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Herholz, C. P., Gerber, V., Tschudi, P., Straub, R., Imhof, A., & Busato, A. (2003). Use of volumetric capnography to identify pulmonary dysfunction in horses with and without clinically apparent recurrent airway obstruction. Am J Vet Res, 64(3), 338–345.
Abstract: OBJECTIVE: To investigate whether volumetric capnography indices could be used to differentiate between horses without recurrent airway obstruction (RAO) and horses with RAO that were in clinical remission or that had clinically apparent RAO. ANIMALS: 70 adult Swiss Warmblood horses (20 used for pleasure riding and 50 used for dressage or show jumping). PROCEDURE: Horses were allocated to 4 groups on the basis of history, clinical signs, results of endoscopy, and cytologic findings (group 1, 21 healthy horses; group 2, 22 horses with RAO that were in remission; group 3, 16 horses with mild RAO; group 4, 11 horses with exacerbated RAO). Expiratory volume and CO2 curves were recorded by use of a computerized ultrasonic spirometer. Volumetric capnograms were plotted, and derived indices were calculated. RESULTS: Dead-space volume (VD) was calculated by use of the Bohr equation (VD(Bohr)) and for physiologic VD (VD(phys)). Ratios for VD(Bohr) to expiratory tidal volume (VT) and VD(phys) to V(T) as well as an index of effective CO2 elimination were significantly different among groups of horses. Age and use of the horses also significantly affected volumetric capnography indices. CONCLUSIONS AND CLINICAL RELEVANCE: Ratios of VD(Bohr) to VT and VD(phys) to VT as well as an index of effective CO2 elimination were sufficiently sensitive measures to distinguish between healthy horses and horses with RAO in remission. To optimize the ability of volumetric capnography indices to differentiate among horses in heterogeneous populations, it is important to account for effects of age and specific use of the horses.
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Henry, S., Zanella, A. J., Sankey, C., Richard-Yris, M. - A., Marko, A., & Hausberger, M. (2012). Adults may be used to alleviate weaning stress in domestic foals (Equus caballus). Physiology & Behavior, 106(4), 428–438.
Abstract: The present study aims to investigate whether the presence of unrelated adult horses at weaning would reduce the social stress of weaning and the emergence of undesirable behaviours. We tested this hypothesis in 32 domestic foals by comparing short and medium term behavioural and physiological responses to weaning in foals maintained in homogeneous groups of peers (PW) to those of foals grouped with both peers and unrelated adults (AW). In total, three trials were conducted, which each trial consisting of one AW group and one PW group. In all foals, weaning was followed by increased vocalization, increased locomotion and increased salivary cortisol concentration. However, signs of stress were less pronounced and shorter in duration in weanlings housed with unrelated adults (e.g. whinnies: p < 0.05; salivary cortisol: p < 0.05). Only foals without adults exhibited increased aggressiveness towards peers (p < 0.05) and abnormal behaviours (p < 0.05) such as excessive wood-chewing and redirected sucking towards peers. In conclusion, introducing adults to minimize weaning stress in foals and later on aggressiveness and abnormal behaviours appears as the most promising approach to date.
Keywords: Weaning; Social influence; Abnormal behaviours; Young-adult interactions; Welfare; Horse
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Henry, S., Hemery, D., Richard, M. - A., & Hausberger, M. (2005). Human-mare relationships and behaviour of foals toward humans. Appl. Anim. Behav. Sci., 93(3-4), 341–362.
Abstract: We studied experimentally whether horse dams influenced foals' relationships with humans. We investigated the influence of the establishment of positive human-mare relationships on foals' behaviour toward humans. Forty-one foals and their dams were involved in this experiment. Half of the mares were softly brushed and fed by hand during a short period (total of 1.25 h) during the first 5 days of their foals' lives (experimental group, n = 21). The other mares were not handled experimentally and their foals received no contact with the experimenter (control group, n = 20). The reactions of both experimental and control foals were recorded under various conditions, first, for 5 min in the presence of a motionless experimenter, when foals were 15 and 30-35 days old, then in an approach test when they were 15 days old and in a saddle-pad tolerance test when they were 30-35 days old. Finally, approach-stroking tests were performed successively by the familiar experimenter when foals were 11-13 months old and by an unfamiliar person when they were 13-15 months old. Several observations strongly suggest that mares can influence their foals' behaviour toward humans: (1) during the handling procedure, experimental foals of protective mares were further from the handler than foals of calm mares (p < 0.001); (2) experimental foals remained, at all ages, closer to the experimenter (p < 0.05) and initiated more physical contacts (sniffing, licking, etc.) with the experimenter (p < 0.05) than control foals; (3) avoidance and flight responses of experimental foals were considerably reduced during approaches by the experimenter (p < 0.01) and they accepted saddle-pads on their backs more easily (p < 0.01) and more quickly (p < 0.01) than control foals. Lastly, the consequences of handling mares had effects that lasted at least until foals were one year old (p < 0.05) and became generalized from experimenter to unfamiliar humans, who could approach and stroke experimental foals rapidly during a test (p < 0.05). This is the first report of an attempt to use observation of mother by foals to facilitate human-foal relationships. The procedure is simple, takes little time and can easily be applied to any dam-foal pair, as it is not intrusive and presents no risks of disrupting mare-foal bonds.
