(f'SC,, Range Cattle Station *- *:
?- 6 RCS69-2 May 1969
FRiSNT STATUS OF ErRCONDITIONING1 .,
MAY 0 1969
H. L. Chapman, Jr.2/
I.F.A.S. Univ. of Fl<
The concept of preconditioning beef calves reportedly -evoLve-
during the early 1960ts in the western area of the. United States. Since
the word first appeared in print there have been many articles written,
and meetings held concerning its meaning. There has been considerable.
divergence of opinion regarding preconditioning, depending.upon conditions
existing in different areas. The purpose of this report is to:summarize
available information about preconditioning, and to discuss its.importance
to Florida cattlemen.
What is Preconditioning?
Preconditioning refers to management systems wherein calves are weaned
on the farm before shipment and handled in such a way to enable the calf
to withstand stresses occurring at weaning. Essentially, it refers to
management systems which will reduce stress for 30 days prior to and 30
days after weaning and which will minimize weight loss, sickness and death
when weaned calves are placed in the feedlot or other management systems.
Preconditioned calves are expected to be:
1/ Presented at 1969 Beef Cattle Short Course, University of Florida,
2 Animal Nutritionist and Head, Range Cattle Experiment Station, Ona,
1. Dehorned and castrated before weaning.
2. Taught to eat and drink before weaning, or immediately afterward.
3. Vaccinated before weaninig.
4. Weaned before shipment.
5. Treated for grubs and worms. (optional).
6. Identified to show treatments received.
No one of the above factors is the total preconditioning program.
Some factors are more important in some areas of the country than in others.
Some cannot be applied to all ranches. Standardization is difficult, if
not impossible. However, many progressive cow-calf operations in Florida
have had management systems for years, which include many of the factors
desired in preconditioned calves. It is probable that such programs will
become more commonplace in Florida as management of beef cattle operations
continues to become more intensive.
How Important is Stress?
Animal health, stress and nutrition are intimately related. Disease
organisms may be present in animals without visual expression until
nutrition becomes inadequate and/or stress occurs that lowers the animal's
threshold of resistance, allowing the disease to result. All three factors
must be considered simultaneously,but stress often has an important
bearing on the animal's health and nutrition. Factors causing stress in
cattle include weaning, shipment, castration, dehorning, poor nutrition,
change of diet, vaccination, weather change, anthelmintics, parasites and
Stress is Particularly Important to Calves.
The two most critical periods for a calf are at birth before maternal
immunity has developed and at weaning after maternal immunity has
disappeared. Maternal immunity is developed by the calf from antibodies
in its mother's milk. This acquired immunity protects the calf for
the first three or four months of its life. This maternal immunity
disappears when the calf reaches four to six months of age. Unless
care is taken, the stress of weaning weakens the calf so that it is
susceptible to a wide variety of diseases. In many instances calves
are weaned directly onto a truck, 'hauled long distances without feed
or water for 24 to 72 hours and then dehorned, castrated, sprayed, wormed
and vaccinated. The result is often much weight loss, illness and
This has become more apparent during the past five or six years,
since increasing numbers of calves are being placed directly into the
feedlot at weaning. They no longer have a year or more to overcome these
shock treatments, but instead, are being placed on accelerated production
programs demanding rapid growth immediately after weaning.
The most economically important feedlot disease condition is the
shipping fever syndrome. This condition results in weight loss, decreased
feed utilization, extra labor and drug costs for care and treatment, a
1 to 2% death loss, and in cattle being on inventory an extra 10 to 30
days. These factors reportedly cost the feedlot operator 10 to 20 dollars
per head. The shipping fever syndrome is due to stress, followed by viral
and bacterial infection. Both viral and bacterial infections must be
Y/ Appreciation is expressed to G. W. Meyerholz, Extension Veterinarian,
University of Florida for help in preparing this section.
Disease control is not the total program of preconditioning.
Preconditioning is more than giving a few vaccinations. However,
due to the potential direct economic losses, disease control is a very
important part of the overall program and receives considerable publicity.
As mentioned earlier, calves acquire immunity to a number of
diseases from antibodies obtained from their mothers' colostrum the
first few days after they are born. There is some variation in
thinking as to how long maternal immunity protects the calf. This is
further confused by the facts that some calves develop immunity through
natural infections, that maternal immunity varies for different diseases,
that vaccination against diseases generally develops shorter-lived
immunity to bacterial than to virus diseases, and that stress may
precipitate latent or mild infections into acute diseases.
For example, colostrol antibodies against IBR begin deminishing in
the milk soon after birth. There is some variability in thinking as to
the exact age that antibodies no longer protect the calf against IBR.
