Cattle farmers use stomach magnets to trap swallowed metal

Swallowed metal can become lodged in the reticulum, a chamber of the bovine stomach that acts as a filter during digestion. Sharp pieces can pierce its wall, causing severe abdominal inflammation, or reach vital organs, including the heart. A magnet placed in this chamber attracts and holds metal fragments while food continues through the digestive system.

Farmers administer the magnet using a balling gun, a long tube fitted with a plunger. The operator inserts the end into the animal’s mouth, positions it beyond the second row of teeth and pushes the plunger to release the magnet. It then remains inside the stomach.

The magnet generally stays in place for the animal’s lifetime without disrupting digestion or causing discomfort or inflammation. Occasionally, an animal brings it back up, requiring another administration, but a single application is usually sufficient. At slaughter, years later, the magnet can be retrieved for reuse.

One incident described involved a calf on Carole Soule’s farm that died, possibly from hardware disease. Roofing materials and nails had recently fallen into its pasture during roof renovation. Soule, a co-owner of Miles Smith Farm in New Hampshire, is among the producers who say magnets protect cattle against this farm hazard.

Dan Athearn of Morning Glory Farm lent a Danish-made magnet with a protective plastic casing that had been manufactured years earlier. Most available models have no such covering. Both the encased and uncovered versions are described as effective at retaining metal fragments.

Pasture cleaning and hoof inspections for embedded nails remain necessary alongside the use of magnets. These maintenance measures address metal hazards on the farm, while the magnet holds fragments that cattle have swallowed.