PERFORMANCE AND BEHAVIOR OF EARLY–WEANED PIGS IN HOOP STRUCTURES

Abstract

A series of six trials involving a total of 1,440 crossbred nursery pigs (6.7kg initial wt) was conducted at two IowaState University research farms from December 1999 to August 2000. Three smallscale hoop structures (6.0 . 10.8 m) weredivided 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 mechanicallyventilated confinement nursery with slatted floors were used for comparison with the hoop structure pens for each 5weektrial. The hoop pens were equipped with hovers and heat lamps for the winter and spring trials. In each trial, 240 crossbrednursery 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 theduration of each trial. During the first 2week postweaning, the pigs in hoop structures grew 23% slower (P < 0.001) andconsumed 23% less feed (P < 0.001) than the pigs in confinement. Both housing systems had similar Average Daily Gain(ADG), Average Daily Feed Intake (ADFI), and Gain:Feed (G:F) for the last 2 weeks of the trial (p > 0.10). As expected,the performance parameters (ADG, ADFI, G:F) were affected by the building and season interaction during each 35daytrial. In all seasons, the hoop pigs ADG and ADFI were less than the confinement pigs for the first 2week postweaning (P< 0.05). During the winter, overall (5 weeks), the pigs in hoop structures grew 5% slower and consumed 9% less feed, butwere 5% more efficient converting feed to live weight gain than the pigs in confinement (P < 0.05). In the spring, the pigsin hoop structures grew 7% slower (P < 0.05), consumed 6% less feed (P < 0.05), and had similar feed efficiencies (P > 0.05)as the pigs in confinement during the 5week 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 5week trial.Bedded hoop structures have not been widely studied as a cold nursery facility during the colder months. The results suggestthat older, heavier pigs may perform better when placed directly into a cold facility such as a hoop structure. Further trialswith adjustments made to the bedding, heat source, hovers, feeders, and management may improve the growth performance.