National Scrapie ID Program is the Basis of the Sheep Industry?s Plan for the NAIS
By Amy Conner
'Scrapie' is a familiar word for most U.S. sheep producers. Introduced to the United States in 1947, scrapie costs U.S. sheep producers today an estimated $20 million to $25 million annually, primarily due to increased disposal costs and lost revenue through the loss of markets for inedible byproducts.
The U.S. Department of Agriculture (USDA) implemented programs to identify scrapie and eradicate it in 1952. Four decades later in 1992, USDA's Animal and Plant Health Inspection Service (APHIS) and producers, allied industry representatives, accredited veterinarians and state animal health officials changed their approach and began the voluntary Scrapie Flock Certification Program (SFCP). It focuses on monitoring flocks and identifying those that are scrapie-free - a certification that allows producers to enhance their flocks' marketability. A flock is considered free of disease as long as no sheep originating from or residing within the flock is diagnosed with scrapie. After five years of monitoring, flocks are considered free of the disease.
In 2001, the approach to scrapie became two-fold: flock certification and disease eradication. In addition to the SFCP, APHIS developed the accelerated National Scrapie Eradication Program (NSEP).
The NSEP focuses on the following actions: (1) detecting pre-clinical sheep (infected sheep showing no clinical signs of scrapie) through slaughter surveillance, necropsy or live-animal testing of high-risk animals, and live-animal surveillance testing in flocks that are believed to be at higher risk due to management practices and flock composition; (2) tracing infected animals to their flock of origin; (3) supporting genetics-based, clean-up strategies that allow producers to stay in business; (4) tracing and testing exposed animals that have been sold out of infected flocks; and (5) monitoring for and requiring compliance with the identification and recordkeeping requirements that make it possible to trace animals.
To determine the prevalence of scrapie in the U.S. sheep flock, APHIS collected data through the Scrapie Ovine Slaughter Surveillance (SOSS) study from April 1, 2002, through April 2003. According to the 2004 APHIS Scrapie Program Factsheet, the disease occurred in an estimated 0.2 percent of mature sheep in the United States.
However, animal health officials are not just limited to slaughter surveillance for diagnosing this disease. The third eyelid test to detect scrapie in live animals was approved by APHIS in 2001. Until the approval of the third eyelid test, there was no way to diagnose scrapie in live animals without the use of general anesthesia.
"The impact of the live-animal test is significant because it allows APHIS to conduct testing in exposed flocks to determine if they are infected," says Diane Sutton, DVM, national scrapie program coordinator at the USDA/APHIS, Veterinary Services, National Center for Animal Health Programs.
The Regulatory Scrapie Slaughter Surveillance (RSSS) program began after the conclusion of the SOSS in 2003. The RSSS is utilized to identify as many scrapie-positive sheep as possible. The positive animals are traced back to any flocks in which they may have lambed, and to the flock in which they were born, so that regulatory officials may assist in cleaning-up these flocks. Since the beginning of this program, May 2003 through February 2005, samples from 42,095 sheep have been collected in slaughter facilities around the country. Of the samples collected, 120 were positive for scrapie.
Tracing infected sheep and eradicating disease are much easier to accomplish when the animals involved are identified and their movements can be tracked. In August 2001, USDA published regulations requiring U.S. sheep producers to acquire a scrapie premises identification number in order to acquire official eartags and, in most cases, to identify their sheep with APHIS-approved identification tags or other official identification.
Working with industry and the States, USDA published a program standards document, also called a Uniform Methods and Rules (UM&R) document, to supplement these regulations.
"The UM&R provides guidance to state and federal personnel on program implementation to maintain consistency between the States," says Sutton.
The UM&R has been revised to reflect technical advances and uniformity issues, since the NSEP was implemented and is reviewed at least annually.
Sheep Working Group Looks at Animal Identification
By 2003, sheep producers were not just concerned about animal and premises identification required under the scrapie program. That year, an overarching U.S. Animal Identification Plan (USAIP) was developed, affecting all livestock producers. To ensure that the concerns of the sheep industry were addressed in the USAIP, a sheep-specific working group was developed. The group was comprised of various stakeholder groups, such as breed association representatives, packers, feeders, range and farm flock producers and veterinarians.
