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Malek, E. A. (1971). The life cycle of Gastrodiscus aegyptiacus (Cobbold, 1876) Looss, 1896 (Trematoda: Paramphistomatidae: Gastrodiscinae). J Parasitol, 57(5), 975–979.
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Cattell, R. B., & Korth, B. (1973). The isolation of temperament dimensions in dogs. Behav Biol, 9(1), 15–30.
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Flauger, B. (2011). The introduction of horses into new social groups with special regard to their stress level. Ph.D. thesis, , .
Abstract: Horses are a highly social species living in complex social systems which should require them to memorise and generalise social experiences and distinguish between familiar and unfamiliar conspecifics. In the main part of my thesis I concentrated on the specific conflict situation of a horse being introduced into a new social group, and investigated its behaviour and stress level. Horses were either introduced (1) immediately, (2) after an observation period, or (3) together with an integration horse after an observation period. Additionally, in the second part of my thesis I arranged several experiments to elaborate additional aspects which could affect the behaviour of horses during introductions. In this study I could describe a simplified method for measuring stress through the analysis of faecal GCMs in horses. An enzyme immunoassay (EIA) for 11-oxoaetiocholanolone using 11-oxoaetiocholanolone-17-CMO: BSA (3?,11-oxo-A EIA) as antigen showed high amounts of immunoreactive substances. The new assay increases the accuracy of the test and lowers the expenses per sample; also storing of samples at room temperature after collection is less critical. This is a big advantage both in the field of wildlife management of equids and in the field of equestrian sports (chapter 1). Comparing the different introduction techniques, the introduction with an integration horse led to significantly less total interactions and lower levels of aggression than the introduction of single horses, both immediately and after several days of observing the new group. Additionally, by observing the behaviour of the horses during everyday sociality I could develop a formula describing the interrelationship between expected aggression level and enclosure size per horse. The curve takes an exponential shape. Starting from a space allowance of 300 m2 and more per horse, the amount of aggressions per hour approaches zero. For the reduction of aggression levels and injury risks in socially kept horses I recommend an enclosure size of at least 300 m2 per horse (chapter 2). I further investigated the stress level of the introduced animals. Horses which were immediately introduced did not show elevated faecal GCMs. In contrast, horses which were introduced after an observation period had slightly elevated values 2 and 3 days after the introduction. For horses introduced together with an integration horse faecal GCMs were significantly above the baseline value on the day of introduction and 1 day after it. These differences between introduction techniques indicate that the introduction event itself is not as stressful as previously assumed. Rather standing together with an integration horse and not being able to integrate immediately into the complete group elicits stress in horses (chapter 3). In the commentary of chapter 4 several studies are discussed which failed to demonstrate social learning in horses. It is argued that they did not consider important aspects which could have an influence, such as the dominance status or the social background of the horses (chapter 4). In chapter 5 a social feeding situation was investigated. The social rank as well as the position of conspecifics affected the feeding strategy of horses. Domestic horses used social cognition and strategic decision making in order to decide where to feed. When possible they tended to return to the same, continuously supplied feeding site and switched to an ?avoidance tendency? in the presence of dominant horses or when another horse was already feeding there (chapter 5). One possibility to recognize group members is through olfactory recognition. In chapter 6 it is shown that horses are able to distinguish their own from their conspecifics? faeces. In addition, they paid most attention to the faeces of those group members from which they received the highest amount of aggressive behaviour (chapter 6). Horses show cognitive abilities because they are able to use humans as local enhancement cues when searching for food, independently of their body posture or gaze consistency when the persons face them. Moreover, they seem to orientate on the attention of familiar persons more than of unfamiliar persons (chapter 7). Altogether, the results of this thesis provide further support for the view that horses show good conflict resolution strategies. They are perfectly able to deal with the conflict situation of being introduced to new group members, and the introduction event itself is not as stressful as previously assumed. It is rather suggested that standing together with an integration horse and not being able to integrate immediately into the complete group elicits stress in horses. All additional experimental set-ups could demonstrate that horses are well capable of social cognition.
Keywords: Pferd; Equiden; Eingliederungstechnik; Integrationspferd; Stress; Cortisol; Endokrine Reaktion; Gruppenhaltung; Verletzungsgefahr; Aggression; Futterplatzwahl; Kot; Geruchssinn; Mensch-Pferd Interaktion; horse; equids; introduction technique; integration horse; stress; cortisol; endocrine response; group housing; injury risk; aggression; feeding decision; faecal sample; olfaction; human-horse interaction
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Krueger, K., Farmer, K., & Heinze, J. (2014). The effects of age, rank and neophobia on social learning in horses. Anim. Cogn., 17(3), 645–655.
