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At least 19 recordsLinked to original sources
PubMed1986

Agonistic behavior in food animals: review of research and techniques.

One type of social behavior--agonistic behavior--is commonly observed among food animals. Agonistic behaviors are those behaviors which cause, threaten to cause or seek to reduce physical damage. Agonistic behavior is comprised of threats, aggression and submission. While any one of these divisions of agonistic behavior may be observed alone, they usually are found, in sequence, from the start to the end of an interaction. Food animals may show interspecific or intraspecific agonistic behaviors. Interspecific agonistic behavior has not been extensively studied but it is agriculturally important because farm workers may become injured or killed by aggressive food animals. Types of intraspecific agonistic behavior are: when animals are brought together, intermale fighting, resource defense, inter-gender fighting and aberrant aggression. Common pitfalls in research on agonistic behavior among food animals include too few replicates to detect a biological difference, the assumptions of the analysis are not met, only aggression and not submission or other agonistic behavior components are measured, incomplete description of the behaviors are reported and a complete, quantitive ethogram did not form the basis for selecting behavioral measures.

Aggression↗
PubMed1987

Psychotropic effects of adrenergic beta-blockers on agonistic behavior between resident and intruder mice.

The present study was conducted to investigate the effect of adrenergic beta-blockers on agonistic behavior in male mice, using quantitative ethological methods. Agonistic behavior was evoked using a resident-intruder paradigm. The following drugs were administered orally at four dose levels (vehicle, 5, 10 and 20 mg/kg) to either resident or intruder mice: dl-propranolol, practolol, d-propranolol, and l-propranolol. When the resident was treated with either dl-propranolol or l-propranolol, aggressive episodes (offensive sideways posture, attack bite, tail rattle) were suppressed significantly in a dose-dependent manner, whereas practolol and d-propranolol were ineffective. All treatments except the high dose of l-propranolol failed to affect the resident's solitary behavior (locomotion). When the intruder was treated with beta-blockers, agonistic behavior was not altered. Since practolol does not cross the blood-brain barrier, the differential suppression of agonistic behavior is due to the central action of beta-blockers. d-Propranolol does cross the blood-brain barrier but is devoid of beta-receptor blocking property; hence l-propranolol suppression of agonistic behavior implies inactivation of brain adrenergic beta-receptors. The findings seem to indicate that beta-blockers such as dl-propranolol and l-propranolol have a psychotropic action.

Adrenergic beta-Antagonists↗
PubMed1975

Theoretical review: a model of hormones and agonistic behavior.

A model of the interaction between endocrine function and agonistic responding was developed that incorporates three specific hypotheses about the relationship between hormones and agonistic behavior: (1) The baseline hormonal state of the organism contributes to the determination of whether, in what way, and how intensely the animal will react when it is exposed to appropriate environmental stimuli. (2) One function of the hormonal responses to environmental stimulation and behavioral experiences is to modify the continuing and future behavior of the individual in the same or similar situations. (3) Another function of these hormonal responses is to modify the individual's stimulus qualities so that other individuals' agonistic reactions to it will be modified. The data on hormones and agonistic behavior were reviewed in the context of this model, and some directions for future research were proposed.

Adrenal Glands↗
PubMed1975

Agonistic behavior in the German cockroach, Blattella germanica.

Agonistic behavior in Blattella germanica is delineated with an emphasis on fighting techniques and population factors affecting aggressiveness. Male-male, male-female, and male-male encounters are not significantly different in either level of aggressiveness or frequency. Female-female carrying oothecae are, however, more aggressive than other female-female. The mean intensity of aggression increases as population density is increased, but number of contacts per individual per unit time remains constant. Defense of specific, territories does not occur and aggressive interactions are most common during the dark portion of the photocycle, when many of the cockroaches are observed to be foraging.

Aggression↗
PubMed1977

[Classical conditioning of agonistic behavior in the Syrian golden hamster (Mesocricetus auratus Waterhouse)].

Nine different reactions of unconditioned agonistic behavior of golden hamsters (Mesocricetus auratus Waterhouse) which could be elicited by an air blow (UCS) were classically conditioned at a sound of a xylophone (tone g), a previously neutral stimulus. Tone g (CS) was paired with UCS for a different number of trials/day. In all animals exposed to over 20 pairings/day components of the agonistic behavior were brought under the control of CS, but it was not possible to predict which one of the agonistic reactions would appear. Most of the animals generalized and also showed conditioned reactions (CR) when presenting tone c' instead of tone g. When utilizing a differential conditioning procedure the animals learned to discriminate between the different tones. Extinction of CR at tone g was reached after an individually different number of trials.

Acoustic Stimulation↗
PubMed1988

Reduction of pig agonistic behavior by androstenone.

