Partial albinism (heterochromia irides) in Black Angus cattle

Abstract

A new coat colour defect (heterochromia irides) is described in Black Angus cattle. The coat colour is brownish. The iris is light, two-coloured, with an outer faintly brown ring and an inner blue ring. The fundus of the eye is albinotic. The trait does not impair the ability to reproduce although photophobia is present. Gestation length and birth weights were not affected in F1 Hereford × Angus progeny. All progeny which resulted from this mating proved normal in every respect upon physical examination. The 52 normal F1 calves resulting from this mating suggest that this trait is transmitted as a simple autosomal recessive. Breeding an affected bull to three affected dams resulted in three affected calves (one female, two males). The F1 females resulting from similar matings must be considered viable commercial breeding cattle when due care is exercised in future sire selection.