Abstract: Social learning is said to meet the demands of complex environments in which individuals compete over resources and co-operate to share resources. Horses (Equus caballus) were thought to lack social learning skills because they feed on homogenously distributed resources with few reasons for conflict. However, the horse’s social environment is complex, which raises the possibility that its capacity for social transfer of feeding behaviour has been underestimated. We conducted a social learning experiment using 30 socially kept horses of different ages. Five horses, one from each group, were chosen as demonstrators, and the remaining 25 horses were designated observers. Observers from each group were allowed to watch their group demonstrator opening a feeding apparatus. We found that young, low ranking, and more exploratory horses learned by observing older members of their own group, and the older the horse, the more slowly it appeared to learn. Social learning may be an adaptive specialisation to the social environment. Older animals may avoid the potential costs of acquiring complex and potentially disadvantageous feeding behaviours from younger group members. We argue that horses show social learning in the context of their social ecology, and that research procedures must take such contexts into account. Misconceptions about the horse’s sociality may have hampered earlier studies.
Keywords: Horse; Social learning; Sociality; Ecology; Social relationships
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Broucek, J., Ksac, P., & Uhrincat, M. (2003). The effect of sire line on learning and locomotor behaviour of heifers. Czech J. Anim. Sci, 48, 387–394.
Abstract: ABSTRACT: e aim of this study was to test the effect of sire line on maze learning ability and locomotor behaviour
in open-field tests of heifers, consistency over the time of grid crossing and relationship between the time of traversing the maze and grid crossings in open-field tests, respectively. We analysed the results of ethological tests for 54 Holstein heifers that descended from 7 sires. Maze behaviour was observed at the age of 15 weeks, an open-field test was applied at two age periods, 16 weeks and 18 months. We found out highly significant differences in the time of traversing the maze between heifers of different sire origin (P < 0.01). e number of grid crossings over the five minutes of the open-field test did not differ between the daughters of the age of 16 weeks and 18 months. Repeatability between the number of grid crossings at the age of 16 weeks and 18 months was proved by significant correlation (r = 0.2713*). On the contrary, significant relationships between the times of traversing the maze and locomotor behaviour in the open-field test (r =-0.3739*) were found only when the sequence of observations followed after a week pause (age of 15 and 16 weeks). Keywords: heifers; sire; maze; open-field test; repeatability; learning; locomotor behaviour relationship
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Carroll, G. L., Matthews, N. S., Hartsfield, S. M., Slater, M. R., Champney, T. H., & Erickson, S. W. (1997). The effect of detomidine and its antagonism with tolazoline on stress-related hormones, metabolites, physiologic responses, and behavior in awake ponies. Vet Surg, 26(1), 69–77.
Abstract: Six ponies were used to investigate the effect of tolazoline antagonism of detomidine on physiological responses, behavior, epinephrine, norepinephrine, cortisol, glucose, and free fatty acids in awake ponies. Each pony had a catheter inserted into a jugular vein 1 hour before beginning the study. Awake ponies were administered detomidine (0.04 mg/kg intravenously [i.v.]) followed 20 minutes later by either tolazoline (4.0 mg/kg i.v.) or saline. Blood samples were drawn from the catheter 5 minutes before detomidine administration (baseline), 5 minutes after detomidine administration, 20 minutes before detomidine administration which was immediately before the administration of tolazoline or saline (time [T] = 0), and at 5, 30, and 60 minutes after injections of tolazoline or saline (T = 5, 30, and 60 minutes, respectively). Compared with heart rate at T = 0, tolazoline antagonism increased heart rate 45% at 5 minutes. There was no difference in heart rate between treatments at 30 minutes. Blood pressure remained stable after tolazoline, while it decreased over time after saline. Compared with concentrations at T = 0, tolazoline antagonism of detomidine in awake ponies resulted in a 55% increase in cortisol at 30 minutes and a 52% increase in glucose at 5 minutes. The change in free fatty acids was different for tolazoline and saline over time. Free fatty acids decreased after detomidine administration. Free fatty acids did not change after saline administration. After tolazoline administration, free fatty acids increased transiently. Tolazoline tended to decrease sedation and analgesia at 15 and 60 minutes postantagonism. Antagonism of detomidine-induced physiological and behavioral effects with tolazoline in awake ponies that were not experiencing pain appears to precipitate a stress response as measured by cortisol, glucose, and free fatty acids. If antagonism of an alpha-agonist is contemplated, the potential effect on hormones and metabolites should be considered.
