Directory UMM :Data Elmu:jurnal:A:Applied Animal Behaviour Science:Vol70.Issue1.Nov2000:
Applied Animal Behaviour Science 70 (2000) 41±48
Relationships between individual behavioural
traits and post-weaning growth in segregated
early-weaned piglets
Sylvie Girouxa, Guy-Pierre Martineaua, Suzanne Robertb,*
a
College of Veterinary Medicine, University of Montreal, P.O. Box 5000, St-Hyacinthe, Que., Canada J2S 7C6
b
Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Route 108E,
P.O. Box 90, Lennoxville, Que., Canada J1M 1Z3
Accepted 12 April 2000
Abstract
Piglets' individual behavioural traits have been studied in the last decade but no report has linked
these traits with growth. This experiment was conducted to determine if behavioural traits of
segregated early-weaned piglets could be good predictors of their post-weaning growth and, thus,
help to predict their adaptation to early weaning. Following segregated early weaning at 171 days
old, 252 piglets were submitted to three tests between 20 and 25 days of age: open-®eld, reaction to
humans and rank order based on competition for a restricted-access feeder. The body weight of each
piglet was measured the day before weaning and once a week for the next 4 weeks. A principal
component analysis yielded ®ve factors with an Eigenvalue higher than 0.90 that accounted for 81%
of the total variation between individuals: reaction to humans (25%), active response to stress
(21%), passive response to stress (14%), feeding behaviour (10%) and rank order (9%). Passive
reaction to stress was associated with better weight gain during the ®rst week post-weaning
(r0.18; P0.01), and a positive correlation was found between social status and weight gain
during the 4 weeks following weaning (ÿ0.15rÿ0.10); P0.10). No relation was found
between reaction to humans and growth. These results con®rm the relationship between rank order
and growth in pigs and may suggest that reacting passively to stress could facilitate adaptation to
weaning. Crown Copyright # 2000 Published by Elsevier Science B.V. All rights reserved.
Keywords: Pig; Ontogeny; Weaning; Social behaviour; Segregated early weaning; Temperament test
*
Corresponding author. Tel.: 1-819-565-9174/219; fax: 1-819-564-5507.
E-mail address: roberts@em.agr.ca (S. Robert).
0168-1591/00/$ ± see front matter Crown Copyright # 2000 Published by Elsevier Science B.V. All rights reserved.
PII: S 0 1 6 8 - 1 5 9 1 ( 0 0 ) 0 0 1 4 0 - 4
42
S. Giroux et al. / Applied Animal Behaviour Science 70 (2000) 41±48
1. Introduction
Individual differences among behavioural traits of animals are of increasing interest in
the behavioural sciences. There could be enormous bene®ts for swine industry and pigs'
welfare if behavioural traits could be good predictors of adaptation to weaning and other
challenges (Spoolder et al., 1996). This could be particularly interesting in segregated early
weaning (SEW) herds where weaning is associated with sudden, important changes to
which some very young animals are unable to adapt (Robert et al., 1999). In the early
weaning context, a high level of exploration of the surroundings could accelerate discovery
of the surroundings and, thus, reduce the delay in feeding (Gonyou et al., 1998) and favour
growth. As many SEW producers feed their piglets up to six times per day during the ®rst
days after weaning, a favourable reaction to humans would also insure against behavioural
and physiological reactions to fear (Hemsworth and Barnett, 1987).
Some authors have attempted to identify pigs' individual characteristics. Hessing et al.
(1993a) reported evidence for an active/passive coping strategy differentiating aggressive
and non-aggressive piglets. They characterised the two types of piglets in function of their
behavioural responses, cortisol levels and heart rates in open-®eld test (Hessing et al.,
1993b). However, this classi®cation was criticised by other authors (Forkman et al., 1995;
Jensen et al., 1995a) who instead suggested three personality traits (aggression, sociability
and exploration) that explained 60% of the total variation among piglets.
The objective of the present study was to identify the behavioural characteristics of a
large group of early-weaned piglets and to determine if these traits could be good predictors
of their post-weaning growth and, thus, help to predict their adaptation to early weaning.
