Performance and Leg Conditions of Caged and Floor Reared Broilers Fed Diets Deficient in Selected Vitamins and Minerals

Abstract

A study was initiated in which the performance and leg condition of male broiler chickens fed corn-soybean diets, deficient in certain vitamins and minerals known to influence leg abnormalities, was observed. Birds were reared in either floor pens or wire or plasticcages. Birds consuming diets deficient in biotin, choline, folacin, or niacin gained significantly (P<.01) less weight and ate less feed than did control birds, but birds on a manganese deficient diet grew as well as the controls. With vitamin deficient diets, caged reared birds were significantly (P<.01) heavier than were floor reared birds. No classical deficiency symptoms were observed for any of the treatments. Birds offered vitamin deficient diets exhibited a significantly (P<.01) greater incidence of leg disorders. They were generally reluctant to move and both “knock-kneed” and “bow-legged” conditions were observed, although it was not possible to differentiate treatment differences in locomotion by visual observation of from studying a film made of their activity. It is suggelted that inferior performance of floor reared vs. caged birds fed vitamin deficient diets is related to their reluctance to move due to leg disorders. Cage birds were generally within 30 cm of their feed source, while in floor pens birds had to move anywhere up to 2 m to reach the feeder.