Human interaction with foals at a critical early developmental age appears to be a stressor, whereas positive human interaction with the dam creates a strong model for the observing foal, according to a series of ongoing research projects at the University of Rennes in northwestern France.

The team’s new findings are raising questions about the 15-year-old desensitization technique of imprinting and the common practice of guided suckling, according to Séverine Henry, PhD, professor of animal behavior at the university and co-author of the studies. Imprinting involves human handling of newborn foals in the first hour after birth. In guided suckling, foals are hand-led to their dam’s teats within that same hour.

Since 2004, the team of behavioral biologists has been leading comparative studies that focus on the short- and long-term consequences of various human intervention practices in the immediate postnatal period on foal behavior.

“Our most recent study has focused entirely on imprinting techniques, and what we found was that it really wasn’t very effective,” Henry said.

The results, parts of which were published in Developmental Psychobiology and the Journal of Comparative Psychology, reveal that foals handled by humans during the first hours following birth remained closer to their dams and appeared to be more cautious about approaching humans at several weeks and months of age than foals in a control group that had not been handled.

Human-handled foals were also less social with other foals and less likely to explore their surroundings or separate from their mothers, even at six months of age, Henry said.

By contrast, foals that had not been handled directly, but had witnessed gentle human handling of their dams, were more likely to trust humans, the studies showed.

“What we have discovered is that everything that the foals experienc