Previous studies have demonstrated that as weaning age in piglets decreases, the frequency of belly-nosing and bellysucking increases. The objectives of this study were to determine whether Duroc and Yorkshire genotypes differed in the percent of time spent belly-nosing, bellysucking, and other nosing and sucking. In addition, the effects of number of days (7 vs. 14) spent on a liquid diet, gender, and pen enrichment (nippled troughs, innertubes, and control) were investigated to determine whether specific management practices affected the incidence of these behaviours. By studying how breed differences (Duroc versus Yorkshire) affect the amount of time spent nosing and sucking, it may be possible to select genotypes better suited to the S.E.W. environment. Although Segregated Early Weaning (S.E.W.) was initially employed as a means of eradicating disease in swine operations, little is known about how management factors affect the incidence of belly nosing and belly sucking in early weaned pigs. A study was designed to investigate the effects of genotype, diet form and pen enrichment on the incidence of these behaviours in piglets weaned at 7 days of age. In the Control (barren environment) treatment, Yorkshires engaged in more belly sucking, total sucking, and belly directed behaviour than did Duroc piglets (see figures 1 and 2). The Nipple, and to a lesser degree the Tube, treatment reduced the incidence of belly sucking and total sucking within the Yorkshire piglets, but had little effect on the Durocs, which were already at low levels. Thus, there was a significant genotype/environmental enrichment interaction. For the genotype with high levels of belly directed and sucking behaviours, environmental enrichment was effective in lowering the incidence of these behaviours to that of the low incident genotype.