One hundred twenty-four prepuberal crossbred pigs were used in a series of behavioral bioassays to determine the minimum dose of androstenone (5 alpha-androst-16-en-3-one) that would reduce the level of agonistic behavior among dyads of newly regrouped pigs. Randomly selected females and castrated males were used in 21-h videotaped observation periods. In Exp. 1, isopropyl alcohol was tested against no aerosol to determine if the vehicle (isopropyl alcohol) influenced agonistic behavior. Level of submissive and aggressive behaviors were similar (P greater than .10) between treatments. In Exp. 2, vehicle or androstenone in vehicle was sprayed on the snout and head of both pigs at the start of the encounter. Four bioassays were performed with four levels (.05, .5, 5 and 50 micrograms/pig) of androstenone dissolved in isopropyl alcohol. Sprayed isopropyl alcohol served as a control. At concentrations of .5 and 5 micrograms/pig, androstenone reduced aggressive behavior (P less than .05). Androstenone had no consistent effect on submissive behavior. In Exp. 3, androstenone was sprayed on pigs at the start of the encounter and again at 30, 60 and 90 min after pairs of pigs were mixed. Repeated application of this androgen resulted in levels of agonistic behavior similar to those recorded when nothing was applied (P greater than .10). A single application of as little as .5 micrograms androstenone per pig reduced aggressive behavior among prepuberal pigs and, therefore, may be a way of reducing fighting among newly regrouped prepuberal pigs.

Aerosols↗
PubMed1988

Psychotropic effects of ginseng saponins on agonistic behavior between resident and intruder mice.

The psychotropic actions of crude ginseng saponins, pure ginsenoside Rb1 (GS-Rb1) and ginsenoside Rg1 (GS-Rg1) obtained from the root of Panax ginseng, were evaluated from their effects on agonistic behavior in mice. A resident-intruder test situation was used. When the resident mouse was treated with crude ginseng saponins (25, 50 and 100 mg/kg i.p.), aggressive episodes (offensive sideways posture and attack bite) were significantly suppressed in a dose-dependent manner. However, the agonistic behavior was not altered when the intruder was treated with crude ginseng saponins. GS-Rb1 (2.5, 5 ad 10 mg/kg i.p.) also significantly suppressed aggressive episodes when given to the resident, whereas GS-Rg1 (2.5, 5 and 10 mg/kg i.p.) was ineffective. Neither GS-Rb1 nor GS-Rg1 given to the intruder caused any significant changes in the behavior of the resident. Although the highest dose of crude ginseng saponins suppressed locomotion frequency, it appears that both crude ginseng saponins and GS-Rb1 possess a specific psychotropic action on agonistic behavior.

Aggression↗
PubMed1992

[Comparison of the effects of benzodiazepine and non-benzodiazepine anxiolytics on agonistic behavior in male mice].

The present study investigated whether there is any difference between the effects of benzodiazepine and non-benzodiazepine anxiolytics on agonistic behavior in male mice, using an ethopharmacological technique. Agonistic behavior was evoked using a resident-intruder paradigm. The effects of four doses of the following drugs were assessed in either resident or intruder mice: diazepam (vehicle, 1, 2.5 and 5 mg/kg, p.o.) and tandospirone (vehicle, 2.5, 5 and 10 mg/kg, p.o.). Residents and intruders were drugged on alternate test days, and all animals received different sequences of each of the drug conditions according to a random schedule. The injection-test interval was 30 min. When a resident mice were treated with either diazepam or tandospirone, the frequency of attack bite was suppressed significantly in a dose-dependent manner. When intruder mice were treated with diazepam, attack bites by untreated residents were significantly increased, whereas tandospirone was ineffective. Although diazepam caused a significant decrease in both locomotion and rearing, tandospirone did not cause motor dysfunction. These evidence indicate that tandospirone, a 5-HT1A receptor agonist, has different pharmacological properties from diazepam.

Agonistic Behavior↗
PubMed1985

[Pharmaco-ethological analysis of agonistic behavior between resident and intruder mice: effects of adrenergic beta-blockers].

The present study was conducted to investigate the effects of adrenergic beta-blockers on agonistic behavior using quantitative ethological methods. In order to generate the agonistic behavior we employed the resident-intruder paradigm: An intruder male mouse is introduced into the home cage of a resident male mouse that has been cohabiting with a female for 5 weeks. The following drugs were administered orally to either resident or intruder mice: dl-Propranolol, oxprenolol, and carteolol. The injection-test interval was 60 min. Each test was recorded using a video TV monitor system, and at a later time several behavioral elements shown by both resident and intruder mice were measured. dl-Propranolol (5, 10, 20 mg/kg), oxprenolol (30, 50, 75 mg/kg), and carteolol (30, 50, 75 mg/kg) significantly suppressed the resident's aggressive episodes (offensive sideways posture, tail rattle, and attack bite) when resident mice were treated. By contrast, when intruder mice were treated with beta-blockers, aggressive episodes by untreated residents were not affected. The results suggest that dl-propranolol, oxprenolol, and carteolol have specific effects on the hostility of resident mice.

