Space requirements of barrows and gilts penned together from 54 to 113 kilograms

Two experiments, involving six experiment stations in the North Central Region of the United States, were conducted to examine the space requirements of mixed-sex pigs (barrows and gilts) from 54 to 113 kg live weight. In both experiments, corn- or milo-soybean meal-based diets were formulated within stations to contain.6% lysine and no growth-promoting feed additive. In Exp. 1, entire pens of pigs given.56,.74, or.93 m2/pig remained on test until the week that the individual pen of pigs weighed greater than or equal to 113.6 kg. In Exp. 2, treatments were.56,.74,.93, and 1.11 m2/pig and individual pigs were removed during the week that they weighed greater than or equal to 113.6 kg. There was a linear (P .005) improvement in ADG in Exp. 1 for the.56,.74, and.93 m2/pig treatments (.64,.69, and.72 kg/d). This response was accompanied by a linear (P .05) improvement in gain:feed (.247,.258, and.261, respectively). In Exp. 2, the linear (P .0005) response of ADG to increasing space allocation (.71,.76,.80, and.81 kg/d for the respective treatments) and the linear (P .005) improvement in gain:feed (.265,.268,.274, and.281, respectively) suggested that pig performance reached a plateau. These results suggest that performance of pens of mixed-sex pigs grown to 113 kg live weight was maximized at the.93 m2/pig space allocation