Originally from the Isle of Guernsey, Guernseys debuted in the U.S. in 1840. They were developed by selecting the best bloodlines of the ancient Alderney and Froment du Leon breeds from France. Guernseys are known for the golden color of their milk due to the high concentration of beta carotene and adaptability to various climates. They can now be found in herds from southern Florida to central Alaska and everywhere in between.

Courtesy of the American Guernsey Association

American Guernsey Association represents the U.S. Guernsey breed.

Learn about Guernsey activities, programs and services at

National Production Averages

The average annual milk production for U.S. Guernsey cows is well-documented by NDHIA through milk recording.

Genetic Conditions

Guernseys do not have any known undesirable genetic recessives.

Genomic Testing

The American Guernsey Association provides genomic and parentage testing for registered Guernsey cattle upon request.

Total Merit Index: PTI

U.S. Guernseys are ranked on the Production Type Index (PTI). Traits in this index include: 

  • Protein yield
  • Fat yield
  • Udder Composite
  • Foot and Leg Composite
  • Productive Life
  • Daughter Pregnancy Rate
  • Cow Livability
  • Stature
  • Strength

The Guernsey PTI formula was last updated in April 2020.