Behavior Genetics of the Horse (Equus caballus) - Genetics and the Behavior of Domestic Animals - page 253

three times per week for 10 minutes. At 6, 9, 12, 18, 21, and 24 months of
age, the study recorded behavioral observations in a human-approach test per-
formed in the home environment. At 12 and 24 months of age, the study
recorded behavioral observations in a novel arena test followed by a human-
approach test in a novel arena. Single-housed horses approached sooner and
were more easily approached by a human in the home environment, but not in
the novel environment. Single-housed horses also expressed less restless
behavior, more explorative behavior, and less vocalizations in the novel envi-
ronment, but not in the home environment. Handled horses also reacted less to
the novel environment. Results indicate that handling during the rearing
period is a means of avoiding potential dangers associated with handling
young horses in novel environments. Horses reared alone were reluctant to
approach a person in the novel environment and moved around more in the
novel arena. Visser et al. (2003) tested 41 young horses in four behavioral
tests: a novel object test (lowering an umbrella from the ceiling), a handling
test (crossing a bridge), an avoidance-learning test (avoiding a puff of com-
pressed air), and a reward-learning test (choosing a manger to receive a food
reward) during the first 2 years of life. Behaviors during each test were
recorded, i.e. locomotion, position relative to the novel object or bridge, pos-
ture of head and tail, latency times during the novel object or bridge test, and
vocalizations. At the age of three, personality traits identified earlier (tail held
high, latency time to touch a novel object, standing still in front of the bridge)
correlate with early training in jumping performance. The study shows that a
large part of jumping performance can be predicted by personality traits evalu-
ated earlier in life. Momozwa et al. (2003) used a questionnaire survey to
assess caretakers' impressions of temperament in 86 riding horses. The
five-point questionnaire revealed three independent factors that they called
“anxiety,” “novelty seeking,” and “understanding.” A balloon reactivity test
verified the reliability of the survey. Introducing each horse to balloons
revolving in the center of an unfamiliar arena and recording heart rate for
5 minutes revealed that horses evaluated as “highly anxious” by caretakers
had higher heart rates and defecated more during the balloon test. Also, horses
evaluated as having problems with ordinary care or training had higher heart
rates, and those evaluated by the survey as having a “long adaptation time to
adapt to unfamiliar objects” were unwilling to touch the balloons. Results sug-
gest that questionnaire surveys are a good way to assess temperament traits—
especially those related to anxiety. Hausberger et al. (2004) used three behav-
ior tests and a learning/memory test on a sample of 702 horses tested at 103
different sites. To establish precise genetic origin, the study used only regis-
tered horses. Study results show that determination of behavior/temperament
traits varies differentially with genetic influence (see our discussion of this
study in the introduction to this chapter). Christensen et al. (2005) recorded
heart rate and behavioral observations to stationary novel visual, olfactory,
and auditory stimuli on 24 untrained stallions. The stallions were habituated to