However, vaccination against IBR has been given relatively early in the
calf's life with considerable success in giving long-lived protection
against this disease. On the other hand, maternal antibodies against
BVD are found in the milk for as long as six months after birth, but
apparently do not furnish protection for the entire period. While the
antibodies in the milk may not provide complete protection against BVD,
they may interfere with the effectiveness of vaccination, and it is
recommended that vaccination for BVD occur after the calf is six months of
age. Vaccination for PI3, an infectious agent involved in the shippirgfever
syndrome, develops. a short-lived, transitory.riinunity. It is recommended
that vaccination for PI3 be done..about 30 days before weaning.
Calfhood diseases argcaused by bacteria, viruses or parasites.
Those of most impQrtance are: -,*
1. Bacterial ,
a. Navel ill. .
b. Enteritis complex or scours
d. Calf diptheria
f. Pink-eye condition
j. Malignant edema
2. Viral diseases.
a. Infectious bovine rhino.tracheitis (IBR).
b. Bovine viral diahrrea (BVD)
c. Parainfluenza 3 (PI-3)
3. Parasite diseases (not of major importance from birth to
weaning, under good management)
a. Lice .
c. Liver fluke
d. Lung worms
f. Gastro-intestinal worms
Immunization vaccination programs should not start until after
maternal antibodies have disappeared. Vaccination will not be effective
for animals with maternal or passive immunity for the disease being
vaccinated against. It is also important to remember that immunity
does not occur immediately., Although antibodies begin'to develop
within a few days, it takes three to four weeks after vaccination to
develop adequate protection. This means that if immunity is desired at
weaning, vaccination should occur three weeks or more prior to weaning.
Variations occur in thinking as to the age calves should be
vaccinated. Your veterinarian should be consulted to determine what
vaccinations are needed in a particular area, and when they should be
given. It has been repeatedly demonstrated that, where needed, proper
immunization programs will result in fewer deaths, faster gains, and
more profit. In areas of the country where comprehensive immunization
programs are needed, the following program has been suggested:
1. Four months of age.
a. Brand, dehorn, castrate.
b. Vaccinate for IBR, leptospirosis, blackleg, malignant
edema, and give injectable vitamin A.
2. Six to eight weeks before weaning (six months of age, or more).
a. Vaccinate for BVD and for PI3 if a killed vaccine is to
be used. Give injectable vitamin A.
b. Dehorn,i if needed.
3. At weaning.
a. Revaccinate for PI3 if a killed vaccine was used, or
vaccinate with a modified live virus PI3 vaccine.
Revaccinate against blackleg and malignant edema if
in an infected area or if calves received their first
shot before four months of age.
Another very important factor to consider in any immunization
program is the health and nutritive status of the calves and the
amount of stress present when vaccinated. It has been observed that
if calves are in the incubative stages of BVD or P13 infection, the
stress of vaccination apparently precipitated an acute infection which
otherwise might have remained in the passive state. Cattle given BVD
vaccination may develop a marked leucopenia and, while they may develop
resistance to BVD, they may become more susceptible to shipping fever
and other diseases. Malnutritioned cattle will be less apt to withstand
the stress of vaccination than calves in a good nutritional status.
Stress, such as that experienced at weaning or during.shipping, may
precipitate latent or mild infections into acute disease.
For immunization programs to be most effective the following
should be done:
1. Vaccinate at proper age.
2. Have cattle in good state eof nutrition when vaccinated.
3. Vaccinate for proper disease with proper vaccine.
4. Handle vaccines properly.
5. Manage animal properly.
6. Identify treated animals.
Long-term nutritional objectives are to provide calves proper
nutrition for growth. However, of more immediate importance at
weaning is a short-term objective of preventing an interruption of
rumen activity, due to a radical diet change or a24 to 72 hour
starvation period immediately after weaning. If a calf goes 24 hours
without eating, rumen changes occur that are difficult to overcome:
1. Fermentation capacity decreases 85 to 95%.
2. Bacteria population falls 25 to 50%, or more.
3. Protozoa almost completely disappear.
4. Rumen volume decreases approximately 50%.
5. The balance of rumen microbes is upset.-
6. Rumen pH falls.
7.; At the end of 48 hours of starvation, the rumen is
almost non-functional in the normal sense.
If cattle have been 24 to 72 hours without eating, care should
be taken to provide them a proper ration to stimulate rumen activity
and redevelop the proper rumen microbe population. Avoid feeding
high-concentrate rations after starvation periods. This type of feed
can cause a rapid buildup of lactic acid in the rumen which will cause
rumen pH to further decrease, killing many beneficial bacteria and
causing the normal population of rumen microflora to be further upset.
