[Continuing eco-pathological survey: 4. Demonstration of pathologic associations in dairy cow stock: herd data]

Data concerning frequencies of 17 main diseases in 59 dairy farms from continual eco-pathological survey, are analyzed by classical regression test, principal components analysis and analysis of variance. Thirty-three statistical relations (positive simple correlations) are shown. Clinical mastitis and retained placenta are associated to nine diseases each, metritis, stillbirth and non-infectious foot disorders to six, dystocia and infectious foot disorders to four, pathology of calf and abortion to three, mammary edema and appetite disorders to two. Ovarian pathology, digestive disorders and teat lesions are "isolated", being associated to only one other disease. The pathological frequencies in dairy farms seem to change in the same way, indicating the existence of common risk factors, and leading to propose a global hygienic prevention. The pathological associations allow to definite some groups of dairy farms showing one or other dominant pathological complex. In the frame of our sample of dairy farms, two groups seem to be determined: one with calving disorders and calf pathology centred on retained placenta, the other with foot disorders, infectious and metabolic troubles, centred on mastitis, as dominant diseases.