Researchers at the
The gene is only lethal when it’s homozygous; that is, when both parents contribute the lethal gene variant to their offspring. However, the gene is fairly common in non-lethal combinations. Research data show the frequency of the gene in heterozygous form — where a cow carries both the lethal variant and the non-lethal variant — is as high as 50 percent among
Additional research is under way to better understand the gene, and also to develop testing procedures that will help prevent undesirable matings.