Two of the most important aspects in the field of cattle reproduction and milk processing are fertility and the “casein yield” of milk. As far as cattle fertility is concerned, the critical points are to be found in the quality of the seminal material and the assessment of the laboratory parameters. With regard to milk processing and cheese manufacture, it is equally important to know the genetic component, to detect the best reproducers as far as dairy attitude is concerned and to predict, by means of milk-analysis parameters, the consequent yields obtained in industrial dairy processing. The project stems from the analysis of these “needs” that are felt more and more urgently by all components of the zootechnical sector. Nowadays the need to assess the quality/fertility of semen is considered a consequence of the genetic improvement and of the intensive exploitation of animals. With regard to dairy processing, most of the milk is used to make cheese. This kind of production is connected with territories and traditions through protection consortia and typical local production. Among the aspects which have the greatest bearing on the dairy processing yield, there is the technological quality of milk (quantity and quality of the protein component - proteins in particular), their casein fraction, the acidity and the attitude characteristics connected with the milk dynamographic parameters. This project aims at systematically and essentially dealing with the problems concerning the laboratory assessment of seminal material and at comparing, by field testing, the LDG parameters, the yield and the genetic characteristics of bulls in the Italian and Slovenian territories.