|
Read the
magazine
story to find out more. |
|
 Graduate student
Danielle Cary (left) and immunologist Susan Eicher feed a calf a fluorescently
labeled supplement that will enable them to determine where the supplement acts
to boost the immune system. Click the image for more information about
it. |
Anti-Stress Formula Gives Calves a Boost
By Don
Comis March 2, 2005
An "infant formula" for calves that may help them fight infection
from Salmonella and other microbes--especially during stressful
times--has been developed by Agricultural Research Service (ARS) scientist
Susan
Eicher.
The dietary supplement alters calves' immunity enough to help them
cope with transport stress, which appears to be among the worst sources of
stress early in an animal's life.
The formula contains beta-glucan from yeast cell walls and vitamin C.
Studies showed it reduced stress in Holstein dairy calves taken from their
mothers within 24 hours after birth and transported.
To mimic commercial operations, Eicher and colleagues took Holstein
dairy calves--usually 3 to 10 days old--on 6- to 8-hour trips every Monday, to
measure stress. They treated half of the calves in each truckload with one of
two versions of the experimental formula. Eicher is an immunologist in the ARS
Livestock
Behavior Research Unit at West Lafayette, Ind.
Formula-fed calves regained their appetites and resumed normal
growth--with improved nutrient utilization--faster than those not fed the
formula. They were also more active and had lower levels of fibrinogen, a liver
protein that typically increases with transport stress.
The formula seems to work with the mother's colostrum, a fluid
produced by the mother's mammary glands in the first hours after birth.
Colstrum provides nutrients as well as substances that help protect the newborn
animal against disease until the young animal's own immune system begins to
function. Calves given the formula had higher levels of immunoglobulins, which
are transferred in colostrum and are indicators of a good immune system.
Another possible connection to colostrum was that untreated calves
experienced less stress if they were trucked before or after the fourth day
following birth. According to Eicher, this may be because calves are making the
metabolic transition from colostrum to milk at around day four.
As part of an effort to find out exactly how the anti-stress formula
works, Eicher is now studying calves' immune cells under a microscope to see
where beta-glucan moves and where it accumulates.
Read more
about the research in the March issue of Agricultural Research
magazine.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.