Genetics and Behavior During Handling, Restraint, and Herding - Genetics and the Behavior of Domestic Animals - page 124

cattle. Furthermore, Zavy et al. (1992) found higher cortisol levels Brahman
cross calves compared to crosses of Angus and Hereford. Stricklin et al.
(1980) report Angus cattle having higher cortisol levels than Herefords. In
Merino sheep, isolation stress increased plasma glucose 27% ( Lennon et al.,
2009 ). Pigs that squeal, jam in a chute, or were electric prodded had signifi-
cantly elevated blood lactate ( Edwards et al., 2010 ). Blood glucose and lac-
tate are simple, economical tests but must be used IMMEDIATELY after an
animal is subjected to restraint, isolation or handling.
Syme and Elphick (1982) used a commercial heart-rate monitor to study
heart rate and handling stress in merino sheep. The sheep were all neutered
males raised on the same farm. Temperament classifications were (1) quiet,
no response to being separated from the group, (2) jumpers, which attempted
to jump out of the pen after being separated, and (3) vocalizers. Quiet sheep
had lower heart rates compared to jumpers and vocalizers. Syme and Elphick
(1982) may have been measuring separation distress (PANIC) instead of
fear. McCann et al. (1988a,b) found a similar correlation between emotional-
ity scores and heart rate in horses. Tests of emotionality included response to
being herded, isolation, and being approached by people. Higher heart rates
were recorded in horses having strong reactions to isolation and being
approached by people.
Production Traits
Restraint and exit speed tests in cattle, sheep, and other animals have been
used to study temperament correlations with production traits. Animals with
fearful, reactive temperaments gain less weight, have more dark cutters, and
other meat quality problems ( Caf ´ et al., 2010; Hall et al., 2011; Holl et al.,
2010; Pajor et al., 2008; Voisinet et al., 1997 ).
Relationship between Fear and Attraction to Novelty
Highly reactive wild herd animals and highly reactive farm animals are both
attracted to novelty and fearful of it (see Chapter 1). Lawrence et al. (1991)
found that reactive (fearful) pigs are most attracted to novelty (seeking). Pigs
most likely to approach a novel bucket placed in their pen also showed the
most intense startle responses to a person stamping his foot. In an open field
test, highly reactive pigs also display behavior differences compared to non-
reactive pigs. Dantzer and Mormede (1978) found that highly reactive
Pectrain pigs walk around more in a novel arena compared to placid Large
White Pigs. Pictrain pigs also learn an active avoidance task quicker than
Large White pigs. William et al. (1964) also found breed differences in
learning active avoidance tasks between excitable Hampshire piglets and
placid Durocs. Hampshire piglets learn to avoid shocks quickly compared to
Durocs. The breed effect was greater than the effect of individual differences