Social behavior
ANS 305
My lecture
 Will discuss some basic information on
aspects of social behavior
 Will present some results from our work
looking at the impact of feeder design on
some aspects of social behavior
Origins of Social Behavior
(Broom, 1981)
 Approach and join groups because
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they have probably found food
Predator approaches, get in the
middle of the group
Stay in group because early
warning by others can be used
Food depleted, one individual
leaves, follow it for it may know
where to find more food
Parental care increases survival
chances of offspring
Individual recognition
 Social stability
 Parent and offspring interactions
 Avoid inbreeding
 Mate choice
 Major histocompatibility complex (MHC)
– Maximizing diversity in immunological
responsiveness
Olfactory communication
 Pheromones
– Flehmen
 Urine marking
– territory
– own body
 Anal gland secretion
 Sebaceous skin glands
 Saliva
Stable Social Structures
 Communication
•
•
•
•
Vocalization
Visual display
Physical contact
Chemical communication
Stable Social Structures
 Reduced aggression
– Display
• Threat behavior
• Submissive behavior
Social organization
 Dogs may occupy and
defend a territory. Males,
females and juvenile have
distinct social order
Lorenz, 1953
Social organization
Social organization
 Cats spend most of time “alone”. Females may
defend a territory.
Leyhausen, 1982
Stable Social Structures
 Social recognition
• Optimal group size
– Sub groups may be formed
• Memory of social encounters
– Visual
– Olfactory
– Combination
Some terms used to describe
“social behavior”
 Social facilitation
 Social order
– Size
– Presence of weapons
– Territoriality
– Temperament
– Alliances
– Sex
• e.g. teat order in piglets
Social Organization (Fraser & Broom, 1990)
 Physical Structure of the territory
(=enclosure)
 Social Structure
 Group Cohesion (kinship; alliances)
Social organization
 Social strategies
1
1
2
2
3
4
5
4
3
5
6
Social organization
 Social strategies
1
1
2
HS
3
4
5
2 3
4 5
6
7
6
7 to 31
NS
32 33 34 35 36 37
LS
Social organization
 Sows were divided
into three groups:
– HS= High success in
agonistic interactions
– LS= Low success in
agonistic interactions
– NS= Now success in
agonistic interactions
1
2
HS
3
4
5
6
7 to 31
NS
32 33 34 35 36 37
LS
Social organization
 In natural settings, female pigs live in
groups of 4-6 (related animals) and their
offspring. Males may form a temporary
bond with the “family unit” (Mauget, 1985;
Wood-Gush and Stolba).
– Olfactory and visual signaling are important in
maintaining social stability
Challenges
 The majority of pregnant sows are kept in
gestating crates
• High levels of unresolved aggressive interactions
may occur (Broom, Mendl & Zanella, 1996)
 The concentration of environmental
contaminants (e.g. ammonia) may interfere
with olfactory memory (Mendl personal
communication)
Challenges..
 Maternal deprivation stress, at an early age,
may alter social memory (Yuan et al. 1999)
Social organization
 Stallions related to a group of mares in a
very stable way (harem). Non-breeding
males may form bachelor groups.
• Testosterone levels are, oftentimes, below the level
of detection in stallions living in a “bachelor” group.
Acceptance into a group of mares is related to an
instantaneous rise in testosterone and changes in
behavior (McDonnell, 1997).
 Stallions are not territorial.
Challenges
 In some commercial farms horses are
housed in individual stalls, with restrict
social contact
 Housing stallions in close proximity may
cause a decrease in reproductive
performance
Social Organization
 Male donkeys may defend a territory and try to
attract females
– Vocalizations (primarily)
– Male donkeys are territorial
Social Organization
 Female grouping is observed in sheep, goats &
cattle. During non-breeding season males may
form “bachelor” groups. Social grooming is an
important feature of cattle social behavior
Social organization
 Hens and cocks have separate “peck orders”. They
are territorial.
– Social unit: dominant cock, 4 to 6 hens, pullets and
several subordinate males
Large Round Bale Feeder Design
Affects the Occurrence of Aggressive
Interactions in Beef Cows
L.M. Korzun, D. D. Buskirk, T. M. Harrigan,
D. R. Hawkins, and A. J. Zanella
Michigan State University
The Problem
 Feed is the greatest expense for wintering
beef cattle in Michigan
– estimated $377.99/cow with $100/cow forage costs
(MSU-IRM-SPA 1998)
 Majority of hay is fed in large round bales
(Michigan Beef Cow Calf Survey- MSU AES 1991)
 Observations suggest a difference in hay
wastage between different feeder designs
Hypothesis
 Round bale feeder design affects social and
feeding behavior of cattle.
Objective
 To examine the impact of round bale feeder
design on the behavior of cattle
Methods
 80 non-lactating beef cows separated by
weight and weight range into 4- 19.5m x
18m pens
 Each pen contained one of 4 feeders placed
under video surveillance cameras
– feeders were rotated after day 7
 Ad libitum hay offered, refused hay from
each feeder collected and weighed daily
Methods- Feeder Types
Ring
Cone
Cradle
Trailer
Methods- Behavioral Sampling
 Data collected in 5 minute samples
• 8am-5pm, 30 minute intervals
 Check sheet:
• continuous observation for frequencies
• instantaneous sampling for cattle numbers
 190 segments total were decoded for behaviors
• frequency of aggressive interactions
• transitions in/out of feeder
 data analyzed using the SAS program
Definitions
 Aggression - animal
threatens or attempts to
remove another animal
from the feeder or vicinity
 In feeder - animal places
head in designated slat of
feeder
 Out of feeder - animal
removes head from
designated slat in feeder
Results
Aggressive Interactions vs Feeder Design
1.8
Aggressive interactions per 5 minutes
observation (LSMEAN + SE)
1.6
a
Different superscripts have P<0.01
1.4
ab
1.2
1
c
bc
Ring
Cone
0.8
0.6
0.4
0.2
0
Cradle
Trailer
Feeder Design
Results
a
Transitions vs Feeder Design
ab
Different Superscripts have P< 0.05
Transitions per 5 Minutes Observation
(LSMEAN + Std Error)
2
b
1.8
1.6
1.4
c
c
1.2
1
0.8
0.6
0.4
0.2
0
Cradle
Trailer
Ring
Feeder Design
Cone
Results
Hay Wastage vs Feeder Design
16
Hay Wastage (% DM)
14
12
10
8
6
4
2
0
Cradle
Trailer
Ring
Feeder Design
Cone
Conclusions
 Round bale feeder design has an impact on
cattle behavior.
 Cows feeding from Trailer and Cradle feeders
showed a greater number of aggressive
interactions than cows fed at round feeders.
 Cows feeding from Trailer and Cradle feeders
had a higher frequency of transitions in/out of
feeder than cows fed at round feeders.
Discussion
 Why is difference in behavior related to feeder
design?
– Animal vulnerability
– Body contact and opportunity to escape
– Feeding height
 Can we use behavior to design a better feeder?
 More research to come...