VSFCP National Standards (Revised July 2010)
National Standards Index
- 7.1 The Disease
- 7.2 Policy and Principles of Control
- 7.3 Accredited Veterinarians Responsibilities
- 7.4 Procedures Common to All Pathways
- 7.5 Pathway One Limited Acquisitions Plus Surveillance
- 7.6 Pathway Two 3rd Eyelid Screening Plus Surveillance
- 7.7 Pathway Three Genetic Selection
7.7 Pathway Three: Genetic Selection
General Information
This pathway is only available to sheep; it is not available to goats.
Advise the producer that, at the current time, this pathway to certification is not recognized by the USDA, although this situation may change in the near future.
All requirements detailed in module 7.4 Procedures Common to All Pathways are applicable to flocks participating in this pathway.
Assist Producer in Pathway Choice
The accredited veterinarian is advised to assist the producer in the decision whether or not to use genetic selection for scrapie resistance, and if so, whether to only genotype rams and pursue selective breeding for resistance, using 171RR rams exclusively; or genotype all breeding stock to access the 171RR available in both the rams and the ewes. This may be an iterative process of testing and decision making. The producer may undertake to test only breeding rams at first. With these results, it may be possible to determine whether there is a sufficient base of genetic resistance to scrapie to start a breeding program for scrapie resistance without substantial loss of other production traits, using only 171RR rams. If there is an insufficient base of genetic resistance in the ram population, the producer may undertake to test the rest of the breeding flock. These results may then be reviewed to determine if there is a sufficient base of genetic resistance across the ewes and rams to breed for resistance to scrapie without substantial loss of other production traits.
Genotype Laboratory Testing
A veterinarian accredited to deliver the VSFCP must supervise the collection of appropriate samples for genetic testing (module 7.9 Appendix 1B). The samples must be genotyped at a laboratory recognized by the CFIA for such purposes (module 7.9 Appendix 1E). Samples from 171RR rams must have the genotype confirmed by a second laboratory. (Only one of the two laboratories has to be recognized by the CFIA for genotype testing.) The cost of this verification may be minimized by requesting that the first laboratory forward only the extracted DNA to the second lab.
Whole-Flock Approach – Application
When scrapie genetic testing results document that all breeding animals are either 171RR or 171QR, the owner must submit an application for enrollment into level A of the VSFCP, with all documentation detailed in module 7.4.
Compliance with all procedures documented in module 7.4 is required upon acceptance into the program.
Scrapie Information & Facts
LABRATORIES COMPLETING OBEX
BRAIN TESTING
Prior to shipping any samples, be sure to read all information concerning packing and shipping samples.
PRAIRIE DIAGNOSTIC SERVICES
4840 WASCANA PARKWAY
REGINA, SK, CANADA, S4S 7J6
PHONE: 306-787-6435
ALBERTA AGRICULTURE
Post Mortem Room
O.S. Longman Building
6909-116 Street
Edmonton, AB Canada, T6H 4P2
Phone: 780-422-1923
ANIMAL HEALTH LABRATORY
Laboratory Services, a division of
the University of Guelph
Building 49, OVC, Box 3612,
Guelph, ON, Canada, N1H 6R8
Phone: 519-824-4120 X: 54544
Fax: 519-821-8072
- Click here for more details
- *This lab is CFIA approved
Whole-Flock Approach – Acquisitions
Natural increases (home-grown replacements): Lambs born from a mating involving at least one 171RR parent may be kept and used as breeding stock without requiring a genotype test.
Natural increases (home-grown replacements): Lambs born from a mating not involving at least one 171RR parent must be genotyped if retained as breeding stock. Only 171RR or 171QR animals may be retained as breeding stock. Animals from non-RR matings that are not genotyped must be removed from the flock by 12 months of age. If one of these animals is accidentally bred with lambs on the premises, the flock status will be suspended, pending investigation.
Acquired replacement breeding stock (purchases/loans): Newly acquired breeding stock must be genotyped as 171RR or 171QR by a laboratory recognized by the CFIA for that purpose (module 7.9 Appendix 1E). Semen must be sourced from a ram genotyped as 171RR or 171QR by a laboratory recognized by the CFIA for that purpose (module 7.9 Appendix 1E).
Whole-Flock Approach – Advancement
After 12 months at level A, the producer may apply to advance to the certified level. Once a flock has reached the certified level, it maintains this level, provided that the applicable requirements continue to be met.
Rams-Only Approach – Pre-Application
Following the producer’s decision to pursue the rams-only approach to selection for genetic resistance to scrapie, it will probably take a number of years of ram testing, selection, breeding, and culling to assemble an entire flock that can be documented to be offspring from resistant rams. Through this period, the accredited veterinarian’s role will be limited to sampling of the rams for genotyping.
Once the producer can document through breeding records that all remaining animals are offspring of a ram genotyped 171RR, the owner must submit an application for enrollment into level A of the VSFCP, with all of the documentation detailed in module 7.4.
Compliance with all procedures documented in module 7.4 is required upon acceptance into the program.
Rams-Only Approach – Acquisitions
Acquired replacement breeding stock (purchases/loans): Newly acquired breeding rams must be genotyped as 171RR by a laboratory recognized by the CFIA for that purpose (module 7.9 Appendix 1E). Semen must be sourced from a ram genotyped as 171RR by a laboratory recognized by the CFIA for that purpose (module 7.9 Appendix 1E). Purchased breeding ewes or embryos must be genotyped as 171RR or 171QR by a laboratory recognized by the CFIA for that purpose (module 7.9 Appendix 1E).
Rams-Only Approach – Advancement
After 12 months at level A, the producer may apply to advance to the certified level. Once a flock has reached the certified level, it maintains this level, provided that the applicable requirements continue to be met.
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