Assessment of risk factors for culling dairy cows using logistic regression. Definition of outcome and explanatory variables.
The culling of dairy cows can occur either early or late during lactation. Furthermore, the farmers decision-making process is probably not identical for cows culled early in lactation and for cows culled later. Most of the studies investigating associations between diseases and culling were performed without considering the time of culling during lactation. The present study defines d 45 post partum as a threshold between early and late cullings, and proposes 2 lists of possible risk factors, whether cows were culled early or late during lactation.
Beaudeau
F
F
INRA, Ecole Nationale Vétérinaire, Laboratoire de Gestion de la Santé Animale, Nantes, France.
Fourichon
C
C
Billon
D
D
Seegers
H
H
D000822:Animal Husbandry / Q000706:statistics & numerical data*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000191:economics / Q000453:epidemiology*; D005260:Female; D007775:Lactation Disorders / Q000191:economics / Q000453:epidemiology / Q000662:veterinary*; D016015:Logistic Models; D008137:Longitudinal Studies; D011446:Prospective Studies; D011996:Records / Q000662:veterinary; D012307:Risk Factors; D013997:Time Factors