Post by rockmillsherefords on Jun 5, 2020 15:11:31 GMT -6
June 5, 2020
To the Membership of the American Hereford Association:
The American Hereford Association (AHA), in collaboration with Dr. David Steffen and Dr. Jessica
Petersen at the University of Nebraska-Lincoln (UNL), have discovered a novel defect in Hereford cattle
called Mandibulofacial Dysostosis (MD). This genetic defect is considered autosomal recessive,
meaning an affected calf must have two carrier parents.
The AHA was first contacted in early March 2020 about a calf with facial deformities and per AHA rules
the case was referred to Dr. Steffen at UNL for diagnosis. Additional calves were reported from two
other herds in the following weeks. The following are findings from Dr. Steffen and Dr. Petersen:
• Four Hereford calves were presented in March and April of 2020 with unusual defects of the face
and jaw. Autopsy, evaluation of breeding records and genotyping was a cooperative effort.
• The calves originated from three herds, each in a different state, making an environmental cause
unlikely. Autopsy of the calves revealed shared, unique abnormal facial features. Breeding records
demonstrated a common sire in the pedigree of both the sire and dam of each affected calf. The
similarity in the defect among the calves and pedigree analysis together suggested a new
deleterious recessive mutation may exist.
• The anatomic features overlap with a variety of other facial defects and can include cleft palate,
brachygnathia (short jaw) and camplygnathia (crooked jaw or face). These are variably present in
affected calves (Figures 1-3) and are sometimes dramatic (Figure 3). The unique and consistent
hallmarks of the condition include unusual bilateral skin tags just behind the corner of the mouth
(Figures 1-3). These tags are attached to an unusual bone formation. There may be additional skin
tags near and/or below the ears. A ridge of Meckel’s cartilage, a structure usually present only
during embryonic development, is retained in these calves and attaches to the skin tag. This
cartilage is encased in bone as it is followed from the skin tag toward the base of the ear. This bone
attaches specifically to the zygomatic process of the temporal bone (just above the articulation of
the jaw). The calves’ ears are sometimes slightly small and floppy. Muscles of the jaw are
underdeveloped and calves may have an elongate oral opening appearing as an exaggerated smile.
The nursing reflex is present, but nursing is not vigorous. Calves with the additional cleft palate,
severely shortened or crooked jaws are debilitated in ability to nurse. Calves with the defect are
live born but are not able to thrive.
Utilizing whole genome sequencing, the research team at UNL identified a causative mutation from the
animals submitted and the animals directly related to the affected calves. Next, UNL developed a singlemarker
assay to test additional animals to validate the test and to continue to verify the implicated genetic
line. The team at UNL is working with Neogen® to develop a commercially available test so breeders can
submit DNA for testing or have prior samples on file at the AHA tested. This test will be a standalone test
and is not part of any current genotype panels on which animals have been tested. The AHA expects this
test will be available in the coming months for breeders to utilize.
11500 N. Ambassador Dr., Ste. 410 | Kansas City, MO 64153 | P: 816-842-3757 | F: 816-243-1314 | aha@hereford.org
The research team at UNL is willing to test specific animals utilizing their own test to mitigate risk and to
aid in identifying breaks in pedigree relationship transmission from established carrier animals. However,
to ensure quality control, only artificially inseminated (AI) permitted bulls that have semen will be
allowed for initial testing. Since this is a single-marker test, parent verification is not possible on the
assay developed at UNL making it imperative parentage confirmation already be completed. For testing
efficiency, UNL has requested only semen straws be submitted and that samples be submitted through the
AHA for batching and verification.
To test herd bulls, breeders need to contact the AHA via phone or email with bulls they plan to submit.
Semen straws must be shipped to the AHA. UNL will not be able to accept semen submission directly
from breeders because this test is completed outside the scope of UNL’s regular diagnostic services in
cooperation with research. Semen straws must be shipped thawed and with some form of protection with
a frozen gel pack or frozen water bottle to: American Hereford Association, Attn: Shane Bedwell, 11500
N Ambassador Dr., Suite 410, Kansas City, MO 64153. Place the cold pack inside a ziplocked or similar
bag to prevent condensation from damaging the paperwork, samples and shipping containers.
The AHA suggests first testing impacted pedigrees in order to help identify breaks in transmission down
the pedigree, but all AI-permitted bulls with semen may be submitted for testing. Breeders should expect
typical turnaround time for genotyping when submitting for MD testing at this time.
To aid in determining which bulls to test, breeders can utilize the potential defect carriers report generated
through MyHerd, but understand this tool constantly updates. Therefore, the AHA recommends breeders
run the report periodically over the next couple months as pedigree relationships will be broken as more
animals are tested and identified as either carriers or free from the condition, which could implicate
animals in other herds. Breeders can find animals that have been tested for MD at Herfnet.com.