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Henning, J. M., & Zentall, T. R. (1981). Imitation, social facilitation, and the effects of ACTH 4-10 on rats' bar-pressing behavior. Am J Psychol, 94(1), 125–134.
Abstract: The effects of ACTH 4-10 on rats' imitation learning was examined during the acquisition and extinction of a bar-press response for water reinforcement. Rats were exposed to either a bar-pressing conspecific (OB), an experimentally naive conspecific (ON), or an empty box (OE) during bar-press acquisition. In a factorial design, each rat was then exposed to one of the same three conditions during extinction. An 80 mcg dose of ACTH 4-10 was administered to half of the rats in each group prior to observation. Performance differences during acquisition were generally small, but significant performance differences during extinction were found. Social facilitation was indicated by the finding that rats extinguished in the presence of a conspecific exhibited significantly greater resistance to extinction than rats extinguished in the presence of an empty box. An imitation effect was also found. Rats that observed a bar-pressing conspecific during both acquisition and extinction (group OB-OB) showed significantly greater resistance top extinction than did groups OB-ON, CB-OE, or OE-OE. There were no significant effects of the hormone, however, relative to saline controls.
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Heitor, F., & Vicente, L. (2008). Maternal care and foal social relationships in a herd of Sorraia horses: Influence of maternal rank and experience. Appl. Anim. Behav. Sci., 113(1-3), 189–205.
Abstract: The influence of maternal rank and experience on patterns of maternal care and social relationships of foals were investigated in a managed herd of Sorraia horses, Equus caballus. Social interactions and spatial relationships of 13 foals (seven females and six males) born to seven mares were examined from birth to 10 months of life, within the three major periods of foal development. Conflict over suckling between dam and foal was not generally affected by rank and experience, but higher-ranking mothers allowed more suckling during late lactation than lower-ranking mothers. Foals of higher-ranking mares spent more time in proximity to the mother during socialization. Maternal rank and experience did not significantly affect maternal protectiveness, foal independence from the mother or the development of affiliative relationships between foals and group members. Foals of higher-ranking mares received lower frequencies of aggression from other horses only in the first month of life. Dominance relationships among foals depended mainly on aggressiveness and were not associated with maternal rank. The large variability in maternal behaviour, the absence of a significant association between maternal rank and body condition at parturition and the stable social environment within this herd may partly account for the reported results.
Keywords: Horse; Rank; Experience; Maternal care; Social relationships
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Heitor, F., & Vicente, L. (2010). Dominance relationships and patterns of aggression in a bachelor group of Sorraia horses (Equus caballus). J. Ethol., 28(1), 35–44.
Abstract: Abstract The influence of individual factors on dominance rank and the relationship between rank distance and patterns of aggression predicted by models of evolutionarily stable strategies (ESS) of animal conflict were investigated in a managed bachelor group of Sorraia horses, Equus caballus. The group was composed of four to six stallions 3- to 12-years-old during the study period. The dominance hierarchy was significantly linear and rank was not related to age, weight, height or aggressiveness. Frequency and intensity of agonistic interactions were low, but higher-ranking stallions did not receive lower aggressiveness than lower-ranking stallions. There was some evidence that dominance relationships were more contested among close-ranking stallions, as predicted. Agonistic-related interactions among close-ranking stallions served similar functions to those among distant-ranking stallions, but the latter interacted more frequently than expected for access to resting sites and/or resting partners. Therefore, we found some evidence that agonistic-related interactions among distant-ranking stallions play a larger role in providing access to valuable and defendable resources than those among close-ranking stallions. Nevertheless, the fact that space to escape from aggression was limited and breeding access was independent from dominance rank may have reduced the benefits relative to costs of aggression and therefore limited the occurrence of contests over dominance and resources.
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Heitor, F., & Vicente, L. (2010). Affiliative relationships among Sorraia mares: influence of age, dominance, kinship and reproductive state. J. Ethol., 28(1), 133–140.
