Biology Reference
In-Depth Information
zone when moved the first time by a man on foot (
Grandin and Deesing,
2008
).
Christensen et al. (2008)
found that habituation to a novel object is
stimulus specific. Horses tested with balls, boards, cones, or boxes were less
fearful when all the objects were the same color. The first author hypothe-
sizes that animals are sensory-based thinkers and remember objects as spe-
cific pictures (
Grandin and Johnson, 2005
).
Temperament and Strength of Emotional Responses
are Highly Heritable
Temperament in cattle is highly heritable. The heritability estimate of tem-
perament in dairy cattle is 0.40 (
O'Blesness et al., 1960
), 0.53 (
Dickson
et al., 1970
), and 0.45 (
Sato, 1978
). In beef cattle, the estimates are 0.40
(
Shrode and Hammack, 1971
) and 0.48
0.44 (
Stricklin et al., 1980
). The
numbers of vocalizations in sheep isolated from flockmates during testing is
highly heritable (
Boissy et al., 2005
). The trait of fear of humans is also
highly heritable (0.38) (
Hemsworth et al., 1990
). Despite the abundance of
evidence indicating that individual differences in temperament are geneti-
cally influenced, behavioral genetics research has more to offer the study of
temperament than estimates of genetic influence. Environmental contribu-
tions to temperament are equally important, namely, does temperament
change across age and through experience? Intuitively, one might guess that
as an animal matures and becomes more interactive with increasingly diverse
environments, the role of genetic factors on temperament might diminish.
Although limited research has focused on whether temperament can be mod-
ified,
Petherick et al. (2009)
found that fear of people, flight speed, and the
amount the cattle moved around a test arena was reduced by good handling.
Field Observations on Breed Differences in Cattle
and Sheep Behavior
Cattle with Brahman genetics are generally considered “flighty” compared to
breeds with British genetics such as Angus and Hereford. However,
Brahman cattle are more inquisitive and investigate or follow a person or a
dog. The tendency to follow a person is much greater in Brahman compared
to British or European Continental breeds.
Hohenboken (1987)
found
Brahmans can become extremely docile if handled gently. The first author
has observed that Brahman cattle seek stroking from people more than
Herefords. In Australia, a common practice used to move groups of
Brahmans is allowing them to follow a person.
The author's hypothesize that Bos Indicus breeds may have stronger
SEEKING and possibly stronger PANIC (separation distress) compared to
Bos Taurus cattle.
Murphey et al. (1980, 1981)
discussed behavioral differ-
ences between several breeds in flight zone size, and the tendency to
Search WWH ::
Custom Search