Applied Animal Behaviour Science 148 (2013) 85–92
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Applied Animal Behaviour Science
jou rn al hom epage : w ww.elsevier.com/locate/applanim
Disrupting motivational sequences in chicks: Are there
affective consequences?
Birgitte Seehuus
a,∗
, Mike Mendl
b
, Linda J. Keeling
a
, Harry Blokhuis
a
a
Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Box 7068, SE 75007 Uppsala, Sweden
b
Animal Behaviour and Welfare, Husbandry, Langford House, Langford BS 40 5 DU, United Kingdom
a r t i c l e i n f o
Article history:
Accepted 26 July 2013
Available online 5 August 2013
Keywords:
Laying hen chicks
Cognitive bias
Motivational sequences
Feed reward cycle
Positive emotions
Affective states
a b s t r a c t
The ‘reward cycle’ conceptualises reward acquisition as a cyclic phenomenon divided into
three motivational stages with related emotional or affective states. For feeding behaviour
such a cycle consists of an appetitive stage characterised by foraging and exploration linked
to emotions such as wanting and anticipation, a consummatory stage with eating behaviour
linked to liking and pleasure, and a post-consummatory stage linked to satiety and relax-
ation with behaviour like resting and preening. In this study we investigated whether
disturbing the feed reward cycle in laying hen chicks, by denying access to parts of a pen
designed to accommodate the stages of the cycle (litter area ‘appetitive’; feed area ‘consum-
matory’; perches and dark area ‘post-consummatory’), resulted in a more negative affective
state. To test this, we used a spatial cognitive bias task in which a bowl in one location
in the test arena was associated with a positive outcome (mealworm), and in a different
location with a negative outcome (unpalatable puffed rice soaked in quinine sulphate).
Three ambiguous probe locations were presented during the test. Chicks (n = 22) discrimi-
nated between the positive and negative location as evidenced by a significant difference
in times to reach these locations (mean difference variable-feed treatment 22.1 ± 8.8 s;
closed-litter treatment 23.3 ± 6.5 s; closed-dark treatment 24.4 ± 4.9 s and baseline mean
difference 22.3 ± 6.4 s). Chicks denied access to the litter area was significantly quicker to
reach the probe near the negative location than when denied access to the feed area (mean
8.9 ± 1.7 vs. 18.6 ± 1.7) – an ‘optimistic’ judgement of ambiguity indicative of a less nega-
tive affective state when denied litter compared to when denied feed. Relative to the initial
baseline cognitive bias tests, all treatments resulted in slower times to reach the negative
location (closed-dark: 14.9 ± 1.9; variable-feed: 12.6 ± 1.9; closed-litter: 13.7 ± 1.9) and
shorter times to the positive location (closed-dark: -7.3 ± 1.7; variable-feed: -7.2 ± 1.7;
closed-litter: -7.3 ± 1.7). Continuing improvement in learning of the positive versus neg-
ative location discrimination following baseline tests, or a change in perception of the
incentive value of the positive and negative outcomes, may explain this finding. There was
no evidence that variations in fearfulness or sociality (measured in tonic immobility and
social reinstatement tests) affected the outcome of the cognitive bias tests. There seems
to be different reactions to disrupting different parts of a reward cycle and further inves-
tigations into the links between affect and motivational sequences may provide a better
understanding of the affective importance of different resources.
© 2013 Elsevier B.V. All rights reserved.
∗
Corresponding author. Tel.: +47 976 639 64; fax: +46 018 67 35 88.
E-mail address: Birgitte.Seehuus@slu.se (B. Seehuus).
0168-1591/$ – see front matter © 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.applanim.2013.07.008