The bachelor's thesis includes the physiology of the digestive tract in cattle and deals with the nutrition of weaned calves. This topic includes colostrum nutrition in the first days of life after the birth of a calf. It is the most important period in nutrition in general, because it affects the production of passive immunity of calves and thus future performance. The next stage is nutrition with milk or milk compound feed. The later performance associated with the proper development of the rumen is also affected by the administration of the starter during the dairy period. The next chapters summarize calf diseases associated with dietary deficiencies, which are mainly diarrheal diseases. The final chapters suggest the treatment and preve...