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 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

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Social strategies

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5

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Social organization Social strategies

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7 to 31

HS

LS

NS

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

32 33 34 35 36 37

12

34

56

7 to 31

HS

LS

NS

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

Round bale feeder design affects social and feeding behavior of cattle.

Hypothesis

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

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0.2

0.4

0.6

0.8

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1.2

1.4

1.6

1.8

Cradle Trailer Ring Cone

Feeder Design

Aggressive interactions per 5 minutes

observation (LSMEAN

+ SE)

Different superscripts have P<0.01

ab

a

c bc

Results

c

Transitions vs Feeder Design

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0.2

0.4

0.6

0.8

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1.2

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Cradle Trailer Ring Cone

Feeder Design

Transitions per 5 Minutes Observation

(LSMEAN

+ Std Error)

Different Superscripts have P< 0.05

a

ab

b

c

Results

Hay Wastage vs Feeder Design

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Cradle Trailer Ring Cone

Feeder Design

Hay Wastage (% DM)

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...