The working group recommended a sheep identification strategy in 2004 to the USAIP steering committee. The strategy would use the existing national scrapie ID plan as a starting point for the sheep industry. This ID system was more complete than those that existed for other species in the United States.
"Because of the scrapie ID program, the sheep industry is ahead of the rest when it comes to implementing a mandatory animal identification system," says Paul Rodgers, deputy director of policy at ASI.
The other major points emphasized by the sheep working group were:
Instead of creating a sheep identification plan from scratch, the sheep industry wanted the USAIP to build from the scrapie ID plan. They hoped that scrapie premises identification numbers could be transferred to the animal ID program, although the industry did realize one drawback of the scrapie ID program ? it is a manual, visual system.
Based on the recommendations from the USAIP working groups and other interested stakeholders, the framework for the National Animal Identification System (NAIS) was developed by the USDA in 2004. The NAIS is an identification and tracking system that, when fully implemented, will provide for rapid tracing of infected and exposed animals during an outbreak situation. The goal is to be able to trace these animals within 48 hours of a presumptive positive diagnosis, to identify the scope of the outbreak and to ensure that the disease is contained and eliminated.
How NSEP Fits With the NAIS
"The National Animal ID System will support NSEP since the scrapie program is an eradication program with an ID requirement, and the NAIS is an identification and animal tracking system," says Sutton. "Eventually NAIS identification methods will replace the current ID component of NSEP. However, until NAIS is implemented, NSEP will continue to provide ID and tracking for the scrapie program."
"As this program is being created, it is important for producers to be aware that each species working group is developing its own guidelines," says Rodgers. "Producers may hear what is being developed for the cattle or swine industries, but those guidelines may not be necessarily relevant to sheep."
The recommendations are now being formatted into a guidelines document, or program standards, to be submitted to the USDA. This document is based entirely on the sheep working group report that is available at www.sheepusa.org. It elaborates on many of the NAIS issues affecting the U.S. sheep industry.
One main issue is that NAIS does recognize the significance of group identification for sheep. Group, rather than individual numbers, may be assigned to certain groups of sheep. For example, single source lambs moving as a group through the slaughter channels.
Secondly, the guidelines recognize diseases that are important to the U.S. sheep industry, such as scrapie and foot-and-mouth disease (FMD), and how their spread could be impacted by the identification and tracking components of the plan. Due to the long incubation period of scrapie, identifying breeding ewe lambs and ram lambs prior to their leaving their birth flocks, and tracking ewes throughout their reproductive lives, would be sufficient for tracking this disease. However, FMD has a very short incubation period, two to 14 days, and requires different tracking methods. Specifically, to control FMD and other highly contagious diseases, an infected or exposed animal would need identification that ties it to movements made during the preceding three to four weeks, not just to its premises of birth. For instance, the records for a group of finished lambs would identify date of movement, the exact number of lambs in the group, the farm/ranch they left and any unloading points along the way to slaughter.
A third issue the report defines is which animals need to be identified, and which animal movements should be tracked. For example, identification and tracking would be required when sheep moving to exhibitions or animals are being sold as: (1) breeding stock or (2) feeder lambs or sheep moving to exhibitions, regardless of whether these movements occur within a state or across state lines. Ideally, the focus would be to identify sheep that have the opportunity to commingle with another producer?s sheep.
Fourthly, the report defines what is effective and affordable for producers in terms of ID devices, and also suggests using the same distribution system as is currently used by the NSEP.
And finally, the group has developed a budget, which includes a government/industry cost-sharing plan.
Challenges in Making Electronic ID Work
"There are challenges in making electronic ID devices that work routinely at the everyday farm-level in sheep," says Cindy Wolf, DVM, assistant clinical specialist with the University of Minnesota, vice-chair of the ASI Animal Health Committee and chair of the Sheep ID Working Group. "However, members of the Sheep ID Working Group are researching and studying countries with larger sheep populations than the United States, who are investing heavily in testing on-farm application of electronic ID of sheep."
Some of the challenges these other countries are experiencing include: reader failures; difficulty in setting up readers in a farm setting due to problems such as interference with metal, cords and batteries; lack of robustness of equipment; and lack of user-friendliness on the part of some readers.
