By Colleen Schreiber
SAN ANGELO — The scrapie eradication program officially got underway in November 2001. In Texas, full compliance with the regulations is set to be enforced beginning April 1.
Diane Sutton, DVM, senior staff veterinarian and national scrapie program coordinator with USDA's Animal and Plant Inspection Service, conducted an informational meeting here last week for Texas sheep and goat producers. She also spoke at the recent Mohair Council of America annual membership meeting.
Scrapie, a fatal degenerative disease affecting the central nervous system of sheep and goats, was accidentally introduced into the U.S. in 1947. It is a "transmissible spongiform encephalopathy," in the same category as so-called "mad cow" disease. There is no evidence that scrapie can spread to humans, either through consumption of meat or dairy products or through handling of animals, but the sheep industry has been subject to negative publicity because of public perceptions.
The American Sheep Industry Association estimates that scrapie costs the industry somewhere between $20 million and $25 million annually. Scrapie negatively impacts U.S. producers' ability to export live animals, semen and embryos throughout the world. Some countries, particularly Japan, one of the major consumers of U.S. meat byproducts and bone meal, has voiced concern that the U.S. still has scrapie. Many renderers also are declining to pick up sheep offal and carcasses from mature animals.
It is primarily for these reasons that the industry is pulling out all the stops to finally eradicate this insidious disease. It is APHIS' intention to eliminate the clinical disease by 2010 and to seek official recognition from the international community by 2017, Sutton said. A country must be free of the disease for seven years before it can be recognized officially "free" internationally.
APHIS has approved the "third eyelid" test for diagnosis of scrapie in sheep but not in goats.
"In the past, when an animal was known to have been moved out of an infected flock, all we could really do was inform the owner that they had animals potentially at risk and recommend that they be euthanized," Sutton told listeners. "Now we can test those animals and determine their status, which will help us move forward quickly and confine the infection."
In 2001 there were 98 confirmed scrapie cases in the U.S. The number of infected flocks has risen over the last year or so, simply because of the stepped up efforts brought on by the eradication program. As of September 30, 2001, there were 67 known scrapie-infected and source flocks.
In goats, scrapie is a relatively rare event. Since 1990 there have only been seven reported cases.
More than 900 sheep flocks currently participate in the voluntary certification program. It takes five years of monitoring to ensure that a flock is free of the disease. Today 66 flocks are certified free.
Scrapie, Sutton noted, is a contagious disease caused by an infectious agent. It is not a genetic disease, though the susceptibility of an animal is influenced by its genotype. Up to 30 percent of the animals can be infected in flocks that have highly susceptible genetics.
Different genotypes influence whether or not a sheep will develop clinical scrapie. The strains of scrapie known in the U.S. are expressed at codon 171, with QQ animals being most susceptible and RR animals most resistant. It is not known whether genetic resistance occurs in goats, Sutton said.
One of the first clinical signs of scrapie is a change in behavior of the animal, followed by scratching and rubbing, though some animals may never exhibit that behavior. Other clinical signs include loss of coordination, lip smacking, weakness, heat tilt, muscle tremors and weight loss. Some animals are simply found dead. Animals that exhibit clinical signs of scrapie never recover.
Neonatal (at or near birth) animals, Sutton said, are most susceptible to scrapie. Animals that are exposed to scrapie after they are weaned are much less likely to come down with the disease. Incubation time for animals that are exposed at or near birth is two to five years. However, incubation in animals exposed later in life can stretch as far as 12 years.
Only the placenta and birth fluids are known to contain infectious material. The infectious agent is extremely difficult to destroy. It must be incinerated or treated with high levels of bleach or lye or buried deep in the soil.
Rams are believed to be very low risk for spreading scrapie, and artificial insemination does not transmit the disease.
In 2001 the federal government utilized $2.9 million in appropriated funds and another $2.11 million in emergency funds to kick-start the eradication program. Another $2.9 million has been appropriated for FY 2002, along with an additional $2.76 million in emergency funding. For FY 2003, APHIS is requesting $19 million.
To speed up the eradication process, the agency is offering incentives for owners of infected flocks to report their status by guaranteeing indemnity funds. The government is also paying for the cost of the third eyelid test in infected flocks and will assist in genotyping.
To comply with the regulations, producers must first determine if they own animals which must be identified in order to be sold or move in interstate commerce. The following are some basic rules which apply prior to sale of the animal as outlined by Sutton:
Breeding ewes and rams that are going to a show need official ID, Sutton said, because a show is considered interstate commerce if out of state animals are attending the event.
Fat lambs under 18 months of age going to slaughter do not require official identification. However, ewe lambs under 18 months of age may not leave slaughter channels unless they have official ID. In other words, if there is a chance that the ewe lambs will be sold for breeding replacement, they need official tags.
