Inheritance of an abnormal haemoglobin haplotype in horses and its possible influence on blood values.

In a breeding experiment a stallion of the native Norwegian Trotter breed with an abnormal Hb haplotype (N) and with the Hb type BI/N, sired 6 offspring. The abnormal haplotype controls one α-chain only, having lysine at position 60 and phenylalanine at position 24. Three of the offspring received the N haplotype from the sire and the BII haplotype from the dam, whereas the other 3 offspring received BI from the sire. The BII/N horses have two Hb components after alkaline electrophoresis or isoelectric focusing with the ratio between the fast and the slow band (anodal, cathodal) being approximately 30:70. Blood value determinations did not give any definite conclusions as regards differences between horses with the abnormal Hb type and normal horses of similar age within the same breed.