Genetic Conditions

Weaver, Spiderleg, SDM and SMA are recognized abnormalities in Brown Swiss cattle. They are caused by simple recessive genes and declared to be undesirable genetic recessive factors.

Weaver  (W) : Bovine Progressive Degenerative Myeloencephalopathy
Spiderleg (A) : Syndrome of Arachnomelia and Arthrogryposis; SAA
SDM  (D) : Spinal Dysmyelination
SMA (M) : Spinal Muscular Atrophy

These abnormalities occur as results of defects in genetic code which have been passed on to offspring as recessives. They can only be passed on through genetic inheritance and can only be controlled through proper breeding management.

In accordance with the Brown Swiss Association policy on abnormalities, the bulls listed in the attached .pdfs have been identified as carriers of genetic recessive genes. Any publication or the use of the registered name of these bulls must include the relevant suffix. Anyone offering for sale semen from designated carriers or embryos from parents of known carriers must make available such facts to potential buyers.

Abnormality Procedure

1. Call the Brown Swiss Association to file Abnormality Report & determine the next step. Not all cases will be asked to send samples to the lab. In most cases, DNA tests will be done to perform parentage on calf and dam.

2. Pull 50 clean hair strands from tail (if calf is dying) to send to BV Labs for Parentage Testing (DNA).  Note:  The bulb or root must be attached to the hair.   If dam has not been DNA tested, a DNA sample from dam is also needed. (If animal is alive, contact office for FTA blood card instead of using hair.) Prior to sending hair to BV Labs, please contact Brown Swiss Association at 608-365-4474.  

BV Labs                                                 Courier  BV Labs                                     
PO Box 670, PMB 19                                402 Center Street, PMB 19
Lewiston, NY 41092-1604                          Lewiston, NY 14092-1604
                                                            1-716-425-1359

Direct to lab in Canada BV Labs (Bureau Veritas Laboratories)
335 Laird Road, Unit 2
Guelph, ON  N1G 4P7
Canada
1-519-836-2400  or  Toll-Free  1-877-706-7678

3. IF SMA suspected - contact your veterinarian to send brain & spinal cord for diagnosis to:
Also send pedigree & abnormality report provided by BSCBA.

NE Veterinary Diagnostic Lab
University of Nebraska - Lincoln - East Campus Loop & Fair Street
Lincoln, NE 68583
PH: 402-472-4533
FAX: 402-472-3094

FOR PACKING BRAIN & SPINAL CORD: Cut off center so they can be removed when calf dies and save in formaldehyde for shipment to NE lab. Slide cross sections may also be sent, but please call the Nebraska Diagnostic lab prior to sending slides.