The most common dairy cattle breed in the US is which?

• A. Holstein
• B. Jersey
• C. Guernsey
• D. Ayrshire

Answer: (A)

The idea being tested is which dairy breed is most common in U.S. dairy farming due to production efficiency. Holstein cows are the largest in size and are bred specifically for very high milk production per cow. In commercial dairy operations, milk volume is the main driver of profitability, so a breed that yields the most milk per animal becomes the default choice, leading to Holsteins becoming far and away the most widespread in the United States.

Jersey cows, while they produce milk with higher fat and protein content (which is valuable for cheese and specialty products), generally produce less total milk per cow. Guernsey and Ayrshire cows offer their own advantages but do not match Holsteins in overall volume, so they are far less common in the industry.