The study looked at how specific genes in cows affect the proteins found in their milk. They analyzed milk samples from Fleckvieh and Braunvieh cows to see how different gene variations influenced the levels of various milk proteins. The researchers found that certain gene variations had a significant impact on the production of casein proteins, which are important components of milk. They also discovered that the genetic variations had similar effects in both breeds of cows. Overall, the study showed that genetics play a significant role in determining the composition of milk proteins in cows.