Keywords: Adrenergic alpha-Antagonists/administration & dosage/*pharmacology; Animals; Behavior, Animal/drug effects/physiology; Blood Glucose/metabolism; Blood Pressure/drug effects/physiology; Consciousness/physiology; Dose-Response Relationship, Drug; Drug Interactions; Epinephrine/blood; Fatty Acids, Nonesterified/blood; Female; Heart Rate/drug effects/physiology; Horse Diseases/metabolism/physiopathology/psychology; Horses/blood/metabolism/*physiology; Hydrocortisone/blood; Hypnotics and Sedatives/administration & dosage/*pharmacology; Imidazoles/administration & dosage/*pharmacology; Injections, Intravenous; Male; Norepinephrine/blood; Receptors, Adrenergic, alpha/drug effects/*physiology; Stress/metabolism/physiopathology/veterinary; Time Factors; Tolazoline/administration & dosage/*pharmacology
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Romano, N., Vitale, F., Alesi, D. R., Bonura, F., La Licata, R., Intonazzo, V., et al. (1992). The changing pattern of human immunodeficiency virus type 1 infection in intravenous drug users. Results of a six-year seroprevalence study in Palermo, Italy. Am J Epidemiol, 135(11), 1189–1196.
Abstract: A cross-sectional seroepidemiologic study was carried out between 1985 and 1990 in 1,567 heterosexual intravenous drug users who had been seen at the AIDS Regional Reference Center in Palermo, Italy, to evaluate the rate of human immunodeficiency virus type 1 (HIV-1) seroprevalence in this group and its long-term trend. Sixty serum samples collected from drug users in 1980 and 1983, before the founding of the Center (1985), were tested as well. Some demographic and behavioral risk factors were studied in a subgroup of intravenous drug users enrolled in 1985, 1987, and 1990 for their possible association with HIV-1. These factors were also studied in relation to hepatitis B virus infection, since both viruses share the same modes of spread. These drug users had a higher prevalence of markers for hepatitis B virus than of HIV-1 antibodies, and the prevalence rates in sera collected declined over time for both infections. The presence of both antibodies to HIV-1 and markers for hepatitis B virus was independently associated with the age of the drug user, the duration of drug use, and the year of serum collection. Antibodies to HIV-1 were observed more frequently in females than in males. No relation was found between education or employment status and the presence of HIV-1 antibodies or hepatitis B virus markers. Although new HIV-1 infections still occur, the decline in seroprevalence observed at the end of the 1980s might be related to modifications in social behavior among newer drug users, partial exhaustion of the susceptible population, and increasing risk awareness in more experienced users.
Keywords: Acquired Immunodeficiency Syndrome/*epidemiology; Adolescent; Adult; Chi-Square Distribution; Cross-Sectional Studies; Female; HIV Antibodies/blood; HIV Infections/*epidemiology; HIV Seroprevalence/*trends; *Hiv-1; Hepatitis B Antibodies/blood; Hepatitis B Surface Antigens/blood; Heroin; Humans; Incidence; Italy/epidemiology; Logistic Models; Male; Multivariate Analysis; Odds Ratio; Prevalence; Risk Factors; Substance Abuse, Intravenous/*epidemiology; Time Factors
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Connor, R. C., Wells, R. S., Mann, J., & Read, A. J. (2000). The bottlenose dolphin: Social relationships in a fission-fusion society. In J. Mann, R. C. Connor, P. L. Tyack, & H. Whitehead (Eds.), Cetacean Societies: Field Studies of Dolphins and Whales. (pp. 91–126). Chicago: University of Chicago Press.
Abstract: Book Description
“Part review, part testament to extraordinary dedication, and part call to get involved, Cetacean Societies highlights the achievements of behavioral ecologists inspired by the challenges of cetaceans and committed to the exploration of a new world.”-from the preface by Richard Wrangham Long-lived, slow to reproduce, and often hidden beneath the water's surface, whales and dolphins (cetaceans) have remained elusive subjects for scientific study even though they have fascinated humans for centuries. Until recently, much of what we knew about cetaceans came from commercial sources such as whalers and trainers for dolphin acts. Innovative research methods and persistent efforts, however, have begun to penetrate the depths to reveal tantalizing glimpses of the lives of these mammals in their natural habitats. Cetacean Societies presents the first comprehensive synthesis and review of these new studies. Groups of chapters focus on the history of cetacean behavioral research and methodology; state-of-the-art reviews of information on four of the most-studied species: bottlenose dolphins, killer whales, sperm whales, and humpback whales; and summaries of major topics, including group living, male and female reproductive strategies, communication, and conservation drawn from comparative research on a wide range of species. Written by some of the world's leading cetacean scientists, this landmark volume will benefit not just students of cetology but also researchers in other areas of behavioral and conservation ecology as well as anyone with a serious interest in the world of whales and dolphins. Contributors are Robin Baird, Phillip Clapham, Jenny Christal, Richard Connor, Janet Mann, Andrew Read, Randall Reeves, Amy Samuels, Peter Tyack, Linda Weilgart, Hal Whitehead, Randall S. Wells, and Richard Wrangham. |
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Alexander, F., & Nicholson, J. D. (1968). The blood and saliva clearances of phenobarbitone and pentobarbitone in the horse. Biochem Pharmacol, 17(2), 203–210.
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Steinhoff, H. J., Schrader, J., & Schlitter, J. (1992). Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals. Biochim Biophys Acta, 1121(3), 269–278.
Abstract: Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.
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