NAWSA Upgrading guidelines



The North American Wensleydale Sheep Association (NAWSA) supports the development of purebred white and colored Wensleydale sheep from the crossing of specific non-Wensleydale ewes with purebred Wensleydale rams. The first generation (50%) blood bred back to a purebred Wensleydale sire produces a 75% blood. A second generation (75% blood) female, bred back to a purebred Wensleydale sire produces an 87% blood, the fourth generation produces 93%, and a fifth generation produces 96%.


The non-Wensleydale ewes used in the first cross must be registered with one of the following U.S. breed associations. No other foundation breeds shall be recognized.

  • Cotswold - American Cotswold Record Association
  • Cotswold Breeders Association, Black Cotswold Society
  • Leicester Longwool - Leicester Longwool Sheep Breeders Association
    The NAWSA strongly discourages the use of Leicester Longwools due to their low population in the U.S.
  • Lincoln - National Lincoln Sheep Breeders Association


A. There is no discrimination or separation of record keeping for colored animals. Fleece color and Codon 171 status, if known, will be noted on the registration certificate. Fleece color will be indicated by a suffix to the registration number. White-fleeced animals will be identified by the suffix “W”, and animals other than white will be identified with suffix “C”.

B. All first cross lambs must be sired by use of imported 100% Wensleydale semen. Ewe lambs from this cross will be registered as 50% Wensleydale. First cross male lambs will not be registered All rams must be at least 75% Wensleydale blood and test RR at codon 171 to be eligible for registration.

C. A sire must be registered as 75% Wensleydale or higher before any progeny are eligible for registration.

D. Lambs will be registered with their blood percentage calculated from the use of two registered parents, i.e. 50% dam crossed with a 75% sire results in a 62% lamb. If this lamb is male, it is not eligible for registration. (Refer to Item III B).

E. Rams with 75% to 95% Wensleydale blood and Ewes with 50% to 95% Wensleydale blood will be issued registration numbers with the prefix “B”.

F. An animal of either sex will be considered a purebred American Wensleydale when their percentage meets or exceeds 96% (31/32) Wensleydale blood. Sheep submitted for NAWSA purebred status must meet the breed standards set forth by the Wensleydale Longwool Sheep Breeders Association, U.K.

G. The NAWSA has set codon 171 standard for the use of imported semen, and beginning January 1, 2000, only semen from rams testing RR at codon 171 will be eligible to sire recorded or registered animals. The only exception to this rule is Upper Mill Cracker, a colored ram that has already been imported and used in the United States. This ram has tested QR at codon 171.


The sire and dam Wensleydale percentages are added together and divided by two. The resulting figure is truncated to whole numbers (e.g. 87.5 becomes 87). This number is the percent Wensleydale of the lamb.

An animal is eligible for registration as follows:

  • Ram 75-100% (must test RR at codon 171)
  • Ewe 50-100%