Genetic Abnormality Policy
Recognizing the wide range of breeds included in animals eligible for registry in the ACA herd book and the potential introduction of genetic abnormalities from those sources the ACA will establish a listing of abnormalities to be monitored in animals and their progeny registered in the ACA herd book. From time to time, as needed, the Board of Directors will update the “Monitor” status to genetic defects of concern to ACA members. Testing requirements as outlined below will become effective once this status has been assigned.
As of July 1, 2011:
ACA registered A.I. sires will be required to be tested for genetic abnormalities recognized as monitor status by the ACA based on breed makeup before calves will be registered in herds outside that of the current owner, unless they are Expected Free by Pedigree (XX-EFP). If the AI Sire is not a registered ACA sire but is registered with another association, the sire’s status for breed relevant genetic abnormalities must be known according to their breed makeup as outlined below.
• If AI sire has Angus genetics – AM, NH, and CA status required
• If AI sire has Maine-Anjou genetics – TH and PHA status required
• If AI sire has Shorthorn genetics – TH and PHA status required
“Status” meaning free by test, expected free by pedigree, suspect or unknown with validation from respective breed association. The right to require subsequent testing based on current status is reserved by the ACA staff
If AI sire is not registered or has a parent that is not registered with any association and thereby “commercial” – AM, NH, CA, TH, and PHA testing is required regardless of breed makeup or combination.
These requirements are in addition to the long standing requirement of DNA parent validation of A.I. sires. Both the abnormality testing and parent validation testing are at the expense of the bull owner.
B. Donor Females
Embryo donor dams currently registered in the ACA Herd book will only be required to be tested for genetic defect of which they have been identified as being a Suspect (XX-S). If the embryo donor dam is not registered in the ACA herd book but is registered with another association, the donor will subject to test genetic abnormalities according to their breed association requirements or with validation from their respective breed association that such requirements have been met.
If donor is not registered with any association and thereby “commercial” – testing for AM, NH, CA, TH, and PHA is required regardless of breed makeup or combination. These requirements are in addition to the long standing requirement of DNA parent validation of donor females. Both the abnormality testing and parent validation testing are at the expense of the donor animal’s owner.
Verification of clone status is required through DNA sample submission to approved lab for testing. Once proven to be a clone, genetic abnormality status of the animal in which the DNA originated from shall be assigned to the clone. These requirements are in addition to the long standing requirement of DNA parent validation of clone animals.
Parent validation testing are at the expense of the clone animal’s owner.
B. Influential sires are identified annually as the top 25 sires for ACA registrations in each of the Chianina, Chiangus, Chimaine, Chiford and Red Chiangus Registry for each fiscal year.
• Sires to be tested must have registrations from multiple herds and have sired at least 20 animals for that year.
C. Suspect status and subsequent testing requirements may be assigned to a pedigree if a “Carrier” animal or an “Afflicted” animal is identified out of a parent verified pedigree.
D. The ACA reserves the right to conduct testing on influential AI sires for genetic abnormalities in which they are expected free by pedigree (XX-EFP) for at the expense of the ACA.
Table 1 contains the Genetic defects recognized as Monitor Status by the ACA, their respected breed of origin, and the initial test date. The breed makeup of an animal required to test will dictate those defects in which testing will be required.
Table 2 contains abnormalities monitored according to breed of origin and their respective initial test date in which the ACA reserves the right to require testing for.
TABLE 1. Abnormalities with Monitor Status
Breed Genetic Abnormality Code Test As Of:
Angus Arthrogryposis Multiplex AM December 1, 2009
Angus Neuropathic Hydrocephalus NH December 1, 2009
Angus Contractural Archnodactyly CA October 24, 2010
Maine-Anjou/ Pulmonary Hypoplasia with Anasarca PH December 1, 2009
Maine-Anjou/ Tibial Hemimelia TH December 1, 2009
Table 2. Abnormalities with Monitor Status related to other Breeds
Breed Genetic Abnormality Code Test As Of:
Hereford Hypotrichosis HT December 1, 2009
Hereford Idiopathic Epilepsey IE December 1, 2009
Red Angus Osteopetrosis OS December 1, 2009
Limonsin Protoporphyria PT December 1, 2009
5. Official Designations on Registration Certificates and other Animal Records
The ACA will initiate a genotype designation scheme for DNA tested cattle and non-tested cattle at risk of being a carrier. These designations will appear as part of the animal’s record in all documentation available to ACA members and other interested parties.
