Performance and Behavior of Early-Weaned Pigs in Hoop Structures

A series of six trials involving a total of 1,440 crossbred nursery pigs (6.7-kg initial wt) was conducted at two Iowa State University research farms from December 1999 to August 2000. Three small-scale hoop structures (6.0 × 10.8 m) were divided lengthwise to form two pens (3.0 × 4.5 m) per building for a total of six pens. Six pens (1.7 × 4.0 m) in a mechanically ventilated confinement nursery with slatted floors were used for comparison with the hoop structure pens for each 5-week trial The hoop pens were equipped with hovers and heat lamps for the winter and spring trials. In each trial, 240 crossbred nursery pigs were weaned at 18 to 22 days old and allotted by weight and litter to one of the six pens found in either the hoop (n = 120) or confinement (n = 120) nursery facility. Four commercial diets were fed in both housing systems in phase for the duration of each trial During the first 2-week postweaning, the pigs in hoop structures grew 23% slower (P 0.10). As expected, the performance parameters (ADG, ADFI, G:F) were affected by the building and season interaction during each 35-day trial In all seasons, the hoop pigs' ADG and ADFI were less than the confinement pigs for the first 2-week postweaning (P 0.05) as the pigs in confinement during the 5-week trial. During the summer, the pigs in hoop structures grew similarly (P > 0.05), consumed 6% less feed (P < 0.05), and were 8% more efficient (P < 0.05) than the pigs in confinement for the 5-week trial Bedded hoop structures have not been widely studied as a cold nursery facility during the colder months. The results suggest that older, heavier pigs may perform better when placed directly into a cold facility such as a hoop structure. Further trials with adjustments made to the bedding, heat source, hovers, feeders, and management may improve the growth performance.