Enlargement of farms in association with the decrease in the family workforce are inducing the development of permanent wage earners. In dairy farms, permanent wage earners have been recruited to carry out milking in particular. Studies show that human resource management practices can help farmers to retain wage earners in farms, but the authors do not take into account changes in wage earners' work over time. Our hypothesis is that dynamic aspects in work content are crucial for wage earners, because they give them some perspective and good reasons to stay. In this paper, we analyze the evolution of permanent wage earners' work in dairy farms according to a human resource management approach. Individual interviews were carried out with farmers and permanent wage earners who work in specialized or diversified dairy farms. Five pathways of evolution of wage earners' work were identified as well five variables and categories were identified to describe the pathways of evolution according to the assignment of tasks and versatility/specialization.