Key	Year	Country	Breed	Number of lactations	Length of the lactations (days)	Milk yield per recorded cow (kg)	Milk per cow in 305 days (kg)	Percent of fat content (%)	Percent of protein content (%)	Calving interval (days)	Others	E-mail address of the responsible
5	2003	USA	Brown Swiss	7727	305		8310	4.08	3.33		BSCBA	rogernbs@aol.com
3	2002	USA	Brown Swiss	8065	305		8331	4.05	3.33		BSCBA	rogernbs@aol.com
4	2002	USA	Jersey								377,808 living registered cows	emetzger@usjersey.com
2	2001	USA	Brown Swiss	7695	305		8794	4.06	3.34		BSCBA	rogernbs@aol.com