Environmental and genetic factors influencing the development of belly nosing in the early-weaned pig
Date
2005
Authors
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Journal ISSN
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Publisher
ORCID
Type
Degree Level
Doctoral
Abstract
This study investigated environmental and genetic factors influencing the
development of belly nosing in the early-weaned pig. The first experiment investigated
the effects of gender, duration of liquid milk replacer supplementation, breed line and
environmental enrichment designed to simulate components of a sow's udder, on the
incidence of belly nosing and its associated behaviours in pigs weaned at 7 days-of-age.
Both breed line and environmental enrichment were found to affect the incidence of oralnasal
behavioural vices related to belly nosing. Differences between breed lines were
found in the types of behavioural vices performed and whether these vices were generally
focused or directed at specific regions of the body of penmates. Enrichment devices,
designed for nosing, rooting, sucking, and biting were also found to be specific in the
types of behavioural vices they effectively alleviated. Significant breed line by
environmental enrichment interactions were found, with Yorkshire pigs more responsive
to environmental enrichment than Duroc pigs.
The second study documented the ontogeny of belly nosing from weaning into the
grow-finish period in pigs weaned at 12-14 days-of-age and determined whether early
belly nosing correlated with behavioural vices observed during the grow-finish period.
The results of the study suggest that after belly nosing subsides, a number of other oralnasal
behaviours take its place. Pigs that progressed from belly nosing to belly sucking,
tended to continue to perform belly sucking behaviour into the grow-finish phase. In
contrast, piglets which exhibited generalized nosing and sucking behaviours during the
grow-finish period were more likely to tail bite and to engage in generalized biting of
penmates. A direct correlation between belly nosing during the nursery phase and tail
biting during the grow-finish period was not found.
The third study investigated the effects of sire breed and individual sires within
breed on belly nosing. Breed of sire affected whether nosing and sucking behaviours
were generally focused or directed towards the belly of penmates. Specifically, Large
White-sired pigs performed more belly nosing and belly sucking behaviour, while Duroc-sired
pigs performed more generally directed nosing and sucking behaviours.
The fourth study investigated the use of 'relevant' environmental enrichment
devices to further clarify the underlying motivation for belly nosing. A second objective
was to investigate the provision of such enrichment at two different developmental stages
to determine whether a sensitive period exists for the introduction of environmental
enrichment. While providing any type of environmental enrichment during the nursery
phase reduced belly nosing, providing nosing enrichment in particular had the most
significant effect, despite it being the least utilized. The sensitive period for providing
environmental enrichment to reduce belly nosing was found to be during the early
nursery phase, within the first two weeks following weaning.
The final study investigated the thermal preference of early-weaned pigs as it
relates to activity levels, huddling and belly nosing. Early-weaned pigs preferred cooler
temperatures during the night, when they huddled to keep warm, and warmer
temperatures during the day. Activity levels and belly nosing also demonstrated a diurnal
pattern, with the highest incidence of belly nosing occurring during the transition from
piglets being more active during the day to spending more time lying at night.
Belly nosing is influenced by both environmental and genetic factors.
Recognizing the circumstances in which belly nosing occurs will help in designing
strategies to reduce the incidence of the behaviour, while still keeping the practice of
early weaning as a viable option in disease eradication programs.
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Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
Animal and Poultry Science
Program
Animal and Poultry Science