by Heather Smith Thomas
The cow’s first milk is crucial to health and survival of the
calf. Colostrum serves as a gut stimulant to help pass the first bowel
movements, and contains a creamy fat (high in energy and easily digested--giving
high-energy calories for body heat and strength). A calf that gets
right up and nurses is more vigorous, and more able to stay warm than
one that hasn’t nursed. A newborn calf that has nursed will
often buck around, feeling good. A calf that has not yet nursed may
be more sluggish and easily chilled.
Especially important are antibodies in colostrum. The calf is born
with no immunity and must acquire temporary protection from his mother’s
antibodies via her colostrum. This passive transfer usually gives
protection until his own immune system becomes mature enough to start
producing its own antibodies. Temporary protection usually lasts three
to six weeks or longer, depending on the quality of the dam's colostrum.
A calf that gets no colostrum at birth is at risk for life-threatening
disease unless he gets an adequate substitute. If he doesn’t
nurse soon enough, he doesn’t get protection. When first born,
he can absorb the large antibody molecules through the intestinal
lining, before the pores close up.
Keith Bramwell, University of Idaho, says amount of antibodies a calf
can absorb into the bloodstream declines rapidly after the first hour
of birth. By four hours old, a calf has lost 75 percent of his ability
to absorb them. It does no good to vaccinate the cow ahead of calving,
if the calf doesn’t nurse soon enough to get the benefit from
antibodies she creates. The colostrum can give some temporary local
protection against gut infections (antibodies will inhibit pathogens
within the gut) but can’t get to the bloodstream to give protection
against systemic illness.
Making sure each calf nurses promptly after birth--especially in cold
weather, before his mouth gets cold and he quits trying--is the best
insurance you can give him against diseases he will soon face. Don
Hansen, D.V.M, with Oregon State University says the dam's serum antibodies
become concentrated in her udder during the last weeks of pregnancy.
But many factors can influence the quantity and quality of colostrum.
“These include age of dam, precalving nutrition, precalving
vaccination, calving difficulty and calf vigor,” says Hansen.
Undernourished cows have lower colostrum quantity, and heifers have
less antibodies in their colostrum than mature cows. Heifers are young,
their bodies are still responding to new antigens, and even when vaccinated
don't respond to vaccine as well as an adult cow. A heifer’s
calf’s immunity may start to wane after only three weeks, while
an older cows’ calf may have protection for a couple months.
A cow raised on your place has more immunity against pathogens the
calf will encounter than does a pregnant cow you purchase and bring
in from somewhere else. Pre-calving vaccination can help, but home-raised
cows often give their calves the best protection.
Ranchers can greatly reduce scour losses by hand suckling the calf
or milking the cow and tubing the calf if it hasn’t nursed on
its own within one hour. Stress can shorten the time in which a calf
can absorb antibodies. Cold weather, a hard birth, etc. make it even
more imperative to get colostrum into the calf immediately. ©
Frozen Colostrum for Emergencies
A cow with a lot of colostrum can be milked and the extra colostrum
frozen--stored in small plastic containers or snap-top freezer bags.
Antibody levels are highest at calving and decrease rapidly after
the calf nurses and colostrum is diluted with regular milk. The best
time to get extra colostrum is when the calf is nursing--taking a
quarter or two that he doesn’t need.
Colostrum should be frozen quickly and will keep for several years
without losing potency of the antibodies. When using frozen colostrum,
thaw it in warm water, not by direct heat or the microwave, or you
risk destroying the antibodies. Immerse the container in 110 degree
(F) water, and never heat the colsotrum itself to more than 104 degrees
(F); it should feel warm to your touch, but not hot. Colostrum should
not be thawed and refrozen.
A calf unable to nurse its mother can be given substitute colostrum
by bottle, stomach tube or esophageal feeder. A large calf needs two
quarts; a small calf can be given one quart. A smaller amount can
be used if you think it will “jump start” the calf and
you can get him nursing his dam: otherwise give the full amount.
