Holstein Association USA recognizes the importance of identifying heritable, sometimes undesirable, unique genes in Holstein cattle, to provide breeders with the tools they need to make informed breeding decisions. Use the free tools below to learn more about genetic testing and research animals to see if they have been tested as carriers or non-carriers for various traits, or may potentially be a carrier based on their pedigree. For more information, call Holstein Association USA customer service at 800.952.5200.

USDA researchers have recently discovered three haplotypes impacting fertility in the Holstein breed. A haplotype is a combination of alleles (DNA sequences) at different locations on a chromosome that are transmitted together as a group (linked). Referred to as HH1, HH2 and HH3, these haplotypes are believed to cause embryonic or fetal death when present in homozygous form, i.e., the offspring inherits the haplotype from both the sire and dam. In a herd, this would appear as if a cow did not conceive, resulting in greater days open and lower conception rates. Researchers have found that these haplotypes never occur in homozygous form amongst any living animal (that had their genome tested; the group researchers studied). That scenario is highly unlikely based on population probabilities, unless affected animals did not survive to birth.

Holstein Association USA encourages breeders to pay attention to pedigrees, work to learn the status of their animals, be mindful of the status of service sires in their herd, and avoid mating carriers of individual haplotypes to carriers of the same haplotype. It is possible for fertility rates to be improved by carefully selecting matings to avoid the chance of potential offspring inheriting the lethal version of a haplotype impacting fertility.

• Read more detailed information about the haplotypes impacting fertility and
  how breeders can use the information to make more informed mating decisions.
  
  
• Haplotypes Affecting Fertility and their Impact on Dairy Cattle Breeding Programs, by Dr. Kent A Weigel

Click photo to watch a recording of Holstein USA's webinar about Haplotype's Impacting Fertility, presented by Dr. Roger Shanks (8/24/2011)

To all Holstein breeders, owners, lessees, and enthusiasts:

We are publishing new information on haplotypes impacting fertility. The article titled, "Interpreting and Utilizing New Holstein Genetic Information," along with the article from Dr. Kent Weigel, University of Wisconsin-Madison, titled, "Haplotypes Affecting Fertility and their Impact on Dairy Cattle Breeding Programs," provide excellent background information.

A complete list of all animals that are known carriers or tested non-carriers of these haplotypes impacting fertility, at this time, can be found below.

All animals are listed alphabetically by name; animals with a number as the start of their prefix will be listed under "Numeric." A list of all males and females that have been identified as carriers is available beneath the general listings for quick reference.

Tested Bull Haplotype Status ( pdf format)
Numeric & A	G	M	T
B	H	N	U
C	I	O	V
D	J	P & Q	W
E	K	R	X, Y & Z
F	L	S
List of all carrier bulls

 

Tested Female Haplotype Status ( pdf format)
Numeric & A	G	M	T
B	H	N	U
C	I	O	V
D	J	P & Q	W
E	K	R	X, Y & Z
F	L	S
List of all carrier females

Answers to Frequently Asked Questions about Brachyspina (pdf)

Bulls Recorded as Carrier (BY) or Tested Free (TY) of Brachyspina
To reduce download/viewing time of the pdf files, we are providing the list in sections, 
ordered alphabetically by bull's long name, as follows:

A-E or a numeric character
F-L
M-Q
R-Z

The test is based on a specific set of DNA-variation which is co-inherited with the disease. As a result, the indirect test predicts the status of the actual mutation. Due to the nature of linked marker test, there is a slight chance that the result of the test changes when the mutation is found in the future.