When this'occurs, lactic acid will be absorbed with the blood stream
faster than it can be utilized, causing a buildup of lactic acid in the
blood and acidosis. This causes dehydration, loss of appetite, metabolic
disorders, rumen dysfunction and possibly death. Research has indicated
a high-roughage.ration or a 45% roughage: 55% concentrate ration is
good for reestablishing the rumen microbial population after 48 to 72-
hours of starvation. The inclusion of 300 mg. of antibiotics in these
rations has been reported to retard reestablishment of rumen microflora
In order to help prevent rumen interruption, calves should be
taught to eat and drink, preferably before weaning. This is not easy
to do under the management practices followed by the majority of Florida
cattlemen. However, there are several options which may be considered:
1. Creep feed calves last 30 days before weaning for the
purpose of teaching them to eat, or
2. Wean calves into a good pasture, give a dry feed,
and have a few "teacher steers" with the group to teach
the new calves how to eat, or
3. Wean into a drylot with ample hay, feed and.water.
A management program should be utilized at weaning to reduce or
eliminate the starvation of calves for 24 to 72 hours after weaning. It
is important to eliminate this type of starvation period during shipment.
It has been shown that the incidence of shipping fever is directly
related to the length of time in shipment. The stresses of shipment,
environmental changes and dysfunction of the rumen due to starvation or
diet changes can all cause latent or subminimal infections to become
acute diseases. If it is not possible to eliminate a starvation period,
cattle should be rested and refed on arrival at their
destination and their rumen function returned 1to normal before
subjecting the calves to the stress:of vaccination, dehorning,
castration and other needed treatment.
One of the major problems in preconditioning programs is the
development of a simple yet adequate identification system that will
tell the history of any given animal. This is very important when'
animals are grouped from many sources. *The identification- system
needs to tell:
1. Origin of animal.
2. Individual number of animal.
3. Whether or not the animal is preconditioned.
4. Treatments given before and/or at weaning.
Many systems have been tried. None have been completely successful.
One system which has been used involves putting a tag in the. calves ear
before shipment....The first two digits of the number tell the origin
of the animal, the third number. indicates whether or, not the animal is
preconditioned and the remaining digits are used for animal identification.
Different colored tags can be-used to indicate the degree of preconditioning.
The tag can have numbers on the back describing the treatment given the'
Animal identification is a vital requirement for a successful
preconditioning program if preconditioned calves are to be properly
merchandised. It is extremely important. that all background information
be available to.the buyer,
. ... :. 1 7 r 1,,
One of the recommendations for preconditioningg programs
is that calves should be weaned about 30 days before they are shipped
to a buyer. Management during this 30 days should accomplish the following:
1. Calves are taught to eat and drink and become adapted
to new diets.
2. Opportunity is provided to separate good and bad calves.
3. Calves recover from.stress:of weaning.
4. Time is provided for development of immunity.
5. Opportunities are provided to better merchandise calves.
Management practices should include a number of steps which are
important whether or not preconditioning is followed:
1. Castrate, brand and dehorn calves before weaning.
2. Give necessary vaccinations to allow immunity to
develop before weaning.
3. At weaning, avoid putting calves in dusty environment.
4. Use all practical sanitary practices.
5. Teach calf to eat either by creep feeding before weaning
or immediately after weaning.
6. Feed a simple feed containing adequate protein, energy,
vitamin A, phosphorus, copper and cobalt. Provide
ample roughage. Use antibiotics first 10 to 14 days, except
after a 24 to 72 hour starvation period. Do not use urea
until after calveshave learned to eat and are adapted to
the new diet.
7. Hand feed daily to insure adequate observation of calves.
8. Have good employees handling calves.
9: Handle calves quietly and with as little disturbance
10. Treat any abnormal animal immediately.
11. Have adequate hospital facilities.
12. Grub treatment is recommended.
13. Routine internal parasite treatment is not recommended
unless need exists.
14. Use TLC (Tender, loving care).
One of the most important aspects of preconditioning is the
economics involved. The cowman wants to know how much preconditioning
he should do.. Will he receive a bonus for preconditioned calves?
Should he invest in facilities :to.precondition calves? The feeder,
on the other hand,.wants the calf to. be weaned at least three weeks
and preconditioned.before he buys:them. Thereis a reluctance to pay
for the extra service for fear he may not get what he is paying for,
or he may feel that all preconditioning steps are not necessary, or he
may question the way the vaccines, etc.-were given. There are a number
of problems involved. Preconditioning programs are best suited for
private negotiations between cattleman and buyer nid must be based on a
mutual trust and respect being developed.
