The age of cattle is determined chiefly by examination of the teeth, and less perfectly by the horn rings or the length of the tail brush; due to bang-tailing, which is the act of cutting the long hairs at the tip of the tail short to identify the animal after management practices, the last method is the least reliable. Teeth method Cattle are placed in a cattle crush in order to restrain them prior inspecting the mouth and amount of teeth that each animal has. The temporary teeth are in part erupted at birth, and all the incisors are erupted in twenty days; the first, second and third pairs of temporary molars are erupted in thirty days; the teeth have grown large enough to touch each other by the sixth month. Temporary incisors or "milk" teeth are smaller than the permanent incisors. Cattle have thirty-two teeth, including six incisors or biting teeth and two canines in the front on the bottom jaw. The canine teeth are not pointed but look like incisors. The incisor teeth meet with the thick hard dental pad of the upper jaw. Cattle have six premolars and six molars on both top and bottom jaws for a total of twenty-four molars. The teeth of cattle are suited primarily for grinding, and they use their rough tongues to grasp grass and then nip it off between their incisors and the dental pad. There is controversy on the reliability of attempting to tell the age of cattle by their teeth, as rate of wear can be affected by the forage that is grazed. Drought or grazing on sandy country will also affect rate of wear. The following is a guide: 12 months – All the calf teeth are in place. 15 months – Centre permanent incisors appear. 18 months – Centre permanent incisors showing some wear. 24 months – First intermediates up. 30 months – Six broad incisors up. 36 months – Six broad incisors showing wear. 39 months – Corner teeth up 42 months – Eight broad incisors showing wear. The development is quite complete at from five to six years. At that time the border of the incisors has been worn away a little below the level of the grinders. At six years, the first grinders are beginning to wear, and are on a level with the incisors. At eight years, the wear of the first