The AHA is publishing 11 animals that have been identified as a carrier for MD and that are directly
involved in the cases submitted to UNL for research. These 11 animals are listed below and will be
identified on Herfnet.com as Mandibulofacial Dysostosis Carrier (MDC).
SHF WONDER M326 W18 ET 42991698 MDC
NJW 73S W18 HOMEGROWN 8Y ET 43214852 MDC
NJW 73S W18 HOMETOWN 10Y ET 43214853 MDC
SHF Access Y90 43379349 MDC
K KING 400 43565031 MDC
GO MS ACCESS C81 43584089 MDC
GO MS ACCESS E24 43796704 MDC
GO KING E43 43796809 MDC
RVF SWEET PEA SHES REAL QUIET 43810058 MDC
GO KING F42 43910077 MDC
PERKS CATO RUMMY 8011 ET 43937392 MDC
11500 N. Ambassador Dr., Ste. 410 | Kansas City, MO 64153 | P: 816-842-3757 | F: 816-243-1314 | aha@hereford.org
In research of identifying where the mutation occurred the following sires have been tested as being free
for MD and consequently will be listed as Mandibulofacial Dysostosis Free (MDF) on Herfnet.com.
The following three sires will be listed as MDF.
KCF BENNETT 3008 M326 42361822 MDF
MM RSM STOCKMASTER 512 23839472 MDF
SHF INTERSTATE 20X D03 23812935 MDF
If a suspect calf is presented, please alert the AHA or Dr. Steffen at the Nebraska Veterinary Diagnostic
Center. Both parties can assist with proper diagnosis and parentage verification for this or any other
abnormalities you may encounter. If you identify suspect calves in your herd, be alert for testing
availability as screening at-risk animals in the breeding population is critical to prevent future losses.
The AHA appreciates your cooperation with reporting cases of affected calves in order to identify this
novel defect. Truly, it was a team effort between the breeders, UNL and the AHA staff in quickly
addressing this genetic condition. Fortunately, with new technology and advancements, breeders can
work around this defect to continue to breed carrier animals if they so choose, opposed to totally culling
affected genetic lines. The AHA will update the membership as more information becomes available on
the commercial test at Neogen. We appreciate our strong membership and thank breeders in advance for
their patience and cooperation.
Sincerely,
Jack Ward
Executive Vice President
American Hereford Association
Shane Bedwell
COO and Director of Breed Improvement
American Hereford Association
To the Membership of the American Hereford Association:
The American Hereford Association (AHA), in collaboration with Dr. David Steffen and Dr. Jessica
Petersen at the University of Nebraska-Lincoln (UNL), have discovered a novel defect in Hereford cattle
called Mandibulofacial Dysostosis (MD). This genetic defect is considered autosomal recessive,
meaning an affected calf must have two carrier parents.
The AHA was first contacted in early March 2020 about a calf with facial deformities and per AHA rules
the case was referred to Dr. Steffen at UNL for diagnosis. Additional calves were reported from two
other herds in the following weeks. The following are findings from Dr. Steffen and Dr. Petersen:
• Four Hereford calves were presented in March and April of 2020 with unusual defects of the face
and jaw. Autopsy, evaluation of breeding records and genotyping was a cooperative effort.
• The calves originated from three herds, each in a different state, making an environmental cause
unlikely. Autopsy of the calves revealed shared, unique abnormal facial features. Breeding records
demonstrated a common sire in the pedigree of both the sire and dam of each affected calf. The
similarity in the defect among the calves and pedigree analysis together suggested a new
deleterious recessive mutation may exist.
• The anatomic features overlap with a variety of other facial defects and can include cleft palate,
brachygnathia (short jaw) and camplygnathia (crooked jaw or face). These are variably present in
affected calves (Figures 1-3) and are sometimes dramatic (Figure 3). The unique and consistent
hallmarks of the condition include unusual bilateral skin tags just behind the corner of the mouth
(Figures 1-3). These tags are attached to an unusual bone formation. There may be additional skin
tags near and/or below the ears. A ridge of Meckel’s cartilage, a structure usually present only
during embryonic development, is retained in these calves and attaches to the skin tag. This
cartilage is encased in bone as it is followed from the skin tag toward the base of the ear. This bone
attaches specifically to the zygomatic process of the temporal bone (just above the articulation of
the jaw). The calves’ ears are sometimes slightly small and floppy. Muscles of the jaw are
underdeveloped and calves may have an elongate oral opening appearing as an exaggerated smile.
The nursing reflex is present, but nursing is not vigorous. Calves with the additional cleft palate,
severely shortened or crooked jaws are debilitated in ability to nurse. Calves with the defect are
live born but are not able to thrive.
