370 likes | 760 Views
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).
E N D
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 • 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 3 4 5 5 6
Social organization • Social strategies 1 HS 2 3 1 4 5 6 2 3 4 5 6 7 LS 7 to 31 32 33 34 35 36 37 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
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
Cone Ring Trailer Cradle Methods- Feeder Types
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 a ab Different Superscripts have P< 0.05 b c c
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...