Administration, Oral↗
PubMed1990

The effects of depo-medroxyprogesterone acetate (DMPA) on copulation-related and agonistic behaviors in an island colony of stumptail macaques (Macaca arctoides).

This study examined the effects on copulation-related and agonistic behaviors of repeated DMPA (depo-Provera) treatment of adult females in a heterosexual island colony of stumptail macaques (Macaca arctoides). Comparison of mean rates revealed a decrease in male approach to females and dominant male following of females after they were treated with DMPA. As treatment did not affect female genital present, female approach or follow of males, we conclude, consistent with earlier results, that DMPA primarily reduced female sexual attractiveness. DMPA treatment was also consistently associated with increased female agonistic behavior (i.e., low-level threat, bite, and fear grimace), with aggression directed primarily at subadults, juveniles, and infants. Treatment did not alter dominance relationships. These data suggest that DMPA treatment is associated with increased low-key contact aggression.

Aggression↗
PubMed1987

Effects of heat and social stressors and within-pen weight variation on young pig performance and agonistic behavior.

A total of 486 crossbred weanling pigs was used in a series of experiments to determine first the effects of heat and social stress and their interaction on pig performance and, second, to determine a possible cause for the observed effects. Pigs were held six/nursery pen and fed and watered ad libitum. In Exp. 1, pigs were held at either thermal neutral 26.6 C for the 21 d and 23.8 C for the final 7 d, or at the heat-stress temperature (32.2 C) for the entire 28-d period. Within each temperature treatment, one-half of the pigs were left as single-litter controls and one-half were randomly regrouped (social stress). Pig feed intake and weight gain were reduced (P less than .05) among heat-stress pigs during the 7- to 28-d and 0- to 28-d periods. The interaction between social and thermal stress was significant for gain:feed ratio for the 7- to 28- and 0- to 28-d periods. Regrouping depressed gain:feed ratio only among heat-stressed pigs. In Exp. 2, a two-pig behavioral bioassay was used to determine if agonistic behaviors were influenced by heat stress. Pigs that were regrouped into 32.2 C rooms exhibited reduced mean level (P less than .05) and variation (P less than .001) of submissive behavior. Duration of aggressive behavior and latency to attack were unaffected by thermal treatments. Increased social stress at the time of regrouping could not account for poor performance of heat-stressed, regrouped pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aggression↗
PubMed1979

The effects of alcohol on agonistic behavior in the Telomian dog.

The study analyzed the effects of alcohol on agonistic behavior in three independent social systems, each compromised of two male and one female Telomian dog. Three dose levels were used: 0, 0.8, and 1.6 g/kg body weight of absolute alcohol diluted to 20%. Observations were made when none, one (top, middle or low ranking), or all dogs in a system received a given treatment. At the 0.8 g/kg level, low ranking dogs showed an increased frequency of attacks and bone possession time, while top and middle ranking dogs showed a decrease. At the 1.6 g/kg level, all subjects decreased their attacks and bone possession time. Alcohol decreased frequency of agonistic vocalizations under all conditions. There were differential social rank effects on frequency of retreats. Overall, the results were similar whether one or all dogs received the particular treatment.

Aggression↗
PubMed1977

Long term reduction of male agonistic behavior in mice following early exposure to ethanol.

A system was developed to study the ability of early (pre- and neonatal) ethanol input to induce long lasting neural and behavioral changes. Ethanol was administered to E7b1/10bg and DBA/1Bg offspring through their parents who received 10% ethanol as their only liquid supply either before and during pregnancy, or from delivery until 14 days post partum, or during both periods. Thus, the offspring received ethanol transplacentally and/or through the mother's milk. The present paper is concerned with the male agonistic behavior at age 50 days of the treated offspring as compared with their pair fed controls. Early ethanol input resulted in a 23% increase in latency to attack in C57 mice and 58% in DBA, as well as a 49% (C57) and 38% (DBA) decrease in time spent fighting. The sensitive period to ethanol effect was apparently postnatal. Prenatal administration had no effect on agonistic behavior. DBA offspring were more aggressive than C57 and the scores of C57 offspring were more variable, thus indicating a lower phenotypic buffering in this strain.

Aggression↗
PubMed1978

Agonistic behavior elicited by electrical stimulation of the brain in western collared lizards, Crotaphytus collaris.