Non-positive, non-exposed, non-high-risk and non-suspect culled goats going to slaughter do not require official ID. Conversely, culled sheep over 18 months of age going to slaughter do need official ID.
Once a producer has determined whether animals need official identification, they must contact their state veterinary services to request a premise ID number and to order tags for their animals. In Texas, the contact agency is the Texas Animal Health Commission. To request a premise ID number and to order tags producers should call (866) 873-2824. The free tags come in white plastic or white metal and will be shipped direct to the individual in eight to 10 weeks. The tags will have a premise number and an individual animal ID embossed on the tag.
"We plan to have free tags available forever," Sutton said. "We recommend that producers order enough tags to get them through a few years."
Recordkeeping is a critical part of the eradication program, Sutton told producers. Flock of origin owners who apply tags need to record the date the animals were tagged and the number of animals tagged. If the animals were born after January 1, 2002 in another flock and were not already identified as to flock of origin, they must also record the name, address and phone number of the owner of the flock at birth.
Any kind of recordkeeping forms may be used, but forms are also available through the APHIS office.
When an animal is sold, the owner must provide the buyer with flock of origin information, Sutton said. The owner must also keep records for a period of five years after the animal is sold or dies. Records must indicate the number of animals sold and the premise ID number. The owner must also record date of sale and the name, address and phone number of the buyer. If the animals are identified with ear notches or official brand, records should include a copy of the brand inspection certificate.
The recordkeeping process is basically the same for the buyer.
Health certificates are also required when an animal is moving interstate or when it is participating in an interstate show.
The owner, Sutton said, is the primary person responsible for making sure that proper identification is applied before animals are moved in interstate commerce. However, anyone who handles unidentified animals in interstate commerce can be held legally responsible.
There is not a regulation on the books yet for intrastate movement in Texas. However, regulations will be drafted and presented to TAHC in February. It is expected that those regulations will mirror USDA premise identification requirements.
Scrapie positive and suspect animals may not be moved under any condition other than for research or destruction, Sutton stressed.
The government is also instituting a slaughter surveillance program that will help detect scrapie incidences.
"I can’t eradicate scrapie sitting at my desk in Washington," Sutton concluded. "Scrapie can only be eradicated if all ranchers decide they want this program to succeed. I need your help, your cooperation and your input."
Following her formal presentation, producers directed specific questions to the program coordinator. A sample of them follows.
When is the last day I can sell an animal in Texas without a tag?
"April 1. Tags take six to eight weeks for delivery. Metal tags take a little longer. If you have ordered tags, and they’re not here and you have some animals that you want to sell, if it’s before April 1 then you can sell them without tags."
If I'm raising commercial goats that are not commingled with sheep, do these goats have to be tagged in order to move in interstate commerce?
"No. If you're raising low-risk commercial goats, I probably would not buy an animal that has been commingled with sheep unless it comes from a flock that you’re very familiar with."
What about registered goats from the same herd running under the same conditions?
"If they are being shown or sold as registered animals they need to be moved with their registration papers or the health certificate listing that information. Because registered animals are required to have an identification by the registry association, we didn’t feel that another tag was necessary.
"However, if these goats are moving to a livestock market, they need a premise tattoo or a tag."
What is the definition of low risk commercial sheep?
"Low risk commercial sheep may be moved in interstate commerce utilizing a registered brand or ear notch pattern if they’re accompanied by a brand inspection certificate."
If one is participating in the voluntary scrapie flock certification program, are there restrictions on adding additional animals to the herd?
"If a producer is participating in the program and becomes certified free, then that producer may only purchase rams or ewes from other certified flocks or from any enrolled flock if that animal is born in that flock or resided in that flock for one year. Purchasing animals from any other flock would cause that producer to lose his certified free status for a period of one year.
"We are considering a change so that rams kept independent of the flock and not commingled during lambing can be used."
What kind of regulations are there on semen?
"All semen except from infected or high risk animals may be used for breeding purposes."
How soon after incubation is the "third eyelid" test a valid test for identifying scrapie?
"For sheep, if the animal is exposed at or near birth, which is the case for most animals, it can be detected in most animals at 14 months of age."
Is there an ongoing effort to develop a similar test for goats?
"We haven’t had enough positive goats to get a correlation on the accurateness of the test for goats."
What is the definition of commingling of sheep and goats?
"Commingling means that the animals are running together in the same pasture or in the same pen.
"We are considering a possible amendment which will allow commingling of sheep and goats except during lambing and 60 to 90 days after lambing."
I am a commercial sheep breeder and I sell my ewe lambs through a livestock market. I assume that those ewe lambs are going to a feeder and then on to slaughter, but I never know for sure. Sometimes they're sorted out, and they go back to the country as replacements. Am I liable if those animals are not tagged?
"In this case if the auctioneer announces the sale as slaughter animals, then your liability is limited at that point.
