EFFECTS OF TYPE OF CONFINEMENT ON PERFORMANCE AND ON THE OCCURRENCE OF LOCOMOTORY DISTURBANCES IN MARKET PIGS

Abstract

Twenty-four crossbred pigs were divided into three groups of eight to study the effects of confinement on performance and the occurrence of crippling in market pigs. The three groups were confined as follows: individually in concrete-floored pens 0.6 × 1.2 m, with or without an expanded metal platform, or in groups of four in concrete-floored pens 1.4 × 2.5 m. Confinement of pigs in pens 0.6 × 1.2 m with a half-slotted concrete floor, with or without an expanded metal platform, resulted in a significantly (P < 0.05) lower rate of gain, an increased feed conversion ratio (feed per unit gain), a significantly (P < 0.01) reduced cross-sectional area of cortical bone (midshaft, left femur), and a significantly (P < 0.01) decreased breaking strength (right femur) of bone in comparison with pigs confined in groups of four in pens 1.4 × 2.55 m. No significant differences in feed intake or percent bone ash were noted. Gross postmortem findings and histologic changes observed in articular cartilage are described.