Curly Calf Syndrome

Arthrogryposis Multiplex

History

  • Medical name- Arthrogryposis Multiplex (AM)
  • Genetic defect in mainly Angus cattle but also found in other breeds such as charolais
  • Traced Back to the GAR Precision 1680 bloodlines of Gardiner Angus Ranch in Ashland, Kansas
  • First case was reported in 2002

Diagnosis in Newborns

  • Contraction of the joints of front and/or back limbs at birth
  • rigid, hyperextended limbs
  • Abnormal spine- twist or curvature
  • Small and lack muscle
  • Stillborn or die shortly after birth
  • Other birth defects often appear along with curly calf syndrome like cleft palate
Curly Calf Syndrome

Why Arthrogryposis Multiplex became a problem

According to Dr. Laurence Denholm, Arthrogryposis Multiplex would not have been well known if the carrier sire, GAR Precision 1680, had not been so well known and widely used for his superior performance carcass traits.

Other Known Angus Bull Carriers


  1. Pantrock Extra 295-2
  2. Clearwater Precision 1309
  3. CCAR Defined W045
  4. Willow Creek Precision
  5. Riverside Strategy 7253
  6. Leachman 616-1885-9028

Genetic Transmission

  • Autosomal recessive in angus breeds
  • Not sex linked
  • one simple recessive gene
  • affected cattle have two copies of the AM gene (AMA)
  • Carrier cattle have one copy of the AM gene (AMC)
  • Animals testing free of AM do not have an AM gene (AMF)
  • Researched by Dr. Jonothan E. Beever and Dr. David Steffen in 2008

Genotypes

When breeding a carrier bull (Cc) to a carrier cow (Cc) the genotypes are as follows:


  • 25%- Homozygous dominant normal genes (CC)
  • 50%- Heterozygous normal x recessive AM gene (Cc)
  • 25%- Homozygous recessive AM gene (cc)
  • Only homozygous recessive shows the symptoms of AM
  • heterozygous genotypes are carriers and homozygous normal is AM free
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Other Causes of disease

  • Ingestion of toxic lupine plants between 40 and 70 days of gestation
  • Utero infection of Bluetongue virus
  • Utero infection of Akabane virus

Eradication Methods

  • DNA testing is the only way to determine whether the animal is a carrier
  • American Angus Association and Red Angus Association do not allow carrier bulls or heifers to be registered
  • Affected animals do not usually survive
  • DNA test is $20- $29 dollars per animal
  • Tests can be done with whole blood, blood on FTC card, hair, semen, and tissue samples depending on the company.

Opinion

Although AM carrier bulls and heifers are not allowed to be registered as of 2011, there are still thousands of registered animals that are being bred. Carrier animals should only be used for slaughter or only be allowed to be crossed to non-Angus breeds. This would speed up the process of complete eradication.