Danzig, whose 181 stakes winners is the most for any North American stallion, has been retired from stud duty, according to an announcement made Tuesday by the Hancock family's Claiborne Farm near Paris, Ky..The 27-year-old stallion, who has had a profound influence on the breed, suffered from declining fertility and experienced difficulty mounting and dismounting mares. Nonetheless, he impregnated 26 of 45 mares bred to him this year and remains in good health."Danzig has been at Claiborne since 1981, and he's been very good to everyone involved with him," said farm president Seth Hancock. "I believe it's in his best interest to retire him at this time."Danzig was America's leading sire by progeny earnings from 1991 through 1993. Among active stallions prior to his retirement, he possessed the highest Average-Earnings Index, a 4.29, and the highest percentage of stakes winners from foals, 18.3%. A full 105 of his stakes winners are graded or group winners, and 21 of his offspring are champions. His top runners include Danehill, Dance Smartly, Lure, Chief's Crown, Agnes World, War Chant, Pine Bluff, and Versailles Treaty.Bred by Derry Meeting Farm and William S. Farish, Danzig (Northern Dancer--Pas de Nom, by Admiral's Voyage) won all three of his starts for Henryk de Kwiatkowski, who bought him for $310,000 at the Saratoga yearling sale.