Manitoba Agriculture, Food and Rural Initiatives
Colostrum
What is it?
Colostrum or “first milk” is produced in the initial secretions
of the mammary gland following the birth of offspring. Colostrum
is most commonly distinguished from whole milk because it
contains high concentrations of immunoglobulins (Ig), otherwise
known as antibodies. Antibodies are proteins which function to
identify and destroy disease-causing pathogens in livestock.
Colostrum is also a vital source of growth factors and
nutritional elements such as protein, fat, milk sugar, vitamins
and minerals.
Why is Colostrum Important?
Transfer of maternal antibodies across the placenta to the fetus
does not occur during pregnancy in cattle. For this reason,
calves are born with limited resistance to disease. Colostrum is
important because it provides calves with passive immunity until
their immune systems are developed and able to actively produce
antibodies in response to infection or immunization.
The main classes of antibodies present within colostrum are IgG,
IgM and IgA. Each antibody differs in structure as well as
responsibility. IgG, colostrum’s most predominant antibody,
functions to identify and demolish pathogens found within the
bloodstream as well as other parts of the body. IgM recognizes
and destroys bacteria solely entering the blood. IgA acts by
fastening to membranes that line various organs, such as the
intestine, and prevents pathogens from attaching and causing
disease.
Research indicates that calves obtaining sufficient levels of
antibodies from colostrum are less susceptible to sickness and
death caused by common infectious diseases including septicemia,
diarrhea and respiratory illness. Since colostrum is rich in
nutrients it is also a superior source of energy, protein,
vitamins and minerals. Calves utilize fat and lactose from
colostrum to instigate heat production and maintain a constant
body temperature. Vitamins and minerals are also important to
initiate metabolism and possibly assist in the development of
the digestive system. Non-nutritive components of colostrum such
as growth factors aid to develop and mature the digestive
system.
Factors Influencing the Success of Colostrum Feeding
The success of passive transfer of immunity via colostrum to
new-born calves is mainly dependent on three factors: quality of
colostrum, quantity of colostrum and timing. Colostrum quality
is directly linked to it’s concentration of antibodies. Quality
is always greatest the first-milking post-calving. Second or
later milkings of colostrum contain significantly lower Ig
concentrations because Ig transfer from the bloodstream of the
dam into the mammary gland typically stops by the time of
calving. For this same reason, cow’s leaking milk pre-partum may
have considerably reduced colostrum Ig concentrations. Antibody
concentration of colostrum is also a function of breed type and
lactation number. Beef cows typically have higher Ig
concentrations in colostrum than dairy cows. Additionally, older
cows generally produce elevated concentrations of antibodies
compared to first-calf heifers since they have been exposed to a
greater number of pathogens in their lifetime.A critical mass of
100 to 200 grams of Ig must be ingested and absorbed by the
new-born calf to attain passive immunity. Accordingly, calves
should consume a minimum of 2 liters of colostrum within their
first hour of life followed by an additional 2 liters over the
next 6 to 12 hours. Timing of colostrum intake is critical
because the intestines ability to absorb antibodies declines as
the calf ages. Intestinal absorption progressively lessens after
12 hours of age and complete gut closure typically results after
24 hours.
Natural suckling to accomplish passive transfer of immunity from
dam to calf can be relied on in beef cattle unless some
condition exists that is likely to decrease the success of this
process. If vigorous active nursing has not started within 2-3
hours of life, every effort should be made to supplement
new-born calves with the best source of colostrum via bottle or
tube feeding.
Alternative Sources of Colostrum for the Beef Calf
It is best to have colostrum on hand from your own herd if
possible, since using colostrum from other herds raises
biosecurity issues as well as differences in antibody
concentrations. It is important to know the operation and their
health management strategies before using their colostrum.
Colostrum replacement products are available in the event that
colostrum can not be collected quickly. Regardless of which
product you are feeding, it is important to remember that
colostrum replacer must deliver at least 100 grams of IgG for
absorption to the new born calf.
Storing Colostrum
Colostrum that is not fed within 2 hours of collection should be
refrigerated to control bacterial growth. Refrigeration at 4?C
in plastic containers maintains the viability of antibodies and
other components of colostrum for up to 7 days. For long term
preservation, colostrum can be frozen for up to one year with
little nutrient loss. The best method for storing colostrum in
the freezer is in 2 liter stackable, plastic containers or
freezer bags (be sure to double bag). Thaw colostrum slowly in
warm water (38?C) to preserve quality. Rapid thaw can damage and
reduce the efficacy of colostral antibodies. Colostrum can also
be thawed in a microwave set on “low” power. Microwave for short
periods of time and constantly pour off thawed portions.
Never pool together colostrum from different cows. This
practice, once believed to minimize the effect of low Ig
colostrum and increase volume available to calves, has a
negative effect on the acquisition of immunity. It also
increases the likelihood of disease transmission to calves
because multiple cows are represented in a single feeding.
References:
Besser, T.E. and Gay, C.C. 1994. The importance of colostrum to
the health of the neonatal calf. Vet Clin Food Anim. 10:
107-117.
Blomquist, N. 2008. The importance of colostrum for calves –
frequently asked questions.
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq8021
Kopp, J. 2007. Colostrum and milk replacers: Cattle production
for women seminar.
Lang, G. 2008. Factsheet: Colostrum for the dairy calf.
http://www.omafra.gov.on.ca/english/livestock/veal/facts/08-001.htm
McGuirk, S.M. and Collins, M. 2004. Managing the production,
storage, and delivery of colostrum. Vet Clin Food Anim. 20:
593-603.
Petrie, L. 1984. Maximizing the absorption of colostral
immunoglobulins in the newborn dairy calf. The Veterinary
Record. 114: 157-163.
Prepared By:
Kristen Bouchard
Animal Nutritionist
Manitoba Agriculture Food and Rural Initiatives
email:
Kristen.Bouchard@gov.mb.ca
