Influence of farm, feed-producer and season on incidence of gastrointestinal disorders in Danish farm mink

The distribution of gastrointestinal disorders in mink in Danish farms is p resented based on data collected in a longitudinal design. The time at risk was from weaning in June until pelting in November. The occurrence of gast rointestinal disorders after weaning of the mink kits together with the dis tribution within farms was studied. The period of highest risk was in the m onths immediately after weaning (July and August). More than 17% of the far ms recorded GI disorders among greater than or equal to 10% of pairs of ani mals. A multilevel statistical analysis showed that besides the effect of t ime after weaning, a significant part of the variation in the incidence cou ld be attributed to the farm and feed-producer. The potential for bias is d iscussed. (C) 1999 Elsevier Science B.V. All rights reserved.