Behavior Genetics of the Horse (Equus caballus) - Genetics and the Behavior of Domestic Animals - page 240

Six Months Old
Handled foals were observed on pasture with their mothers and the other
mares and foals. Handled foals appeared more dependent on their mothers.
They interacted more with their mothers than with the other foals, and
played less (especially social play). Handled foals also explored “new”
objects in the paddocks less (such as an unfamiliar, motionless human) com-
pared to control foals. Only three out of the nine handled foals approached
the unfamiliar human, while all of the control foals approached and investi-
gated the human. All of the observed differences between the handled foals
and control foals involved social

emotional behaviors. Other behaviors
(exploring, moving around, resting, self-grooming, etc.) did not differ from
the control foals.

Seven Months Old (Weaning)
Following separation from their mothers, both control and handled foals
experienced similar levels of stress. Increased vocalizations and aggres-
siveness toward each other was observed in both groups, which indicated
that the social stress of weaning was similar in both control and handled
foals. However, after the second day, emotional reactions of the control foals
decreased, while high levels of vocalizations in the handled foals continued.
Handled foals also engaged in less solitary or social play.

One Year Old
Both handled and control foals were separated and housed in same-sex
groups. Most normal activities of the foals were not different. However, the
experimental foals tended to withdraw socially, spend more time at greater
distances from their peers, and exhibit more aggression. Control foals also
displayed almost three times more friendly, positive gestures toward each
other, while handled foals displayed more fighting, fleeing, or submissive
behaviors. In this study, differences between the neonatal experiences of the
foals revealed short-, medium-, and long-term effects of early experience on
attachment and social competence later in life. As Henry et al. (2009) states,
“These results underline the importance of this early stage for appropriate
social development, despite later experience with peers.”
All the studies reviewed here show that forcefully handling foals can
have various effects on behavior, mostly negative. The negative effects of
intensive handling may be more harmful in highly reactive breeds such as
Arabians and Thoroughbreds. In any case, foals that are not handled may
also present a problem. At some point they need to be trained to accept han-
dling for hoof care or health care. When these procedures become necessary,
forcing foals may cause undue stress and influence the way they respond to
handling in the future. A practical and easy way to teach foals to accept han-
dling by people without making them fearful is needed.