EFFECT OF HOUSING SYSTEM ON THE RECOVERY OF BOARS FROM LEG WEAKNESS

Abstract

A total of 30 market weight boars, including 25 lame animals and 5 normal animals, were obtained from a swine performance testing station to study the effect of housing system on the recovery from lameness. Boars were housed in 1.7 × 2.0-m concrete floor pens with straw as bedding and allowed access to a 4 × 23-m indoor concrete area for 2 h per day (group I) or in outdoor sheds which opened onto 10 × 15-m dirt lots (group II). During the 7-wk experimental period, there was no appreciable improvement in locomotory ability in any of the animals studied. Though gait was slightly improved in one of the boars from each group, postmortem examination of joints revealed considerable degeneration of the articular cartilage surfaces. The incidence and severity of joint lesions in the 18 lame pigs were greatest (P < 0.05) in the proximal articular surface of the ulna, the distal articular surface of the humerus and the distal articular surface of the femur. Lesion occurrence and severity were similar between boars from groups I and II. No differences (P > 0.05) were observed in any of the performance characteristics among normal and lame boars that completed the experiment.