Preparing Newborn Pigs for Faster Weight Gains

By Ben Hardin
June 18, 2001

Newborn pigs may get off to a better start if given a one-time injection of an anti- inflammatory agent used in veterinary and human medicine. In repeated small-scale tests, pigs treated with dexamethasone grew about 12 percent faster in their first 18 days of life than did other pigs.

Dexamethasone is a synthetic version of a type of hormone called a corticoid that is naturally produced by animals under stress.

Agricultural Research Service animal physiologist Jeffery A. Carroll and his colleagues at the University of Missouri-Columbia now are beginning to test the one-time treatment’s long-term effects on pigs. These tests include measures of body composition at market weight, rate of weight gain and the amount of feed consumed per pound of gain.

Reducing the average time from birth to market by just one day could translate into an annual income boost of tens of millions of dollars for the nation's swine producers, says ARS animal physiologist Robert L. Matteri, formerly at Columbia.

If treated pigs’ faster growth persists, a pharmaceutical company might be interested in conducting additional tests. More tests would be needed in order for the company to apply for federal regulatory approval of dexamethasone injection as a treatment to enhance pigs’ growth.

Injected at the wrong time, dexamethasone could slow a pig’s growth, according to Carroll. The first hour after birth may be an opportune time to apply the synthetic stress hormone to program the pigs’ endocrine systems for lifetime efficient weight gain. In the experiments, pigs injected with the drug experienced no obvious behavioral effects and they started to nurse quickly.

Carroll decided to research dexamethasone after earlier experiments had provided insights on lasting effects of stress at birth. In those studies, he measured natural hormone and chemical levels of young pigs, some of which had been delivered by caesarian section. He concluded that, by preventing the stress of natural birth, surgical birth inhibited the pigs' growth.

ARS is the U.S. Department of Agriculture’s chief scientific agency.

Scientific contact: Jeffery A. Carroll, ARS Animal Physiology Research Unit, Columbia, Mo., phone (573) 882-6261, fax (573) 884-4798, carrollja@missouri.edu.