Both the aspects of the necessary supply level and the protein quality in the critical phase after calving are addressed.
Dairy cows cover their protein and amino acid requirements primarily from the microbial protein synthesized in the rumen. At the start of lactation, however, it is very difficult to provide dairy cows with sufficient nutrients and protein because milk production increases faster than feed intake. In the first few weeks there is often a considerable undersupply, especially of energy. Due to the close relationship between energy intake and microbial protein synthesis, the animal's protein supply is limited by the low feed intake and the resulting limited microbial protein synthesis. This applies to both conventional and organic farms. In order to avoid a protein deficiency that reduces performance and possible negative effects on animal health, increasing the protein content of the ration and also the use of protein sources with lower degradability in the rumen at the start of lactation are being intensively discussed.
In the planned research project, the influences of the protein supply level, the rumen stability of the protein and the protein source on feed intake, rumen and blood parameters, milk production, milk ingredients and milk quality at the start of lactation will be examined. Furthermore, the effects on animal health and ecologically relevant aspects are also being addressed.