Are kits from Stewart x Stewart matings poor breeding animals?
Norsk Pelsdyrbl 36: 271-272
Stewart x Stewart matings have been used widely during the past few years in the breeding of Topaz and Sapphire mink. As it is suspected that Topaz 22, of which both parents are carriers of the Stewart factor, are less fertile than other Topaz 22, data were obtained from 2 large mink farms. At 1 of these farms the infertility percentage was 12.5 for both Stewart Topaz and other Topaz but number of kits per mated Stewart Topaz 2 averaged only 4.42 v. 5.05 for 540 other Topaz 22.