Abstract
1) In the male which is homozygous for the intersexual gene, no abnormalities appear in its sexuality, and accordingly such males occasionally used as sires.
2) As most of the sires were heterozygous for the intersexual gene in Japan, so the percentage of intersexes would be on the increase and will approach to 7.3% of occurrence in the near future. With the increase of intersexes, the homozygous recessive males also will be on the increase. If some homozygous, recessive males were used as sires in the herd, the occurrence of intersexual kids would become 14.6%, and if these were continued to mate in the herd, it would show the highest frequency of occurrence of intersexes, being attained to 25% of the total kids or 50% of the female ones.
3) To eliminate the intersexual gene, the proven sire must be used continuously for over seven generations, and when progeny test is difficult to apply, to use the horned male as the sire seems also to be the effective method of breeding.
