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Anti-Stress Formula Gives Calves a BoostBy 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.