2. Materials and methods
2.1. Animals and husbandry
The study involved two replications of 16 crossbred litters born from purebred
(Yorkshire) and F1 (YorkshireLandrace) sows and boars of Duroc breed. The animals
were housed on a commercial farm in Que., Canada. On the day of birth, all piglets were
identi®ed by placing a numbered tag on their right ear. They received 2 ml of iron, the tails
of the female piglets were cut and the eye±teeth of all piglets were clipped. By Day 3 of the
experiment, the male piglets were castrated and their tails were cut. Within each
replication, only litters born
Relationships between individual behavioural
traits and post-weaning growth in segregated
early-weaned piglets
Sylvie Girouxa, Guy-Pierre Martineaua, Suzanne Robertb,*
a
College of Veterinary Medicine, University of Montreal, P.O. Box 5000, St-Hyacinthe, Que., Canada J2S 7C6
b
Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Route 108E,
P.O. Box 90, Lennoxville, Que., Canada J1M 1Z3
Accepted 12 April 2000
Abstract
Piglets' individual behavioural traits have been studied in the last decade but no report has linked
these traits with growth. This experiment was conducted to determine if behavioural traits of
segregated early-weaned piglets could be good predictors of their post-weaning growth and, thus,
help to predict their adaptation to early weaning. Following segregated early weaning at 171 days
old, 252 piglets were submitted to three tests between 20 and 25 days of age: open-®eld, reaction to
humans and rank order based on competition for a restricted-access feeder. The body weight of each
piglet was measured the day before weaning and once a week for the next 4 weeks. A principal
component analysis yielded ®ve factors with an Eigenvalue higher than 0.90 that accounted for 81%
of the total variation between individuals: reaction to humans (25%), active response to stress
(21%), passive response to stress (14%), feeding behaviour (10%) and rank order (9%). Passive
reaction to stress was associated with better weight gain during the ®rst week post-weaning
(r0.18; P0.01), and a positive correlation was found between social status and weight gain
during the 4 weeks following weaning (ÿ0.15rÿ0.10); P0.10). No relation was found
between reaction to humans and growth. These results con®rm the relationship between rank order
and growth in pigs and may suggest that reacting passively to stress could facilitate adaptation to
weaning. Crown Copyright # 2000 Published by Elsevier Science B.V. All rights reserved.
Keywords: Pig; Ontogeny; Weaning; Social behaviour; Segregated early weaning; Temperament test
*
Corresponding author. Tel.: 1-819-565-9174/219; fax: 1-819-564-5507.
E-mail address: roberts@em.agr.ca (S. Robert).
0168-1591/00/$ ± see front matter Crown Copyright # 2000 Published by Elsevier Science B.V. All rights reserved.
PII: S 0 1 6 8 - 1 5 9 1 ( 0 0 ) 0 0 1 4 0 - 4
42
S. Giroux et al. / Applied Animal Behaviour Science 70 (2000) 41±48
1. Introduction
Individual differences among behavioural traits of animals are of increasing interest in
the behavioural sciences. There could be enormous bene®ts for swine industry and pigs'
welfare if behavioural traits could be good predictors of adaptation to weaning and other
challenges (Spoolder et al., 1996). This could be particularly interesting in segregated early
weaning (SEW) herds where weaning is associated with sudden, important changes to
which some very young animals are unable to adapt (Robert et al., 1999). In the early
weaning context, a high level of exploration of the surroundings could accelerate discovery
of the surroundings and, thus, reduce the delay in feeding (Gonyou et al., 1998) and favour
growth. As many SEW producers feed their piglets up to six times per day during the ®rst
days after weaning, a favourable reaction to humans would also insure against behavioural
and physiological reactions to fear (Hemsworth and Barnett, 1987).
Some authors have attempted to identify pigs' individual characteristics. Hessing et al.
(1993a) reported evidence for an active/passive coping strategy differentiating aggressive
and non-aggressive piglets. They characterised the two types of piglets in function of their
behavioural responses, cortisol levels and heart rates in open-®eld test (Hessing et al.,
1993b). However, this classi®cation was criticised by other authors (Forkman et al., 1995;
Jensen et al., 1995a) who instead suggested three personality traits (aggression, sociability
and exploration) that explained 60% of the total variation among piglets.
The objective of the present study was to identify the behavioural characteristics of a
large group of early-weaned piglets and to determine if these traits could be good predictors
of their post-weaning growth and, thus, help to predict their adaptation to early weaning.
2. Materials and methods
2.1. Animals and husbandry
The study involved two replications of 16 crossbred litters born from purebred
(Yorkshire) and F1 (YorkshireLandrace) sows and boars of Duroc breed. The animals
were housed on a commercial farm in Que., Canada. On the day of birth, all piglets were
identi®ed by placing a numbered tag on their right ear. They received 2 ml of iron, the tails
of the female piglets were cut and the eye±teeth of all piglets were clipped. By Day 3 of the
experiment, the male piglets were castrated and their tails were cut. Within each
replication, only litters born