Western collared lizards, Crotaphytus collaris, were tested in three experiments using electrical stimulation of the brain. In experiment 1, agonistic behavior (defensive, aggressive and escape) responses were elicited in free-moving unanesthetized lizards. In experiment 2, areas were localized from which gular extension, a common component of defensive and aggressive behavior, could be evoked in anesthetized animals. Experiment 3 was carried out to demonstrate that defensive and aggressive behavior could be elicited from the same stimulation sites both in anesthetized and unanesthetized lizards. Initially, gular extension was evoked while the animal was anesthetized and later the animal was tested while freely moving and unanesthetized. Based on a combined plot of the sites from which defensive and aggressive behavior was evoked in experiments 1--3, the higher threshold sites (51--750 muA) were in the dorsal ventricular ridge anterior, amygdaloid complex, septal and preoptic areas, hypothalamus, thalamus and adjacent to the nucleus profundus mesencephali (NPM) and reticular formation. Lower threshold sites (up to 50 muA) are found in the NPM and the reticular formation. Escape behavior can be evoked from stimulation sites within or adjacent to areas from which defensive and aggressive behavior can be elicited.

Aggression↗
PubMed1989

Influence of the mesocortical dopaminergic system on activity, food hoarding, social-agonistic behavior, and spatial delayed alternation in male rats.

In order to assess the behavioral role of the dopaminergic mesocortical input to the prefrontal cortex, bilateral lesions were made in the ventral tegmental area (VTA). The possibility of a functional recovery by the administration of a dopamine agonist was examined. General activity, food hoarding, social-agonistic behavior, and spatial delayed alternation performance were recorded in rats with VTA lesions and in sham-operated animals. In the open field animals with VTA lesions were more active but showed less anxiety. Food hoarding was impaired. In dyadic interactions with sham-operated opponents, VTA rats were socially more active, whereas sham operates performed more keeping down and aggressive grooming. This behavioral deficit was partially recovered when apomorphine was administered prior to testing. VTA animals were impaired in the performance of a spatial delayed alternation task with an intertrial interval of 15 s, whereas no impairment was found with a 0-s intertrial interval. The theoretical implications of these findings are discussed.

Aggression↗
PubMed1977

5,7-Dihydroxytryptamine lesions of the ascending 5-hydroxytryptamine pathways: habituation, motor activity and agonistic behavior.

Rats were injected stereotactically in mesencephalon with 5,7-dihydroxytryptamine (5,7-DHT) in the medial 5-hydroxytryptamine (5-HT) pathway (n = 8) and in the medial plus the lateral 5-HT pathways (n = 7) or injected with vehicle (n = 8), or sham-operated (n = 8). The 5,7-DHT lesions reduced the in vitro 3H-5-HT uptake in the hypothalamus and the cortex cerebri to 27-51% of control values, 3H-noradrenaline uptake was not significantly changed. 5,7-DHT lesions of the medial, and of the medial plus the lateral, 5-HT induced mouse killing behavior and increased number of boxing positions in the shock elicited fighting test. Both lesions also reduced the rate of habituation to touch, but only the lesion of the medial plus the lateral 5-HT pathway significantly reduced the rate of habituation to acoustic stimulation. Activity in the home cage was not significantly changed by the lesions. It was concluded that selective chemical lesions of the ascending 5-HT pathways result in prolonged habituation of the orienting response and increase in particular components of agonistic behavior. The increase in locomotor activity observed after electrolytic lesions of nucleus raphe medianus seems not to be due only to lesion of the 5-HT neurons ascending from this nucleus.

5,7-Dihydroxytryptamine↗
PubMed1988

Effects of photoperiod, the pineal gland and the gonads on agonistic behavior in female golden hamsters (Mesocricetus auratus).

Four studies were conducted to determine the role of photoperiod, the pineal gland and the gonads in the regulation of intrasex agonistic behavior in female hamsters. In the first experiment animals maintained under Long or Short photoperiods were tested in same or opposite photoperiod pairs. Under both testing conditions, Short-day animals tended to exhibit a higher ratio of offensive to defensive behaviors, which was due primarily to a reduced level of defensive behavior in Short-day groups. In the second experiment animals under Long and Short photoperiods were tested following sham surgery or pinealectomy. Short-day sham animals exhibited the highest level of offensive behavior, the lowest level of defensive behaviors and the highest offensive/defensive ratio; pinealectomy eliminated the Short-day advantage. In the third experiment, Long-day animals receiving exogenous melatonin showed a higher level of agonistic responding than animals injected with control vehicle, indicating that Short-day effects are probably mediated through pineal melatonin. The results of the last experiment in which ovariectomy to Long-day animals was not able to mimic the effects of photoperiod or exogenous melatonin indicated that the photoperiod effects on aggression are probably not mediated through the gonads.

Aggression↗