Pre-Weaning Vaccination of
G. Lien, DVM
Quality Beef (Born and Raised in the USA)
for the retail meat counter or restaurant begins at the ranch
under the care of a good mother cow and with the supervision
of a conscientious producer. Maintaining optimal health
throughout the growing and feeding periods requires a mix of
good genetics, proper nutrition and vaccinations to prime and
enhance the immune system. Pre-weaning vaccination at the
appropriate age of the calf becomes a valuable tool to help
prevent respiratory disease in the feedlot and the resulting
decreased feed efficiency, lower weight gains and a lesser
quality carcass grade.
herd health program developed with assistance of the local
veterinarian will be designed to minimize the exposure and
infection by the viruses and associated bacteria that are
involved in BRD (Bovine Respiratory Disease).
A healthy, adequately immunized mother cow will provide
maternal antibodies (passive immunity) to the calf through the
colostrum at birth. The calf’s passive immunity gained from
the maternal antibodies begins to wane around the age of five
to six months. In a healthy closed herd on the range, the
calf’s exposure to the BRD organisms will be minimal and
there will be little opportunity for the calf’s immune
system to develop an active or acquired long lasting immunity.
The result is an increased disease susceptibility (morbidity)
and mortality in the feedlot.
particular concern is the wide spread exposure to the BVDV.
Protection of the developing fetus is not consistently
obtained by regular vaccination of the mother cow. Exposure of
the fetus during the first 100 days of gestation may result in
a BVDV PI (persistently infected) calf. This individual may
not always appear as the unthrifty, chronically sick smaller
calf, however it will constantly shed BVD virus and be a
continual source of virus exposure to the individuals in the
herd that do not carry a protective immunity. The BVD virus
acts as an immunosuppressive agent. BVDV infection in
conjunction with any of the other BRD organisms usually
results in increased severity of symptoms, poorer response to
therapy and increased mortality. Identification and removal of
the BVDV PI individuals is important to the success of the
herd’s preventive health program.
combined stresses of fall weather changes, weaning,
transportation, drastic changes in diet and confined
co-mingling with animals from a wide geographical area, can
easily overwhelm the calf’s waning passive immunity. The
timing of Pre-Weaning Vaccination is critical in that the
vaccine antigens should be administered at an age when the
maternal antibodies are low enough to not interfere with the
development of an active humoral and cellular immune response.
The level of protective immunity may not be adequate until
21 days past the last administered vaccine, so the
Pre-Weaning Vaccinations should be administered at least 21
days before the stresses of weaning and shipping begin.
Potential post-vaccination reactions and weight loss due to
handling are minimized when the calf remains with the dam on
pasture. The duration of active immunity stimulated by
vaccination at branding may also be short-lived due to the
interference by the maternal antibodies. And the four month
time span between the vaccine administered at branding and the
vaccine administered at pre-weaning, may be too long for an
adequate anamnestic response to provide protective antibodies
of long duration.
must be given to the particular vaccine indications and
precautions. Manufacturers advise against the administration
of modified live viral vaccines to calves nursing pregnant
cows. This is due to the concern that potential shedding of
the vaccine virus may abnormally affect the developing fetus.
Attenuated viral vaccines or killed virus vaccines are
recommended for the calf nursing the pregnant cow. However,
the killed virus vaccines and most bacterins or toxoids
require a second or booster dose administered 2 to 4 weeks
after the first vaccination, in order to provide a protective
immunity, as indicated by the product label.
to handle the vaccines according to label instructions:
administer in the neck region (preferably subcutaneous if
allowed according to the label), maintain the products at the
proper cool temperature, avoid exposure to bright sunlight and
insure that the syringes are free of disinfectant
contamination. Good working facilities allow the animals to be
processed quietly and efficiently, thereby reducing
physiological stress. Adverse handling can result in elevated
levels of cortisol (a hormone produced during the ‘fight or
flight’ response to fear), which interferes with the normal
function of the immune system. Care in handling the animals
and the vaccine products will help prevent the so-called
“vaccine failures”. Consult with and follow the advice of
your local veterinarian.
can not overcome inappropriate husbandry practices. Vaccines
are a preventive tool in a complete management program. The
immune system requires a balance of nutrients – energy,
protein, water, minerals and vitamins – in order to mount a
good protective immune response.
Depending upon the geographical area and the severity
of drought, supplementation of the trace minerals (copper,
zinc, selenium, manganese) and Vitamins A and E may be
necessary for the calf to maintain its genetic growth
potential and be able to physiologically produce protective
antibodies. This supplementation may be required throughout
the entire growing season or at a minimum of sixty days prior
to weaning, as the forage quality decreases. Realize that with
our current genetics, calves have the potential to gain 2.5 to
3.0 pounds of body weight per day from birth to weaning –
inhibiting this potential through inadequate nutrition may
also limit the potential protective immune response.
(Infectious Bovine Rhinotracheitis virus), PI3
(Para-influenza virus), BRSV
(Bovine Respiratory Syncytial virus), BVDV
(Bovine Virus Diarrhea virus) and the bacteria organisms; Mannheimia