Catwalks should run alongside the fences, not overhead. Enough meat to feed a large city is thrown into the rendering tank as a result of bruised livestock carcasses. Bruised meat cannot be used for human food. Ranchers and other producers who market young stock should also be interested in reducing bruising, because bruises and injuries lower animal performance. Two-thirds of all loin bruises occur during loading and unloading from trucks.
Thin cows bruise more easily than choice steers.
Cattle which go through stockyards haw more bruises than cattle sold directly to the plant. In one survey, cattle sold on a live weight basis had twice as many bruises, compared with cattle sold on the rail. Producers who sell on the rail have the bruises discounted from their payment, since the bruises are trimmed away before the carcass is weighed. Ten percent of all fed lambs have carcass damage. The most common cause of bruising is grabbing sheep by the wool or by the hind leg.