wear of the teeth depends largely on the class of country and the early or late maturity of the breed. With a good general know ledge, however, it is possible to get along without making any very great blunders. When full mouthed a sheep has 32 teeth—viz., eight inckors or cutting teeth, and 24 molars or grinders. They come in the -following order, and although few sheepmen take much note of the molars or grinders when assessing the age, yet, as they are all in place and complete before the incisors, we will mention them first. At a month old the lamb has three molars in each of its supper and lower jaws, and at three months old the 4 ' fourth molar is cut, and is a permanent tooth. At nine months another molar—the fifth—is to be seen. At 18 months the sixth molar is cut. The third temporary molar, like a shell, covers the top of the permanent tooth, and the first and second permanent molars have pushed, out the temporary ones. Thus a sheep has all its permanent molars at 18 months to two years old. The cutting teeth are, however, of more immediate concern as a practical guide to the age of the sheep, and they come somewhat as follows: —At birth a lamb possesses two central temporary incisors, and at four weeks old all the temporary incisors (eight) are up.- These temporary incisors will usually remain from 10 to 15 months (depends upon the feed), when the first two central permanent incisors make their appearance. At 18 to 24 months the second pair of perma-. nent incisors are up, at from 27 to 33 months the third pair are in use, and from 35 to 42 months the fourth and corner pair of permanent incisors are showing, and the sheep is " full mouthed" at approaching four years of age. Up to this stage there is not usually very much trouble, but we come then to '/good," "fair," and "failing" mouths; "broken." "ground," and "hooked" teeth, "gummies," etc., all of which may fairly come under the designation "culls" The terms "good," "fair," and "failing " obviously indicate that the sheep is part full-mouth. "Broken" may well serve to embrace all sheep not having their full complement of incisors and those with chipped teeth; "ground," those with worn teeth, but not necessarily indicativs of aged or done sheep, but sheep that have probably been grazed on short, salty herbage in a gritty or sandy area, and the teeth have been ground down; in fact it is not an uncommon thing to find young six-tooth ewes with their teeth ground down as fine as the end of a wax vesta match. These sheep when removed to different pasture will grow their corner teeth full size, with a consequent result of a malformed mouth, and the result of again turning them back on to short herbage can be best Imagined. " Hooked " teeth may include any aged sheep which, gifted with an excellent constitution, hold to their teeth, which grow freely and fantastically as the result of feeding for a long time in succulent feed ; " gummies," not necessarily very old sheep, but which either from climatic, constitutional, or local conditions have cast their front teeth comparatively early. It is not improve the mouths of sheep having, "say, a few odd, loose, wobbly incisor teeth by removing these, and thus enable the animals to " do " better with some comfort to themselves and more profit to their owner.