Actual Genotype designations (where XX is a two character abnormality code):
- XX-FT = free by DNA test
2. XX-C = an animal that is determined to be a carrier by DNA test or is a confirmed parent of an afflicted progeny
3. XX-A = abnormality afflicted animal (homozygous recessive)designation for an animal, entered in the ACA herd book for parentage and official record reasons, reported to the ACA, diagnosed with the abnormality represented and parent verified. Parents would receive the XX-Carrier designation.
Inferred Genotype designations (where XX is a two character abnormality code):
- XX-EFP = expected free by pedigree; both parents are free of abnormality by test or expected themselves to be free by pedigree
2. XX-S – designated on cattle with an ancestor with a XX-C designation or with a abnormality where no definitive ancestor has been identified as the initial pedigree source of the abnormality and in either case there is no intervening “Free” animal. This indicates the animal is a “Suspect” carrier until either a “Free” test result is submitted on an intervening pedigree animal or the animal itself has a test result submitted.
a. As of August 2009 no animal has been identified in the Red Angus breed as the ancestor where the mutation occurred causing the OS genetic abnormality. All Red Angus animals will be designated with an OS-S status until an OS-Free animal is found within the pedigree.
3. XX-U – designation for animal with unknown parentage and/or untested lineage.
Inferred designations will be replaced with an actual genotype designation when an animal is DNA tested.
6. Testing Laboratories
The ACA will maintain a list of laboratories that can test cattle for each ‘Monitor’ status abnormality and will accept results from those labs.
Animals must be identified by registration number at the time the sample is submitted for testing.
Breeders should be aware that ACA’s official lab for parentage, Igenity, provides abnormality testing services and if disputes occur that would require DNA parent verification of a sample it may be more cost effective for breeders to have the abnormality testing done at Igenity.
7. Testing and Shipping Fees:
Any DNA abnormality testing costs (including the diagnostic test, sample collection, preparation and shipping) associated with animals in any ACA members herd will be done exclusively at the expense of the member (unless animal falls into point 3. Testing of influential sires). A commercial producer (ACA non-member) that reports an abnormal calf (as outlined in section 8 of this policy) may be eligible for partial or full reimbursement of parentage testing costs. Abnormal calves reported by commercial producers, who’s gross pathology indicates a novel defect or one not previously monitored by ACA through this policy and has an ACA registered sire, may have parentage validated by DNA testing at the request and expense of the ACA. The request for parentage testing and funding approval will be made by the ACA Board of Directors or a designated staff member assigned such discretion. The ACA may also provide funding to pay shipping charges associated with transport of the affected calf’s carcass to the ACA’s designated diagnostic veterinary laboratory.
8. Abnormal Calf Reporting
It is the duty of ACA members who become aware of an unusual physical abnormality, either in an animal registered with the ACA or in an offspring of an animal registered with the ACA, to notify the Executive Director of the ACA by e-mail or phone as soon as possible. Working with the Executive Director or other staff member designated by the Executive Director, the member may be required to take specific steps to best position the ACA and the member to preserve as much information about the situation as possible to aid in the scientific determination of the origin of the defect. Commercial producers utilizing ACA registered parents as breeding stock who produce abnormal progeny are also encouraged to contact the ACA to assist in resolution and determination of the cause of the abnormality. If a member or veterinarian employed by the member has questions as to whether or not the abnormality is severe enough to warrant such contact, should contact the Executive Director of the ACA at once to discuss and resolve the matter. Disclosure is always the best policy. Disclosure is especially important in the case in which abnormality appears in multiple animals in the herd or the member or consulting veterinarian are unable to identify a non-genetic cause for the abnormality.
Producers are encouraged to complete an official ‘ACA Abnormal Calf Report’ and photograph or video the affected animal as soon as possible. Additionally, the owner or member should contact the ACA at once for further instructions. These instructions may include the collection of various tissues including blood for use in parent validation and the development of a pathology report by the ACA’s designated veterinary diagnostic pathologist.
9. Breeder Awareness
The ACA will use its best efforts to alert members of potential carriers in their herd and will continue educational programs to assist breeders in their efforts to eliminate the ‘monitored‘abnormalities. However, the ACA assumes no liability for overlooking potential carriers or inadvertently naming potential carriers that may in fact not be carriers in member herds.
