Genetics and Behavior During Handling, Restraint, and Herding - Genetics and the Behavior of Domestic Animals - page 138

select for calm temperaments. Significant improvements in levels of fearful-
ness have been achieved by selecting populations against these traits.
Selective breeding makes a group of animals more homogenous. Hair whorl
position is likely to be more variable and have a significant relationship with
behavior in groups of cattle or horses with more heterogeneous diverse
genetic backgrounds.
Hair Whorl Height and Vigilance
Animals with hair whorls located high on the forehead may have high ner-
vous system reactivity, increased fearfulness and emotionality, highly acute
senses, stronger orienting responses, and vigilance. A low hair whorl may be
related to reduced vigilance and a reduced reactivity and fearfulness. Florcke
et al. (2012) observed that Red Angus beef cows with high hair whorls
were more vigilant when their newborn calf was threatened by an approach-
ing vehicle. Cows looked up and oriented towards the vehicle when at a
greater distance compared to cows with lower hair whorls. In Brazil, cattle
with high hair whorls above the eye exited more rapidly from a restraining
chute Bueno Ribeiro et al. (2012) , and struggled more in a scale. Brazilian
cattle have had much less intensive selection for temperament.
In cattle and horses, fine-boned, slender-bodied animals have a highly
reactive temperament, a high hair whorl, and are more likely to have an explo-
sive reaction when suddenly confronted with a novel stimulus that moves
suddenly. Heavy-boned, muscular animals are more likely to have a calm tem-
perament and a low hair whorl. Holstein dairy cows lack heavy muscling but
fit the above criteria because they are heavy boned. We began to speculate
about two separate genetic mechanisms influencing temperament after the
first author visited the Lasater Beefmaster herd in 1996. Lasater's cattle been
closed to new genetics for 60 years, and subjected to a unique set of selection
pressures. Lasater (1972) selected his cattle using the natural principle of sur-
vival of the fittest. Heifers unable to give birth unassisted or to protect their
calf from coyotes were culled. However, Lasater wanted commercially useful
cattle so he also selected for temperament and carcass traits. The Beefmaster's
breed is half Brahman, quarter Hereford, and quarter Shorthorn. Heifer's
calves were selected as herd replacements if they willingly ate a food treat off
a stick held by a seated person. Tom Lasater's son Dale explained how they
selected for temperament. Instead of using sudden aversive novelty (such as
restraint) as a temperament test, they assessed temperament of hungry, newly
weaned calves by sitting in the pen with them. Calves that failed to eat from a
person's hand after two days were culled. When the herd was first started,
about a quarter of the calves were culled. Today only 1% are culled for tem-
perament (Dale Lasater, personal communication, 1996).
Lasater's selection criteria resulted in cows that are very protective of
their calves, but extremely tame and seek contact with people. It is unusual