This paper presents a first approach of the health over the whole life
-cycle of dairy cows, a scale which is intended to define a trajectory
. Trajectories are defined as the chain of health profiles on the lact
ation scale, which are characterized by major disorders: foul of the f
oot; lameness; arthritis; calving disorders; mastitis; digestive and m
etabolic disorders; and no disorders. A few examples of trajectories a
re discussed for life-cycles lasting 4 lactations.