"If the sale was announced as a slaughter sale and the buyer of those ewe lambs sorts them out with the intention of using them as replacements and they're not tagged, then he is in violation and could be fined.
"The same applies to slaughter goats. If the sale is announced as a slaughter sale and your goats are low risk and not tagged, then the auction facility is covered, the owner is covered, and the buyer who buys these animals other than for slaughter is the one in violation for picking up breeding animals that were not tagged."
If I buy a set of lambs that were sold as slaughter lambs and I decide to keep them, can I put my own tags in those ewe lambs?
"If you have that thought in your mind, then the best thing to do is buy lambs that have tags. However, if you can identify the flock in which those animals were born, then you may tag them with your own tags. You must keep up with the flock of origin information."
Why don’t you just require that all females regardless of age be tagged?
"We originally proposed that and everyone told me that they couldn’t possibly do that, that it would destroy the sheep industry.
"The only ewe that doesn’t have to be tagged is a slaughter ewe lamb. All other ewes have to be tagged whether or not they’re going to slaughter or back to the country. If they’re not tagged and they come to the auction, then the auction operator will have to tag them and the owner of those lambs will be charged a fee."
If a ewe leaves the state and lambs while on another premise but the ownership does not change, am I required to tag the animal?
"You are not technically required to tag the animal if
ownership did not change. However, if it was commingled with other
sheep during lambing, it would be advisable to at least keep a record
of the flock of origin of the other ewes."
"We ask that you keep the original tag and apply your own tag as well if those animals are ever sold."
What happens when an animal loses its tag?
"If those animals were all born and bred on your place, simply put a new tag in. If they were not born and bred on your place, then we ask that you keep records of lost tags to the best of your ability."
If this is not really a whiteface sheep problem, why must they fall under the same regulations?
"The problem is that we’ve waited too long to deal with the issue in the blackface animals, and now it is a whiteface problem. We've been lucky so far in that it appears to have not gotten into our larger range flocks. The problem is when these animals go to market, it’s not easy to tell the difference between a large range flock ewe and a backyard operation ewe. We’ve had quite a few positives in whiteface farm flocks."
Why must rams be identified?
"We don't exempt ram sheep from identification even though they’re not carriers, and we don’t exempt them because they are an excellent traceback tool for finding an infected flock."
How long does the prion remain viable?
"Hamster scrapie is the most infectious. In one study, an infected hamster was buried in a flowerpot and dug up three years later and it was still infectious enough to spread the disease. That wasn't a real life situation, but the point is that this is not a fragile organism."
You talked about cleaning an infected area. How do you
disinfect a three or four-section pasture?
"Typically, operations that lamb on the open range will not have a problem because the infectious material will be diluted down. Animals that have a greater chance of receiving an effective dose are those that are lambed in confinement. In that situation, the area needs to be scraped clean, either down to the cement or bare soil."
If a producer has to depopulate a herd, can he buy back in and run sheep or goats on the same premise?
"Yes, but those animals will have to undergo a five year monitoring plan. And if the producer comes back with low risk commercial goats, those goats in that situation would also have to be identified with tags when sold."
What about animals going to Mexico?
"If an animal is over 18 months of age and it's going to Mexico, it must have a tag."
Is there a plan in the works for identifying individual states as scrapie-free?
"There is plan on the table for how to declare a state or region free of scrapie. We welcome comments on the draft. Probably the best way to handle it is to have scrapie-free regions. If Texas were declared scrapie-free, to maintain that status, producers wouldn’t be able to bring in any animal that wasn’t from a scrapie-free flock unless it was going to slaughter. We need to be able to maintain a similar status with our trading partners like our neighboring states.
If I am purchasing outside animals for breeding purposes, how can I be sure that the herd is not infected with scrapie?
"Under the current new rule, only infected or source flocks who refuse to cooperate are listed on the APHIS website. However, anyone who owns a source flock is required to reveal that information prior to the animals being sold. If they don’t, they're in violation."
What are packinghouse requirements?
"A packing plant may only accept slaughter ewes if they are tagged. If the plant is participating in the slaughter surveillance program, they must collect all ID when the collector is there. If the slaughter plant is not participating in the surveillance program, they must collect all ID at all times.
"At present, goats going to slaughter do not have to be tagged because we are not sampling them at the slaughter facilities. At some point we will have to be able to do a representative sampling so that we can demonstrate to the world that we are scrapie-free. We intend to hold off on this for awhile, at least until we get the disease in sheep on the run."
William Edmiston, DVM, and chairmen of the health and product development committee for Texas Sheep and Goat Raisers Assocation, said the scrapie program is a lot like taking medicine.
"It costs money, and a little time, and reading the package insert will scare the pants off you because of all the risks involved, but when you take the risks versus benefits, in perspective, it's not that big a deal."
To view a chart relating to above article go to www.animalagriculture.org/scrapie
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