Genetics and Behavior During Handling, Restraint, and Herding - Genetics and the Behavior of Domestic Animals - page 141

reared with assorted objects to play with, straw bedding, and daily petting
were more willing to approach a novel object or novel person compared to
pigs reared in barren pens. Environmental enrichment made the pigs calmer
and less reactive, and they startled less when a person suddenly jerked upon
the gate to their pens. Environmental enrichment also makes pigs more
willing to walk through a single-file chute ( Grandin, 1989; Pederson, 1992 ).
Less prodding was required for the pigs from the “enriched” environment.
Dudink et al. (2006) investigated whether announcement of an environmen-
tal enrichment, more than enrichment alone could facilitate play behavior
and reduce weaning stress. A sound cue was paired with environmental
enrichment with a 30-second delay in which anticipatory behavior develops.
Results indicate that announcement of enrichment and not enrichment alone
increased play behavior, decreased aggression before and after weaning, and
reduced the amount of injuries after weaning.
The first author has experience training market-weight pigs with
excitable genetics to drive quietly at the slaughter plant. To facilitate han-
dling and adaptability to commercial conditions, the training is done on the
farm during the entire finishing time (fattening period). She found that by
walking through the pens in a random pattern each day (10

15 seconds per
pen) and training the pigs to move away in an orderly manner, the pigs
learned to get up and flow around her as she walked through the pen. In this
manner pigs are taught to be driven quietly by people instead of learning to
follow them. However, Grandin cautions the person walking the pens not to
frighten the pigs. The idea is to teach pigs to become accustomed to people,
to get up and move when people enter the pen, and not get upset and pile
up. Walking the pens is especially beneficial for lean hybrids with nervous
temperaments. Pigs differentiate between a person walking through their
pens and a person walking in the aisle. This is why it is essential for a person
to enter the pen and walk among the pigs. Further studies have shown that
getting pigs accustomed to walking in the aisles and other handling proce-
dures improved ease of handling ( Geverink et al., 1998 ) and ( Abbott et al.,
1997 ). Pigs with practice moving through alleys and a ramp were easier to
move through them in the future ( Lewis et al., 2008 ).

Excellent Memory of Aversive Experiences
Cattle, sheep, and other herd animals have excellent memories and remember
aversive handling experiences ( Grandin et al., 1986; Hutson, 1980, 1993;
Pascoe, 1986 ). For example, Hutson (1980) found that sheep subjected to
aversive procedures were reluctant to re-enter the test facility six months to a
year later. Pascoe (1986) also found that dairy cows that had received
shocks, remembered the shocks and showed higher heart rates when returned
to the facility. Previous rough handling also makes dairy cows reluctant to
enter a milking parlor ( Seabrook, 1987 ). Cows previously handled in a gentle