Serologische Untersuchungen von Sauenmilch und Ferkelblut als mögliche Alternative zur Blutuntersuchung von Muttersauen im Rahmen der Bestandsdiagnostik

The aim of this study was to find a reliable alternative to the
usually employed method of serological blood examination of sows,
since taking blood samples from pigs, especially from sows, is very
difficult and causes considerable stress for the animals. From July
2002 until May 2003 milk and blood samples from 180 sows and three
piglets per litter were taken in a livestock of 128 sows and about
1000 fattening pigs. All samples were tested by ELISA for
antibodies against eight important infectious diseases in pig herds
(Aujeszky's Disease (AD), Swineinfluenza (SI), Mycoplasma
hyopneumoniae Infection (EP), Porcine Parvovirus Infection (PPV),
Porcine Reproductive and Respiratory Syndrome (PRRS), Transmissible
Gastroenteritis (TGE), Porcine Respiratory Coronavirus Infection
(PRCV) and Sarcoptes suis mange). All dams were vaccinated
regularly against Influenza and PPV and were treated for mange
before being moved into the farrowing unit. In the first week of
life all piglets were vaccinated against EP. Milk samples were
taken on the 1st, 2nd, 3rd and 7th day p.p. (post partum). Blood
samples of the sow and the piglets were taken on the 4th day p.p.
All samples were analysed by commercial ELISA-testkits, though only
Hyoptest II and Sarcoptest are commercially used for serological
milk testing. The results of the sows' blood testing served as the
basis for the evaluation of the colostrum, milk and piglets' blood
samples. Sensitivity, specifity, positive and negative predictive
factor were determined. Further more the development of the milk
antibody concentration p.p. and a comparison of sows' and piglets'
antibody titers was demonstrated. The results for the
seroprevalence of the blood tested sows are as follows: AD 0 %, SI
93 %, EP 46 %, PPV 77 %, PRRS 0,7 %, TGE 4 %, PRCV 65 % and mange 4
%. The following results were established: I. Aujeszky's Disease:
The suitability for ELISA testing is questionable because of
lacking seroprevalence. The piglets' blood testing is a suitable
alternative to sows' blood testing. II. Influenza: The milk
antibody titer is constant from the 1st until the 7th day p.p.
Colostrum does not seem to be as suitable as milk from the 2nd day
p.p. onwards. The serological piglets' blood testing is a very
reliable alternative. III. M. hyopneumoniae: From the 3rd day p.p.
onwards the antibody titer falls below the cut off limit. Colostrum
may be a suitable alternative, whereas the use of milk taken from
the 2nd day p.p. is limited. Milk from the 3rd day p.p. onwards
cannot be used as a replacement for blood testing. Piglets' blood
testing seems to be suitable. It has to be mentioned that there are
some false positive results in both milk and piglets' blood test
results. IV. PPV: The antibody titer is constant throughout the
whole period. Both colostrum and milk samples as well as piglets'
blood can be used for antibody detection instead of sows' blood. V.
PRRS: Both colostrum and milk as well as piglet's blood can serve
as an alternative for sows' blood testing. VI. TGE: The serological
colostrum and milk examination cannot be used for detecting
antibodies against TGE virus, whereas piglets' blood testing can be
used as an alternative. VII. PRCV: The milk antibody titer is
constant from the 1st until the 7th day p.p. The use of milk and
colostrum as an alternative for sows' blood testing is
questionable. Piglets' serological examination seems to be
suitable. VIII. Mange: Even though colostrum testing is already
used in mange herd surveillance in Switzerland, according to this
study, the suitability of colostrum is questionable. Milk from the
2nd day p.p. onwards cannot be used for detecting antibodies
against Sarcoptes suis. Further more the serological blood testing
of piglets is questionable, because of the high number of false
positive results.