Control of Cotton Fur in Mink by Dietary Iron

Abstract

Two experiments were designed to test the effect of adding dietary iron to fish type diets on the development of cotton pelts in mink. In the first experiment 352 mink kits consisting of equal numbers of males and females were divided into four treatment lots. Four levels of ferrous fumarate (0, 440, 880 and 1760 mg. per kg. of feed) were fed from weaning in July to pelting in December. None of the kits receiving the iron developed cotton pelts, whereas 22% of the controls did. In the second experiment 128 females were allotted to 16 outcome groups and randomly assigned to eight treatments in a factorial design. The treatment variables and the levels tested were: ferrous fumarate, 0 and 440 mg. per kg. of feed; the antioxidant BHT, 0 and 123 mg. per kg. of feed; and fur seal meat 0 and 10% of the diet. The females were continued on experiment throughout the breeding, gestation and lactating periods. The first 41 kits weaned from each treatment were continued on the treatments until pelting. Development of cotton pelts was again prevented by the iron salt. Steatitis was prevented by BHT and was reduced somewhat by the substitution of fur seal meat for salmon Tieads. No significant treatment effects on kit production and growth were obtained in the experiments.