EN
In an orchard farm with stud horses the number of sick horses increased. In adult horses an increased percentage of obstipation, transient lameness, sterility of mares and asymptomatic abortions at the 3rd month of gestation was observed. In colts at the age of 6 months 1.5 years tendon contractions, edema of carpal and tarsal joints, stiffness, loss of appetite and deformation of attitude often were noted. Fracture of femural bones, ribs and cervical part of vertebral column were associated with most of the breakdowns. Hematological and biochemical parameters of blood were normal. An analysis of fodder revealed deficiency of Ca, Zn and Cu. A supplementation of fodder with these minerals did not improved the state of the horses health which suggested a blockade of absorption of these elements from the alimentary tract. It appeared that oat used as fodder was harvested from interlines in an orchard in which herbicides had been intensively applied for 15 years. After 3 months since the removal of this oat from fodder a remarkable improvement in the state of horses health was noted.