How Are Magnets Used in Cows?

Cows are none too picky when it comes to eating. They often consume whatever is in their path without even chewing it. While this practice works for hay, grass and other vegetation, a cow can get into serious trouble if she ends up eating nails, staples, screws, wire, cans and other sharp metal debris. That's where magnets come into play.

  1. Purpose

    • Cattle owners use magnets in cows, appropriately called cow magnets, to help prevent hardware disease. This condition occurs when cows swallow metal objects while grazing. The metal debris ends up stuck in the first chamber of the cow's stomach. Cow magnets, which sit in that first stomach chamber, attract metal objects towards the magnet in the bottom of the chamber and away from the sensitive chamber walls.

    Hardware Disease Symptoms

    • Cows suffering from Hardware Disease will lose their appetite and have no interest in eating as the metal objects wedge themselves into the honeycombed walls of the stomach chambers. Dairy cows suffering from Hardware Disease produce less milk while other cattle become unable to gain any weight. The metal nestled in the chamber walls not only irritate and inflame the walls but can poke through the walls and injure the nearby lungs, heart and other organs. Holes in the stomach can also leak toxic digestive juices.

    Appearance

    • Cow magnets are long and thin, just the right size and shape for easily slipping down a cow's throat. The diameter ranges from about 0.5 to 0.75 inch and the length ranges from bout 2.75 to 3 inches. Most are cylindrical, but some are long, thin bars that are rectangular in shape. Ferrite magnets are a common material, sometimes with steel plates inserted along the length of the magnet to intensify the magnetic force. Some feature a polished or polyethylene coating.

    Using

    • Cattle owners place the elongated magnet in the cow's throat, and, after the cow swallows it, the magnet lodges itself into the bottom of the first stomach chamber. The cow regurgitates the other foodstuff out of the chamber back into its mouth to chew it properly and pass it along to the second stomach chamber, but the magnet stays put inside the chamber because of its heft and weight. One magnet works for the cow, usually lasting the cow's entire lifetime. Once a cow dies, cattle owners can remove the magnet, clear off the debris and use it another cow.

    Considerations

    • If a cow ends up eating a lot of metal objects, the cow magnet will fill up and become useless. It won't have any surface area left to attract more metal objects. At this point, the cattle owner has to make a choice. He can either have a veterinarian surgically remove the magnet to clear off the debris or he can slaughter the cow, even if he were planning to keep it alive for later slaughter. Since surgically removing a cow magnet is a costly operation, according to Florida State University, this often becomes a difficult economic decision.