Agriculture Reference
In-Depth Information
Behavioural data recorded during and after these various husbandry procedures as well
as endocrine data suggest that they are painful, with surgical castration inducing the
most severe pain (Hay
et al.,
2003; Marchant-Forde
et al.,
2009; Noonan
et al.,
1994;
Prunier
et al.,
2005; Sutherland
et al.,
2008; Torrey
et al.,
2009; White
et al.,
1995). In
European countries, pig producers have started to use a pharmacologic agent to relieve
pain at castration using an analgesic injection (meloxicam) before castration and/or a
general anaesthesia performed by CO
2
or isoflurane, or a local anaesthesia with lidocaine
(Anonymous, 2010; Fredriksen
et al.,
2009). However, even if those methods mitigate
pain, they are not fully effective and animals can still feel some discomfort or even pain
(Prunier
et al.,
2006; Von Borell
et al.,
2009). In addition, other husbandry procedures are
usually performed without any treatment for pain relief (Fredriksen
et al.,
2009). Since
these aversive experiences are paired with the presence of human, they can contribute
to develop fearfulness of pigs towards humans. This is of special importance for female
piglets that are reared for reproduction and are submitted to the same practices as other
piglets. To our knowledge, there has been no attempt to measure the long terms effect of
those painful handlings of newborn piglets.
12.2.2
Impact of non-painful interactions on suckling piglets
In addition to the influence of husbandry practices, the quality of human contacts during
routine activities (cleaning, feeding, animals' inspection) may influence the behaviour
of the piglets on a short and long term basis. For example, suckling piglets submitted
regularly to negative human interactions (speaking with aggressive tone, moving piglets,
demonstrating postural threats) expressed, on the day of weaning, more avoidance
reactions towards the person that performed the handling, than piglets submitted to
neutral interactions (little attention to the sow and piglets, soft tone of voice) (Sommavilla
et al.,
2011). However, when piglets were observed in the presence of an unknown
person, there was no difference in avoidance reaction between the two groups. In the
days following weaning, piglets that were subjected to the aversive human interactions
were more aggressive and rested less frequently compared with piglets that had received
neutral interactions. However, there was no difference in growth rate and feed intake
between the two groups.
There have been very few attempts to measure the long terms effect of those negative ways
of handling piglets. However, some data showed that fear of humans in an early age may
have negative consequences on later reproduction. Indeed, sows that expressed a high
fear of humans at 8 wks of age had lower reproduction success than those that were less
fearful at the same age (Janczak
et al.,
2003). In this experiment, the authors reported
that most of the animals' interactions with humans were negative (rough handling) from
birth. This suggests that early experience may have long term consequences.
Human handling may also be positive, but studies on the influence of positive handling
of piglets are rare. To our knowledge, only Hemsworth and his collaborators worked on
this topic. This may be due to the difficulty to handle very young animals, and to the
possible interference due to the presence of their mother. However, the first days/weeks
of postnatal life are known to be a sensitive period that favours the development of social
