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Porcine Stress Syndrome
(PSS): The HAL-1843* DNA Test
- Why
should you be concerned about PSS?
- What is
PSS?
- DNA
PSS test using PCR
- Who
is VITA-TECH Canada Inc.?
Why
should you be concerned about PSS?
The mutated gene responsible for
Porcine Stress Syndrome (PSS) has been maintained in some breeding
stocks for the slight benefits it yields over normal pigs. These
benefits include leaner and bulkier pigs and an increase in
development. Some believe that the increase in lean meat content
is approximately 1 to 2 % for heterozygous carriers and 4 to 5 %
for homozygotes.
On the other hand, the PSS gene
also has negative effects which can lead to premature death or
more commonly Pale, Soft Exudative (PSE) pork. PSE pork begins to
lose its water content shortly after slaughter and its appearance
and smell are not appealing to the consumer. In fact, one half of
poor quality pork is attributed to the PSS gene. In addition to
these obvious sources of economic loss, sows which have the PSS
gene have reduced reproductive performance.
Many large breeders have opted to
develop new PSS-free breeds which offer improved leanness and
muscle bulk without the ill-effects or economic loss caused by
PSS. When all things are considered, one comes to realize that it
is in one's best interest to eliminate or at least control the PSS
gene in their breeding stocks.
What
is PSS?
PSS is a hereditary disorder in
swine of all ages. Pigs affected with this disorder display the
following characteristics when subjected to stress:
- dyspnea (rapid heavy breathing)
- premature death
- muscle rigidity
- hyperthermia
PSS is caused by a mutation in the
halothane gene. It was called the halothane gene because PSS
positive pigs exposed to halothane gas show typical PSS symptoms.
Since all animals carry two copies of every gene, the status of
the halothane gene can be classified by one of three designations:
- "nm" (normal
or negative) - This indicates that both copies of the
PSS gene are normal and the pig is negative for PSS.
- "mm"
(heterozygous or carrier) - This indicates that one
copy of the PSS gene is normal and the other is mutated. These
pigs are often called carriers because they do not always show
typical PSS symptoms but can still pass on the mutant PSS
gene.
- "dm"
(homozygous or positive) - This indicates that both
copies of the PSS gene are mutated and the pig is referred to
as being positive for PSS.
DNA
PSS test using PCR
With the older Halothane test, only
pigs that are homozygous for the PSS mutation can be screened out
of a herd population. It does not identify those pigs that are
heterozygous carriers of the gene. The recently developed PSS DNA
polymerase chain reaction (PCR) test, called the HAL-1843* DNA
test, not only detects homozygous pigs, but also those that are
heterozygous carriers. This gives swine breeders complete control
over the PSS gene in their herd.
The HAL-1843* test is a cutting
edge DNA-based test capable of processing a large number of
samples per day. Additional advantages of the HAL-1843* test
include:
- quick turn around time
- highly accurate results
- various sample collection
methods accepted
-
- venipuncture collection in
purple- or green-top Vacutainer tubes
- lancet prick with filter
paper collection
- lancet prick with swab
collection
- muscle, fat, lung and liver
tissue for post-mortem
Filter paper cards and
requisition forms are supplied free of charge.
Who
is VITA-TECH Canada Inc.?
VITA-TECH Canada Inc. is Canada's
largest privately owned veterinary diagnostic laboratory, located
in Markham, Ontario. We have long been recognized for:
- industry leading commitment to
providing outstanding service
- voluntarily following strict
Quality Assurance/Quality Control programs
- our laboratory which boasts some
of the most advanced instrumentation available in veterinary
medicine
- one of the first veterinary
laboratories to be completely computerized from specimen
receipt right through to result reporting
- our active involvement in the
research and development of new and improved diagnostic tests
ad services
VITA-TECH Canada Inc. has been
licensed by Innovations foundation of the University of Toronto to
provide HAL-1843* DNA testing to screen for PSS. For each sample
tested, confirmed results are faxed to you automatically by our
computers, or phoned to you by our reporting staff. Also, a
certificate is issued indicating the animal's ID and the
corresponding HAL-1843* designation. In addition to our PSS
testing service, we also perform ELISA-based Porcine
Respiratory and Reproductive Syndrome (PRRS) virus and Pseudorabies
virus tests using whole blood samples collected in 'red'-top
Vacutainer tubes.
In keeping with our commitment to
providing the PSS test at a highly competitive fee, we are
currently in the process of setting up PRRS virus and Pseudorabies
virus tests which would utilize the same dried blood sample
submitted for PSS testing. This would save the pig owner/breeder
time and money and give them greater control over their herd.
We are proud to offer this quality
service and look forward to your patronage. Our friendly, helpful
staff is available to answer any questions you may have from early
morning to late evening, six days a week. For inquiries regarding
PSS, PRRS and Pseudorabies testing, or any of our other services,
please do not hesitate to contact us.
* HAL-1843 is a licenced registered
trademark of Innovations Foundation of the University of Toronto.
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