Social behavior ANS 305

My lecture 4 Will discuss some basic information on aspects of social behavior 4 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) 4 Approach and join groups because they have probably found food 4 Predator approaches, get in the middle of the group 4 Stay in group because early warning by others can be used 4 Food depleted, one individual leaves, follow it for it may know where to find more food 4 Parental care increases survival chances of offspring

Individual recognition 4 Social stability 4 Parent and offspring interactions 4 Avoid inbreeding 4 Mate choice 4 Major histocompatibility complex (MHC) –Maximizing diversity in immunological responsiveness

Olfactory communication 4 Pheromones –Flehmen 4 Urine marking –territory –own body 4 Anal gland secretion 4 Sebaceous skin glands 4 Saliva

Stable Social Structures 4 Communication Vocalization Visual display Physical contact Chemical communication

Stable Social Structures 4 Reduced aggression –Display Threat behavior Submissive behavior

Social organization 4 Dogs may occupy and defend a territory. Males, females and juvenile have distinct social order Lorenz, 1953

Social organization

4 Cats spend most of time “alone”. Females may defend a territory. Leyhausen, 1982

Stable Social Structures 4 Social recognition Optimal group size –Sub groups may be formed Memory of social encounters –Visual –Olfactory –Combination

Some terms used to describe “social behavior” 4 Social facilitation Social facilitation 4 Social order –Size –Presence of weapons –Territoriality –Temperament –Alliances –Sex e.g. teat order in piglets

Social Organization (Fraser & Broom, 1990) 4 Physical Structure of the territory (=enclosure) 4 Social Structure 4 Group Cohesion (kinship; alliances)

Social organization Social strategies

Social organization 4 Social strategies to 31 HS LS NS

Social organization 4 Sows were divided into three groups: Sows were divided into three groups –HS= High success in agonistic interactions –LS= Low success in agonistic interactions –NS= Now success in agonistic interactions

Social organization 4 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 4 The majority of pregnant sows are kept in gestating crates High levels of unresolved aggressive interactions may occur (Broom, Mendl & Zanella, 1996) 4 The concentration of environmental contaminants (e.g. ammonia) may interfere with olfactory memory (Mendl personal communication)

Challenges.. 4 Maternal deprivation stress, at an early age, may alter social memory (Yuan et al. 1999)

Social organization 4 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). 4 Stallions are not territorial.

Challenges 4 In some commercial farms horses are housed in individual stalls, with restrict social contact 4 Housing stallions in close proximity may cause a decrease in reproductive performance

Social Organization 4 Male donkeys may defend a territory and try to attract females –Vocalizations (primarily) –Male donkeys are territorial

Social Organization 4 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 4 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 4 Feed is the greatest expense for wintering beef cattle in Michigan –estimated $377.99/cow with $100/cow forage costs (MSU-IRM-SPA 1998) 4 Majority of hay is fed in large round bales (Michigan Beef Cow Calf Survey- MSU AES 1991) 4 Observations suggest a difference in hay wastage between different feeder designs

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

Objective 4 To examine the impact of round bale feeder design on the behavior of cattle

Methods 4 80 non-lactating beef cows separated by weight and weight range into m x 18m pens 4 Each pen contained one of 4 feeders placed under video surveillance cameras –feeders were rotated after day 7 4 Ad libitum hay offered, refused hay from each feeder collected and weighed daily

Methods- Feeder Types Ring Cone Cradle Trailer

Methods- Behavioral Sampling 4 Data collected in 5 minute samples 8am-5pm, 30 minute intervals 4 Check sheet: continuous observation for frequencies instantaneous sampling for cattle numbers segments total were decoded for behaviors frequency of aggressive interactions transitions in/out of feeder 4 data analyzed using the SAS program

Definitions 4 Aggression - animal threatens or attempts to remove another animal from the feeder or vicinity 4 In feeder - animal places head in designated slat of feeder 4 Out of feeder - animal removes head from designated slat in feeder

Results

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Results

Conclusions 4 Round bale feeder design has an impact on cattle behavior. 4 Cows feeding from Trailer and Cradle feeders showed a greater number of aggressive interactions than cows fed at round feeders. 4 Cows feeding from Trailer and Cradle feeders had a higher frequency of transitions in/out of feeder than cows fed at round feeders.

Discussion 4 Why is difference in behavior related to feeder design? –Animal vulnerability –Body contact and opportunity to escape –Feeding height 4 Can we use behavior to design a better feeder? 4 More research to come...