1. Holstein: The most popular breed in the world, known for their black and white markings and high milk production.
2. Jersey: Smaller than Holsteins, known for their rich, golden-colored milk with high butterfat content.
3. Guernsey: Similar to Jerseys, but with a fawn-colored coat and even higher butterfat content.
4. Ayrshire: Known for their red and white markings, Ayrshires produce a good amount of milk with a balance of fat and protein.
5. Brown Swiss: Large cows with a brown coat, they produce a high volume of milk with good butterfat content.