THE INCIDENCE AND DISTRIBUTION OF OCHRATOXIN-A IN WESTERN CANADIAN SWINE

A survey of swine destined for slaughter in Manitoba was conducted to examine the incidence of ochratoxin A (OA) in swine herds from differe nt regions of Manitoba throughout the year 1989-90. Thirty-six percent of the serum samples which were collected from 1600 pigs contained de tectable levels of OA. The identity of this toxin was confirmed using liquid chromatography-mass spectrometry and enzymatic hydrolysis. Ther e was a significant effect of the region from which the herds originat ed, as well as the season in which the samples were collected on both the incidence (p < 0.001) and concentration of OA (p < 0.001). In July , 65% of the samples contained detectable levels of OA, compared with 38, 21 and 17%, in April, October and January respectively. Furthermor e, 24% of the samples collected in July contained greater than 15 ng/m l of OA, while only 2, 9, and 1% of the samples collected in April, Oc tober and January respectively, contained greater than 15 ng/ml of OA. Based on the six samples collected from each herd, it appears that th e presence and concentration of OA within a herd may be estimated from a limited number of animals per herd.