Risk factors for infertility in nursing cows linked to calving.

An ecopathological survey was conducted between 1987 and 1989 in 116 French herds with 3,590 cows in order to study the risk factors for infertility linked to calving. Based upon an analysis model of etiological interactions, the complementary use of a logistic model and factorial analysis followed by classification allowed demonstration of the direct and indirect, effects upon infertility, breed factors, parity, fattening, comfort, calf characteristics (number, sex, weight, presentation), as well as the difficulty and complications which may have been associated with calving. By association, these factors determine the profile of the cows at risk.