At a recent meeting in Wyoming, the following economic data for
units of 100 calves were presented by a cattleman who preconditioned
his calves that were shipped to a midwest feedlot. The clves gained
40 pounds during the. 30. day post-weaning period:
400 lb. calf @ .30 $120.00
Death loss @ 1/2% ...60
Washout calves @ 1/2 value .60
Interest on calves @ 7% .70
Freight on additional 40 lbs. @ 1.50 cwt .60
Fixed cost (Facilities, etc.) 3.00
Yardage for 30 days @ 6 1.80
Combiotic fpr 4% of calves .02
Vaccination and parasite control 3.59
Feed costs 8.09
At the end'of the 30-day preconditioning period, the cattleman
had slightly more than 31 invested in his steers. Costs will vary
from state to state and from ranch to ranch. However, the above figures
present an example that may be used for comparison.
What Will Preconditioning Mean to the Florida Cattleman?
The concept of preconditioning has received widespread interest
during the few years it has existed and, while there are problems, it
is very probable that the practice will become more widespread. Feeders
will become accustomed to using preconditioned calves. Florida cattlemen
will find they can develop reputations for preconditioned and backgrounded
calves. As the concept spreads nationwide and becomes accepted and
expected, it is quite probable thatprice differentials will exist between
preconditioned and non-preconditioned calves.
As mentioned earlier, the loss from shrink, feed utilization and
efficiency, plus a 1 to 2% death loss in prevailing management practices
reportedly cost feedlot operators $10 to $20 per animal. As a result,
feedlots are developing record systems to tell them which groups of
cattle do well and which do poorly. Florida cow-calf producers will
be faced with the fact that their reputation will be built on the way
their cattle do in feedlot or in grass-fattening.programs.
As management systems continue to become more intensive, Florida
cattlemen will find that they will be carrying out many of the steps of
preconditioning as normal management policy. Many do this at the present
time. It will require very little effort for these people to precondition
calves. Some cattlemen (particularly the smaller ones) may find their
program not easily adapted to preweaning calves because they will not be
able to hold their calves for 30 days after weaning. Many of the other
steps in preconditioning calves will be easily carried out.
Each cow-calf operator should examine the potential that pre-
conditioning has for his operation to determine the program best suited
to his needs.
Changes are occurring in.the cattle industry of this country.
Feedlots are.evolving from the small, on-the-farm type that used to
be common in the midwest, to large, integrated operations.: Feedlots
continue to grow in size. They are feeding a younger animal which is
brought from heterogenous ,conditions and sources.' Many cattle are
obtained directly from the producer and many may pass through several
auctions or. commission buyers before they arrive in the feedlot.
Simultaneous with this feedlot growth and development, cow and calf
management is facing changes. Cattle populations are increasing and
management practices are becoming more intensified, resulting in
increasing problems from parasites and diseases. Paradoxically, while
some management practices have been intensifying, others have not.
Labor insufficiencies, inherent physical limitations or the way cattle
are handled often result in little, if any, immunization, dehorning,
castration, etc.- before cattle are weaned. When the calf is weaned,
it is often placed on a truck, spends 24 to 72 hours in shipment and
when it arrives at its destination it is confronted with a desire on
the part of the buyer to give the calf everything it needs vaccination,
dehorning, castration, worming, branding, etc. immediately. It is
often put into crowded pens that may be next to other cattle, or that.
have been recently vacated by other cattle. The calf has been subjected
to a multitude of stresses at the time in its life when immunity to
disease is lowest. The result is sickness and mortality.
The concept of preconditioning usually emphasizes the interval of
time immediately adjacent to weaning, but it is vital to emphasize the
importance of the overall management program for the calf from birth
until the animal is placed in the feedlots. It is important to recognize
that vaccination creates much stress on calves, and when this is augmented
with other stresses, favorable results may develop. Calves should be
vaccinated when stress is the least and after maternal immunity has
disappeared. The stress of castration haS been related to the incidence
of respiratory infection, and it is suggested that this be done before
weaning if calves are to be sold to feedlots. Preconditioning is in
reality a management program that reduces disease by reducing stress.
The degree to which Florida cattlemen utilize preconditioning will
depend on their individual situation. There are many unanswered questions.
For example, how much better do preconditioned calves do in the feedlot?
Will the feedlot operator pay more for preconditioned calves? What
management practices are most important for ranches and feedlot men to
follow to reduce stress? What is the beet way to identify preconditioned
calves? These and many more questions must be answered before the
concept of preconditioning is fully effective. Also, it is important to
realize that after all the steps of preconditioning are followed there
will still be cattle losses. It is not a magic, cure-all. However,
preconditioning incorporates many management practices which are already
followed by many progressive cattlemen and which will become more
common place as the cattle industry continues to grow. It is a step
forward in management which will become more widespread as better communication
develops between the rancher, the buyer, the feeder, the animal nutritionist,
the veterinarian and all other people involved in beef cattle production.
The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University