The USDA has identified five haplotypes - groups of SNP markers in adjacent positions on the chromosome and usually inherited together - that have a negative effect on conception rate. It is assumed a mating inheriting the same haplotype (homozygous) from both parents results in failed conception or early embryonic loss. For that reason, the USDA has provided the haplotype carrier status for individual animals.
According to the USDA, it is important to note the haplotypes' impact is already reflected in Sire Conception Rate, Daughter Pregnancy Rate and Lifetime Net Merit; attempts to eradicate animals with undesirable haplotypes is not recommended due to the economic impact of these animals; eradication is not practive given likelihood more undesirable haplotypes will be found; avoiding sires with these haplotypes will lead to significant economic loss in other important traits; and computerized mating programs are simple, inexpensive solutions for avoiding affected matings.
For more information, read the articles below by Kent Weigel (University of Wisconsin) and Angie Coburn (Genex). Also view the lists indicating the haplotype status of Genex sires.
Haplotypes Affecting Fertility and their Impact on Dairy Cattle Breeding Programs
By Kent A. Weigel, University of Wisconsin (Available in Español: Click Here)
Haplotypes Affecting Fertility
By Angie Coburn, AVP-Dairy Genetics, Genex (Available in Español: Click Here)
Haplotype Listing by Bull for Active Genex/CRI Sires
(Active bulls listed by breed and then reverse Lifetime Net Merit)
Posted April 2012
Haplotype Carrier Listing for All Genex/CRI Sires
(Carriers listed by breed and then numerically by NAAB code)
Posted April 2012
