Genetics and Behavior During Handling, Restraint, and Herding - Genetics and the Behavior of Domestic Animals - page 145

investigate a shadow or puddle, they will usually step around or over it and
other animals will follow ( Hutson, 1980 ). Unfortunately, in a high-speed
slaughter plant, there is not enough time to allow the leaders to investigate
novel objects or areas of high contrast.
Emotionally reactive animals are often in a high state of nervous system
arousal due to the novelty of the situation, which makes them more vigilant
and likely to balk at small distractions in alleys and races that draw their
attention. A jiggling chain, people up ahead, a sparkling reflection on a piece
of metal, or air drafts and hissing exhausts blowing in their faces can all
cause the animals to stop ( Grandin, 1996 ; Grandin and Deesing, 2008;
Tanida et al., 1996 ). More placid animals will usually hesitate and look at
small distractions, but are more likely to keep moving. However, an area of
high contrast or something that looks out of place is more likely to cause
balking in nervous animals. In five different slaughter plants, the removal of
all distractions such as sparkling reflections, air drafts, and a presence of
people up ahead made it possible to greatly reduce the use of electric prods
( Grandin, 1996 , 2007; Grandin and Deesing, 2008 ).
Genetic Effects on Handling Facility Design
The first author has observed that the temperamental differences between
Brahman breeds (Bos Indicus) and European Continental breeds (Bos
Tauras) has had a substantial influence on the design of cattle handling facil-
ities in the United States. These differences in design evolved over many
years because ranchers used what worked. For example, in the northern
United States, when cattle are being sorted into groups by sex or weight, the
mostly placid British cattle are sorted in 3.5- to 5-meter-wide alleys by peo-
ple moving among them either on foot or on horseback. This method works
because animals with a calm temperament can be easily separated from the
group. Cattle with Brahman genetics are more excitable and have to be
sorted in a 70-cm-wide, single-file race with gates at the end leading to sepa-
rate pens. When Brahman cattle get excited, they engage in bunching behav-
ior and herd tightly, which makes it difficult to sort out a single animal in a
wide alley. Removing a single animal from the group is more difficult. It is
much easier to sort cattle with an excitable temperament through a single-
file chute. Hohenboken (1987) also commented that Brahmans behave differ-
ently in corrals and working facilities compared to B. taurus cattle.
CONCLUSION
Both genetic factors and the animal's rearing environment will determine
how an animal will behave during handling. Animals with a highly reactive,
excitable temperament will become more fearful and agitated when
confronted by sudden novelty compared to animals with a calm, placid