Haplotypes impacting fertility With our growing knowledge about the bovine genome, experts have predicted for some time that we’d likely discover numerous cattle genetic defects. Human genetic researchers estimate that we each carry four or five genetic defects. It’s reasonable to expect that these exist at a similar level in cattle. USDA researchers along with international collaborators have identified five Holstein haplotypes that appear to cause embryo loss or stillbirths when these haplotypes exist in the homozygous state. These genetic conditions have not been directly observed and we do not know the exact genetic or biological cause of why the embryos or fetuses are not viable. Because of this, they’ve been given simple names of Holstein Haplotype 1 (HH1), Holstein Haplotype 2 (HH2), Holstein Haplotype 3 (HH3), Holstein Haplotype 4 (HH4) and Holstein Haplotype 5 (HH5). These haplotypes appear to have a recessive mode of inheritance where animals with zero or one copy of the haplotype are completely normal. Those that inherit two copies of the haplotype are lost as embryos or are stillborn. The impacts of these haplotype vary and are dependent on their frequency in the population and at what stage of gestation the pregnancies are lost. HH1, HH2, HH3 and HH5 all have similar frequencies (4.5%, 4.6%, 4.7% and 4.8%, respectively). HH4 exists at a much lower frequency of 0.7 percent. It’s important to realize that the negative impact of these haplotypes is already accounted for in the routinely published sire conception rate (SCR) evaluations and daughter pregnancy rate (DPR) genomic evaluations. So, if you are using these traits in selecting your A.I. sires, you’re already avoiding or compensating for these new genetic conditions. The haplotypes each represent a distinct and unique genetic condition. They are not related to each other. The haplotypes have no impact when a bull that is heterozygous for HH1 is mated to a cow that is heterozygous for HH2. The risk is only experienced when animals are heterozygous for the same haplotype. Select Mating Service (SMS) is an excellent tool for managing these genetic conditions. By using the SMS program, herds with at least one generation of pedigree information on their cows can use heterozygous bulls with less than 1 percent chance of lost pregnancies from known conditions.
Code Number
Select Sires' HaplOTYPE Carriers
Code Name
Haplotype
250HO1117 Caption 7HO12420 Miksa 7HO12589 Jacoby 7HO13165 Ripper 7HO10375 Mr Mudd 7HO10406 Dashawn 7HO10429 Montney 7HO10585 Helix 7HO10702 Excel 7HO10723 Spur 7HO10884 Avery 7HO11279 Moonboy
HH3C HH3C HH5C HH3C HH3C HH2C HH3C HH5C HH4C HH3C HH3C HH3C
Code Number
Code Name
7HO11283 Mayfield 7HO11402 Tavir 7HO11424 Offie 7HO11488 Branson 7HO9222 Shot 7HO9281 Bigshot 7HO12107 Loar 7HO12131 Mcgirt 7HO12175 Wonka 7HO12310 Bankroll 7HO12322 Delfino 7HO12357 Penley
Haplotype HH3C HH3C HH2C HH5C HH5C HH3C HH5C HH3C HH3C HH3C HH2C HH3C
Code Number
Code Name
7HO12387 Madron 7HO12409 Mirage-Red 7HO12431 Ridge-P 7HO12440 The Dude 7HO12441 Maven 7HO12443 Plus-PP 7HO12477 Radman 7HO12518 Snowboy 7HO12533 Hotshot 7HO12555 Mansfield-P 7HO12588 Oh Boy-PP 7HO13035 Modesto
Haplotype HH3C HH3C HH5C HH3C HH5C HH2C HH3C HH3C HH5C HH3C HH3C HH5C
Haplotype for Cholesterol Deficiency (HCD) At the 2015 Interbull Annual Meeting, German researchers reported that they had discovered a new genetic defect in Holstein dairy cattle. The defect, Haplotype for Cholesterol Deficiency (HCD), causes young calves to die if homozygous for HCD. Unlike previous haplotypes that cause early embryo loss, this haplotype creates a greater economic loss. Even though calf survival has a low heritability, Paul VanRaden of the USDA Animal Genomics and Improvement Laboratory (AIPL), recommends avoiding recessive defects by using sound selection and mating programs. The defective haplotype traces back to Maughlin Storm. Storm’s sire and maternal grandsire do not carry HCD. This suggests that HCD is a result of a recent mutation that first appeared in Storm or his dam. Influential descendants of Storm that also carry HCD are Stormatic, September Storm and Goldwyn. Unfortunately, the haplotype carrying the defect is difficult to track. Part of the difficulty is caused because descendants of Comestar Laurie Sheik and Comestar Outside appear to have the HCD haplotype but do not appear to produce affected calves. For animals that have the haplotype and have both Storm and Outside in their pedigrees, it’s difficult to know whether they transmit the defective condition or not. Animals that don’t have the haplotype will be labeled as non-carriers. Animals that have the haplotype and it’s determined the haplotype came from Storm will be labeled as carriers. Those animals that have the haplotype and it’s determined the haplotype came from Outside will be labeled as non-carriers. Those animals that have the haplotype and it can’t be determined whether it came from Storm or Outside will be labeled as suspect.
Select Sires' HaplOTYPE Carriers Code Number
76
Code Name
250HO 1123 Motivator 7 HO 10848 Grafeeti 7 HO 10884 Avery 7 HO 11163 Ladd P-Red 7HO11703 ARMANI 7 HO 9264 Dempsey 7 HO 12170 Corey 7 HO 12580 Bosa 7 HO 12626 Manny-Red 7 HO 13276 Bowen
Haplotype HCDC HCDC HCDC HCDC HCDC HCDC HCDC HCDC HCDC HCDS