Published online by Cambridge University Press: 02 September 2010
The occurrence of Hb N in sheep has been investigated by means of starch gel electrophoresis.
In lambs, Hb N occurred in higher relative amounts than in adults, but not until 9 days of age. One-month-old lambs often showed an Hb N content as high as 10–30%.
Haemoglobin N was observed most in sheep of phenotype AA, less in those of type AB and was found to be absent in BB animals. It was also provoked experimentally by bleedings in sheep of types AA and AB but not in those of type BB.
Comparisons between breeds showed differences in the expression of Hb N. It occurred most regularly in Old Norwegian sheep (Spæl), but usually in concentrations of less than 1%. Hb N was, however, also found in other Norwegian breeds, in Cheviots and in Spanish sheep but not in sheep of the Oxford Down breed.
In two flocks of Spæl and Dala sheep where frequent bleedings were made, Hb N was observed at all times of the year.