Hormone May Be Early Livestock Disease Marker
August 29, 2000
Service scientists have found that a recently discovered hormone could act
as an indicator of disease stress in livestock. This hormone marker could make
it easier to keep some contamination out of meat processingand save
Increases in the hormone adrenomedullin (AM) appear to be
associated with some forms of infection in cattle, goats, pigs and sheep,
according to ARS research animal specialist Theodore H. Elsasser. He has been
collaborating with a National Institutes of
Health team of scientists led by Frank Cuttitta. NIH is interested in the
bioactivity and function of AM in human health and disease.
AM is a naturally occurring amino acid peptide hormone produced in
many tissues, including adrenal medulla, lung, kidney and heart, and it is
involved in many physiological and pathological processes.
For example, in ARS experiments, calves that harbored internal
parasites had more AM in their pancreatic tissue and blood than healthy calves.
So livestock producers may be able to use a test based on higher AM levels as a
screening biomarker for disease stress, indicating animals that may not be
acceptable for meat processing.
Both low-level, long duration parasite infections and intense,
short-term bouts can provoke higher AM levels. Elsasser thinks that it may be
possible to use AM levels to indicate the presence of other stresses like
metabolic diseases in addition to infection, although more investigation on
this application is necessary.
Currently, meat processors identify questionable carcasses based
on visual inspection and then subject them to microbial testing. In the future,
a rapid screening test for abnormal AM levels could make it possible for the
livestock producer to identify questionable animals before sending livestock to
Monitoring of AM levels may also give livestock producers the
opportunity to help sick animals recover from illness and make them safe for
processing, which would be a plus for the producer and the consumer.
ARS is the chief research agency of the
U.S. Department of Agriculture.
Scientific contact: Theodore H. Elsasser, ARS
Growth Biology Laboratory,
Beltsville, Md., phone (301) 504-8222, fax (301) 504-8623,