One of the main components of any control or clean-up
plan is a thorough and strict biosecurity procedure to con
tain and prevent the spread of disease. Pseudorabies (PR)
clean-up can be frustrating or unsuccessful if biosecurity
issues are not addressed.
First, we must consider that the primary source of PR
virus is probably the pig itself, and is spread either by direct
contact or aerosol. All pig movements must be done in a way
that minimizes the chance of disease spread between ani
mals. Spreading between animals occurs when pigs of dif
ferent age groups have close contact. Cull sows should never
be kept in the finishing barn. Pig movements should be
planned as all-in/all-out when possible.
The disease threat to younger animals of keeping tail
enders around is usually greater than losses from moving
them out promptly. Additional walls or partitions may be
necessary to gain greater separation between groups of ani
mals. Air supply needs to be sourced from the outside, not
from another group of hogs.
When tending pigs, work from the youngest to the oldest
with frequent use of disinfecting foot pans, especially in the
finishing barns. When they get dirty, foot pans quickly
become ineffective at killing disease organisms, so replace
the disinfectant solution often. It is recommended to change
coveralls and/or boots between the breeding and grow/finish
herds.
Equipment that is needed in several places on the farm
should not be shared. Separate snares, syringes, or hog
On-Farm Biosecurity For Swine
panels should be kept for each phase of the operation. If this
is not possible, equipment should be thoroughly washed and
disinfected between groups of animals to prevent disease
transmission.
Common disinfectants are: formaldehyde-based
(DC+R®), phenol-based (One Stroke Environ®, Magna
phen®, Biophene®, Tek-Trol®, others), quaternary ammoni
ums (Roccal-D®, Zephiran®), tamed iodine (Betadine®,
others), and lye. There are differences between disinfectants
in toxicity, corrosiveness, and effectiveness in the presence
of dirt and low temperatures.
DC+R is not effective at temperatures below 60 degrees
and can be dangerous to use if ventilation is inadequate. Lye
and phenol-based disinfectants are corrosive and can be
dangerous to use. However, they are broad-spectrum disin
fectants and are also the most effective disinfectants in the
presence of dirt or low temperatures. Quaternary ammoni
ums are very effective as long as the surfaces to be disin
fected are not dirty. Disinfectants are effective only if
adequate time is allowed for contact of the disinfectant with
the surface. Exposure to sunlight and drying are also effec
tive disinfecting procedures.
Rodents, dogs, and cats have been incriminated as
sources of PR virus spread in a number of outbreaks. Ro
dents, pets, and birds also can transmit many other costly
diseases (See the table below). Therefore, excellent rodent
and bird control is necessary on a continuous basis. Rodents
are attracted to areas piled with rubbish, so keep areas
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