Utilizing whole genome sequencing, the research team at UNL identified a causative mutation from the
animals submitted and the animals directly related to the affected calves. Next, UNL developed a singlemarker
assay to test additional animals to validate the test and to continue to verify the implicated genetic
line. The team at UNL is working with Neogen® to develop a commercially available test so breeders can
submit DNA for testing or have prior samples on file at the AHA tested. This test will be a standalone test
and is not part of any current genotype panels on which animals have been tested. The AHA expects this
test will be available in the coming months for breeders to utilize.
11500 N. Ambassador Dr., Ste. 410 | Kansas City, MO 64153 | P: 816-842-3757 | F: 816-243-1314 | aha@hereford.org
The research team at UNL is willing to test specific animals utilizing their own test to mitigate risk and to
aid in identifying breaks in pedigree relationship transmission from established carrier animals. However,
to ensure quality control, only artificially inseminated (AI) permitted bulls that have semen will be
allowed for initial testing. Since this is a single-marker test, parent verification is not possible on the
assay developed at UNL making it imperative parentage confirmation already be completed. For testing
efficiency, UNL has requested only semen straws be submitted and that samples be submitted through the
AHA for batching and verification.
To test herd bulls, breeders need to contact the AHA via phone or email with bulls they plan to submit.
Semen straws must be shipped to the AHA. UNL will not be able to accept semen submission directly
from breeders because this test is completed outside the scope of UNL’s regular diagnostic services in
cooperation with research. Semen straws must be shipped thawed and with some form of protection with
a frozen gel pack or frozen water bottle to: American Hereford Association, Attn: Shane Bedwell, 11500
N Ambassador Dr., Suite 410, Kansas City, MO 64153. Place the cold pack inside a ziplocked or similar
bag to prevent condensation from damaging the paperwork, samples and shipping containers.
The AHA suggests first testing impacted pedigrees in order to help identify breaks in transmission down
the pedigree, but all AI-permitted bulls with semen may be submitted for testing. Breeders should expect
typical turnaround time for genotyping when submitting for MD testing at this time.
To aid in determining which bulls to test, breeders can utilize the potential defect carriers report generated
through MyHerd, but understand this tool constantly updates. Therefore, the AHA recommends breeders
run the report periodically over the next couple months as pedigree relationships will be broken as more
animals are tested and identified as either carriers or free from the condition, which could implicate
animals in other herds. Breeders can find animals that have been tested for MD at Herfnet.com.
The AHA is publishing 11 animals that have been identified as a carrier for MD and that are directly
involved in the cases submitted to UNL for research. These 11 animals are listed below and will be
identified on Herfnet.com as Mandibulofacial Dysostosis Carrier (MDC).
SHF WONDER M326 W18 ET 42991698 MDC
NJW 73S W18 HOMEGROWN 8Y ET 43214852 MDC
NJW 73S W18 HOMETOWN 10Y ET 43214853 MDC
SHF Access Y90 43379349 MDC
K KING 400 43565031 MDC
GO MS ACCESS C81 43584089 MDC
GO MS ACCESS E24 43796704 MDC
GO KING E43 43796809 MDC
RVF SWEET PEA SHES REAL QUIET 43810058 MDC
GO KING F42 43910077 MDC
PERKS CATO RUMMY 8011 ET 43937392 MDC
11500 N. Ambassador Dr., Ste. 410 | Kansas City, MO 64153 | P: 816-842-3757 | F: 816-243-1314 | aha@hereford.org
In research of identifying where the mutation occurred the following sires have been tested as being free
for MD and consequently will be listed as Mandibulofacial Dysostosis Free (MDF) on Herfnet.com.
The following three sires will be listed as MDF.
KCF BENNETT 3008 M326 42361822 MDF
MM RSM STOCKMASTER 512 23839472 MDF
SHF INTERSTATE 20X D03 23812935 MDF
If a suspect calf is presented, please alert the AHA or Dr. Steffen at the Nebraska Veterinary Diagnostic
Center. Both parties can assist with proper diagnosis and parentage verification for this or any other
abnormalities you may encounter. If you identify suspect calves in your herd, be alert for testing
availability as screening at-risk animals in the breeding population is critical to prevent future losses.
The AHA appreciates your cooperation with reporting cases of affected calves in order to identify this
novel defect. Truly, it was a team effort between the breeders, UNL and the AHA staff in quickly
addressing this genetic condition. Fortunately, with new technology and advancements, breeders can
work around this defect to continue to breed carrier animals if they so choose, opposed to totally culling
affected genetic lines. The AHA will update the membership as more information becomes available on
the commercial test at Neogen. We appreciate our strong membership and thank breeders in advance for
their patience and cooperation.
Sincerely,
Jack Ward
Executive Vice President
American Hereford Association
Shane Bedwell
COO and Director of Breed Improvement
American Hereford Association
