Haplotypes Affecting Fertility
Genomic technology has proven to be a powerful tool in the area of genetic advancement. It has provided dairy producers avenues to greater genetic progress through use of young bulls with higher genetic levels. In addition to deriving genomic PTAs, research is ongoing to describe and explain the function of specific genes or chromosome segments, also referred to as haplotypes. By better understanding how haplotypes function, there is greater opportunity to utilize this information in breeding decisions.
USDA researchers have identified 10 haplotypes that appear to inhibit fertility when these haplotypes occur in a homozygous state; in other words, when a specific DNA sequence is inherited from both parents. Five of these haplotypes are found in the Holstein breed, two occurring in each of the Jersey and Brown Swiss breeds, and a newly-discovered haplotype in the Ayrshire breed. Carriers of the haplotypes affecting fertility are noted on the bull's individual web page in the online sire catalog and MPG.