Researchers Examine One-Sided Imprint Training

Researchers Examine One-Sided Imprint Training

The team found that the foals that were not imprinted at birth were the easiest to handle from either side.

Photo: Christa Lesté-Lasserre, MA

Foal imprinting, or human handling of foals immediately after birth, is a contested topic amongst breeders, and French researchers are now looking at yet another "side" to this early training procedure's effects.

According to Alice de Boyer des Roches, a PhD candidate at the French National Institute for Agricultural Research and the VetAgro Sup veterinary school, and colleagues (behavior scientists in the animal and human ethology department of the University of Rennes), newborn foals receiving intensive tactile stimulation (the "Miller Method," (in which handling of a foal should begin immediately at birth and be repeated or expanded upon over days or weeks) on their right side only often turn out to be even more wary of humans than those imprinted on the left side only. And as displayed by a previous study by a Rennes research team, the foals that weren't handled at birth appear most at ease with humans.

"What we're seeing here is an additive effect of manipulation and the side of manipulation," said de Boyer des Roches, primary author of the study that revealed these results. "And that manipulation is being perceived more negatively when it's happening on the right."

In her current study, de Boyer des Roches and her colleagues tested early handling's effects on 28 newborn Arabian foals separated into three groups:

  • One group was stroked vigorously immediately after birth for one hour on the right side of their bodies only;
  • One group was stroked vigorously immediately after birth for one hour on the left side of their bodies only; and
  • The foals in the third group were not touched at all, but a human stood quietly in the stall for an hour immediately after birth.

When the foals were 10 to 14 days old, the researchers recorded the animals' reactions to humans approaching them. The team found that the untouched foals were the easiest to handle from either side. The group imprinted on their left side was easier to approach from the right side than the left side, and the group imprinted on the right side was the most difficult to approach, regardless of which side the person approached from.

"The hypothesis here is that tactile stimulation is not perceived in the same way on the right and left sides of the body, which explains why it doesn't cause the same consequences," said Virginie Durier, PhD, fellow behavior researcher at Rennes and co-author of the study.

The study, "Differential outcomes of unilateral interferences at birth," was published in Biology Letters in April 2011. The abstract is available online.

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About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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