Staff will assist breeders in developing cost effective plans to test cattle, i.e. testing an old Angus suspect cow and finding her to be clean could eliminate the necessity of testing progeny and grand progeny.
The ACA considers it an unethical practice to offer for sale a breeding animal or semen from an animal which is known to carry a deleterious genetic factor as defined by ACA without first informing the potential buyer or buyers of this fact. Any advertising, descriptive materials or pedigree initiated by the owner of a proven carrier or a potential carrier of a detrimental genetic factor as defined by ACA shall include a statement defining the deleterious factor or factors which the animal in question possesses. Any effort to conceal such information is considered to be equally unethical.
First of all, DS is not a lethal condition from a genetic inheritance standpoint. Animals known as homozygotes are cattle that carry two copies of the undesirable gene. Homozygotes of DS, referred to as “DSH” in the registry, in rare cases can be animals that function normally in a breeding herd. Most cattle that are DSH will show some outward signs of the genetic condition. In this case, the condition is a malformation of the rear pastern or pasterns (ankle area) of the animal. The important aspect of DSH is to understand that ALL progeny of DS Homozygotes will be at least Carriers of the condition…or worse.
Carriers of the DS condition, known as DSC in the registry, also need to be handled differently when mating decisions are made. Though the original mutations happened in completely separate populations, the DS condition sits on the same chromosome as Pulmonary Hyperplasia with Anasarca (PHA). Unfortunately, in the development of the embryo, it appears that the presence of a PHA Carrier can impact the phenotype (physical appearance) of a DS Carrier. In other words, if you mate a PHAC to a DSC and the unfavorable copy of both genes is passed on, the resulting calf will likely have deformed rear limbs below the hock. In each case, there is a 25% chance this will occur. As a result, a Carrier of DS could show the condition and a homozygote could appear perfectly normal. If you are testing unknown pedigrees for DS, it is highly recommended that you also test for PHA at the same time.
The following matrix details what possibilities exist when mating through, around, or away from the DS condition: F=Free, C=Carrier, & H=Homozygote.
DSF X DSF=
All progeny DSF with no outward signs of the condition.
DSF/PHAF X DSC/PHAF=
50% of the progeny will be DSC, 50% of the progeny will be DSF, rear limbs should be normal.
DSF/PHAC X DSC/PHAF=
25% of progeny will be DSC/PHAC and likely will show malformed rear limbs below the hock, 25% will be DSC/PHAF and appear normal, 25%will be DSF/PHAC and appear normal, 25% will be DSF/PHAF and appear normal.
DSC/PHAF X DSC/PHAF=
25%of the progeny will be DSH, rear limbs will likely be affected, but can also appear normal, 50% of the progeny will be DSC and rear limbs appear normal, 25% of the progeny will be DSF and rear limbs appear normal. Regardless of the outcome, if progeny of this mating are to be registered, testing will be required.
DSC/PHAC X DSC/PHAF=
Though it is unlikely a DSC/PHAC animal will be mobile enough to breed, this mating will result in a 25% chance progeny will be DSF and normal in appearance, 25% will be DSC/PHAC and likely show rear limb malformation, 25% will be DSC/PHAF and appear normal, 12.5% will be DSH/PHAC and likely show severe malformation of the rear limbs, and 12.5% will be DSH/PHAF, these animals may appear normal or have outward signs of the condition. Regardless of the outcome, if progeny of this mating are to be registered, testing will be required.
DSH X DSF=
This mating is important to understand, because 100% of the progeny will be DSC. Again, if the Carrier status for PHA comes through here too, the resulting calf will likely be affected by the condition.
DSH/PHAF X DSH/PHAF=
Though this mating is strongly not recommended, ALL progeny will be DSH/PHAF, though some progeny may appear normal in appearance.
Moving forward, the ACA will not allow registration of breeding animals that are homozygous for known genetic conditions (effective 1/1/2017). With most known conditions, this is a non-issue since a lethal condition eliminates homozygotes from the population. In the case of DS, homozygotes can appear normal. Unfortunately, its interaction with PHA and the potential penetrance into the commercial sector makes it imperative that breeders take this seriously and work hard to educate their customer base. Bottom line, breeders should avoid mating any suspect pedigrees of PHA and/or DS to one another. The technology is readily available to test for these conditions; breeders should be proactive in testing their herd and potential sale cattle.