2022 USSA Member Directory

SUFFOLK RESOURCE LIBRARY

Spider Lamb Syndrome GENETIC ABBREVIATIONS: NN – Non-Carrier, free of spider gene NS – Carrier of spider gene SS – Exhibits Spider gene

This condition was first found in Suffolk sheep in the 1980s. Thanks to genetic selection by Suffolk breeders, this is no longer a commonly seen condition.

SIRE (NS) N S

Thompson and Dittmer, 2008

N NN NS N NN NS

Scrapie GENETIC ABBREVIATIONS: RR – Least susceptible, and all offspring will have at least one “R” gene QR – Least susceptible (but some offspring can inherit the “Q” gene) QQ – Most susceptible if exposed (note: there is no difference in susceptibility between RR and QR - they only need one copy to be less susceptible. There is a rare variant of Scrapie that can affect sheep with an R gene, which is why we technically can’t call it resistant) WHAT IS IT - Fatal brain disease affecting the nervous system in sheep and goats. WHY IS IT A CONCERN - Clinical signs are progressive and fatal once they develop. Infected animals may not become ill for years. There is no treatment. Dwarfism GENETIC ABBREVIATIONS: FF – Free, non-carrier FD – Carrier DD – exhibits dwarf gene WHAT IS IT - Recessive defect causing severe skeletal shortening of the limbs. WHAT IS IT - Inherited disorder associated with severe skeletal deformities. Affected animals have long splayed (bent) legs and exhibit twisted spines, flattened ribs and facial defects. WHY IS IT A CONCERN - Lambs have trouble standing and rarely survive beyond 6 months of age. There is no treatment. MANAGEMENT - Genetic testing is available to determine if the sheep is a carrier of the gene. Select resistant animals.

SIRE (NN) N N

SIRE (NS) N S

N NN NN N NN NN

N NN NS S NS SS

MANAGEMENT - Biopsy of the brain or lymphoid tissue. Genetic testing is available to determine an animals susceptibility. Select the least susceptible animals. “RR” breeding stock have been favored because all of their offspring will inherit a copy of the “R” (least susceptible) gene. In 2001 the USDA created National Sheep Eradication Program in efforts to eradicate scrapie in the US sheep and goat population. Through this program official USDA Scrapie tags must be in place for sheep sold, exhibited, or slaughtered. USDA Scrapie tags identify where the sheep originated by premise ID and the animal’s individual number.

SIRE (RR) R R

Q QR QR R RR RR

R RR RR R RR RR

SIRE (RR) R R

SIRE (QR) Q R

Q QQ QR R QR RR

Q QR QR Q QR QR

WHY IS IT A CONCERN - Animals are very slow growing and may never reach normal size. MANAGEMENT - Genetic testing is available to determine if the animal is a carrier of the gene. Select resistant animals.

SIRE (FF) F F

SIRE (FD) F D

F FF FF F FF FF

F FF FD F FF FD

F FF FD D FD DD

Morgan Gravatt, Freshman atModesto Junior College, CA

Genotyping Genotyping animals for any of these genetic can be done through certified labs throughout the US.