"While the sheep industry acknowledges the potential value of an electronic data-tracking system, leaders are of the opinion that the technology is not yet ready for widespread on-farm application," Wolf says.
Wolf fully expects, ":The USDA to continue to increase its enforcement of the current scrapie identification requirements."
Recently a few dealers were fined by USDA for moving cull ewes without identification.
She stresses the importance of applying official scrapie tags to all animals that are over 18 months of age (cull ewes and rams) in commerce; all breeding stock that change ownership, regardless of whether they go across state lines; all animals traveling to exhibitions; and all ewe lambs not in direct slaughter channels.
Until NAIS becomes mandatory, producers are urged to contact their state veterinarian, register for NAIS, and request that their scrapie premises identification number, also known as the scrapie flock ID, be associated or linked in the database with their NAIS premises number.
Sutton also suggests, "Next time a producer requests their NSEP tags, they should also provide their NAIS number to the clerk who answers the 866-USDA-TAG number, so that it can be associated with their scrapie flock ID."
Eventually, the voluntary NAIS will become a mandatory program for all livestock species and the NAIS premises identification number (PIN) may replace the scrapie premises number in the Scrapie National Generic Database. It is projected that by the end of this summer, companies producing USDA-approved scrapie tags that are NAIS compliant will become NAIS animal identification number managers.
This is the reason why it is important for producers to register with the scrapie program and NAIS. It will only be through the direct involvement of producers, that the spread of scrapie and other animal diseases can be prevented. To register with the scrapie program and obtain official eartags call, 1-800-USDA-TAG. To register with NAIS, call your state veterinarian?s office.
Scrapie and the National Animal Identification System (NAIS) Timeline
1947 - Scrapie was first found in the United States
1952 - Scrapie eradication program initiated
1990 - APHIS established the Scrapie Negotiated Rulemaking Advisory Committee
1992 (October) - APHIS Implemented the Voluntary Scrapie Flock Certification Program (VSFCP) and moved from an eradication to a control program
1997 (October) - The VSFCP was modified to make it more useful to commercial producers
1999 - APHIS reviewed and revised the VSFCP
1999 (July) - The revised Scrapie Flock Certification Program (SFCP) became effective
2001 (April) - The Scrapie Ovine Slaughter Surveillance Study (SOSS) methods development, phase I, began
2001 (August) - Federal regulations put the accelerated National Scrapie Eradication Program (NSEP) into effect
2001 (September) - APHIS makes official eartags available free to producers, dealers, and markets
2001 (October) - APHIS approves the third eyelid test for the diagnosis of scrapie in live sheep
2002 (April) - The Scrapie Ovine Slaughter Surveillance Study (SOSS) prevalence determination, phase II, began
2002 (April) - The National Food Animal Identification Task Force of more than 30 livestock organizations announced to develop the National Identification Work Plan (NIWP)
2002 (November) - APHIS adopts genetics based flock cleanup plans as the standard method for cleaning up scrapie-infected flocks
2003 (January) - The National Identification Development Team (NIDT) Steering Committee created
2003 - USDA received $15 million in appropriated funding to conduct the NSEP
2003 (October) - The Scrapie Eradication Uniform Methods and Rules were published
2003 (April) - The SOSS study concluded and Regulatory Scrapie Slaughter Surveillance (RSSS) began
2003 (July) - The NIDT created the U.S. Animal Identification Plan (USAIP)
2003 (December) - APHIS approves immunohistochemistry on lymphoid tissue as an official test for scrapie
2004 (January) SOSS study results published, results can be found on the National Animal Health Monitoring System Web site at http://www.aphis.usda.gov/vs/ceah/ncahs/nahms/index.htmand clicking the on the sheep link
2004 (April) - Sheep specific animal identification plan was presented to the NIDT Steering Committee
2004 (April) - The USDA adopted the USAIP and developed the National Animal Identification System (NAIS)
2004 (September) - APHIS entered into a cooperative agreement with the University of Minnesota to review sheep and goat ID methods for use in the integration of NSEP with NAIS
2005 (March) - APHIS issued first permit for an ELISA test for scrapie
2010 - The goal is to eliminate outbreaks of scrapie in the United States
2017 - The goal is for the United States to be declared scrapie-free by the Office International des Epizooties (OIE)