The aim of this study was to investigate the land use practiced on family farms (FF), managed under crop-livestock integration (CLP) in the watershed and to evaluate the quality of milk. 14 FFs were characterized and grouped regarding soil use (Group 1, 2 and 3) and the quality of milk was monitored during the months of May, 2010 to February 2011. In these milk samples, we evaluated the fat, protein and non-fat solids content. It can be observed that the use of soil in a crop-livestock integration system, when the grain cultivation is prioritized over the animal grazing, influences negatively the fat and protein content, on average 6.3% and 5.4%, respectively, especially during the summer. Thus, the planning of the use of soil in FF managed under CLP is essential, because the competition between the activities was reflected in the quality of milk. The FF specialized in dairy farming produces better quality milk in all annual seasons.