Abstract: Abstract Affiliative relationships among mares were examined in a managed group of Sorraia horses, Equus caballus, over a 3-year period. We assessed the influence of age, dominance, kinship and reproductive state on the strength of affiliative relationships and diversity of partners. The herd comprised 9–11 mares that had known each other since birth, their foals and a stallion that remained in the group exclusively during the breeding season. In contrast to a previous study, kinship did not significantly affect bonds. Mares tended to spend more time in proximity to those in the same reproductive state. Affiliative relationships among mares were relatively stable but their strength decreased after foaling, possibly as a function of foal protection and bonding between dam and foal. There was no consistent evidence that mares disengaged from affiliative relationships with increasing age. As expected, dominant mares and barren mares contributed the most to affiliative relationships. Dominance rank increased with age, but dominance relationships were stable and did not change after foaling. Overall, reproductive state was the factor that had the most consistent influence on affiliative relationships among Sorraia mares.
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Heitor, F., do Mar Oom, M., & Vicente, L. (2006). Social relationships in a herd of Sorraia horses: Part II. Factors affecting affiliative relationships and sexual behaviours. Behav. Process., 73(3), 231–239.
Abstract: The influence of age, dominance rank, kinship and aggressiveness over affiliative relationships and sexual behaviours were analysed in a herd of Sorraia horses, Equus caballus, kept under extensive management. Subjects were 10 adult mares 5-18 years old that had known each other since birth, and a stallion introduced into the group for breeding for the first time. Kinship coefficient and dominance rank were the most important factors affecting affiliative relationships. Bonds were reciprocal and stronger among mares with higher kinship. Mares spent more time in proximity to close-ranking and lower-ranking females. Mares with stronger affiliative relationships or higher relatedness were not less aggressive towards each other. Affiliative relationships between the stallion and the mares were not reciprocal: lower-ranking mares formed stronger bonds with the stallion but he preferred the less genetically related mares for proximity. However, the stallion was involved in sexual behaviours more frequently with the mares that were more genetically related to him. These results suggest that kinship beyond close relatives may affect affiliative relationships both among familiar and among unfamiliar horses. However, the influence of kinship does not imply that horses possess a kin recognition system and alternative explanations are discussed.
Keywords: Horse; Equus; Affiliative relationship; Rank; Kinship; Aggressiveness
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Hebenbrock, M., Due, M., Holzhausen, H., Sass, A., Stadler, P., & Ellendorff, F. (2005). A new tool to monitor training and performance of sport horses using global positioning system (GPS) with integrated GSM capabilities. Dtsch Tierarztl Wochenschr, 112(7), 262–265.
Abstract: Global Positioning Systems (GPS) are considered suitable to monitor the position and velocity of horses during cross-country competition or in training. Furthermore, simultaneous recording of life data such as heart rate could be useful to assess the horse's condition during exercise. To test the suitability and reliability of a commercially available GPS system with integrated heart rate recording system and with built in GSM for data transmission, the Fidelak Equipilot Type EP-2003-15/G-2.11 (EP-15/G) was evaluated first for reliability of pulse recording from a pulse generator within the physiological range of horses; furthermore distance, velocity and heart rate recordings were carried out on a standard 1000 m field track with five repetitions. Agreement (% deviation from actually measured distance and from stopwatch-distance based velocity calculations) and variability (Coefficient of Variation for distance, velocity, heart rate) were calculated. From the results it was safe to assume that the heart rate sensor recorded horse heart rates at a high degree of accuracy. Overall distances and velocities are in high agreement with actually measured values. However, overall variability expressed in terms of relative variability (C.V.) is smaller for distance recording (C.V. 0.68%) when compared to velocity (C.V. 1.01%). The system tested is suitable and reliable for simultaneously recording of distance, velocity and heart rates for horses during cross country exercise. GPS-based monitoring of movement along with simultaneous recording of physiological data and the possibility to call upon data will not only be of benefit for training horses or for surveillance during competition, it may also be suitable for distant patient monitoring and in behavioural studies as well as in veterinary medicine in general.
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Hazem, A. S. (1978). [Collective review: Salmonella paratyphi in animals and in the environment]. Dtsch Tierarztl Wochenschr, 85(7), 296–303.
Keywords: Animals; Animals, Domestic; Animals, Wild; Bird Diseases/epidemiology; Brachyura; Cat Diseases/epidemiology; Cats; Cattle; Cattle Diseases/epidemiology; Dog Diseases/epidemiology; Dogs; Ecology; Environment; Fish Diseases/epidemiology; Germany, West; Horse Diseases/epidemiology; Horses; Mollusca; Poultry Diseases/epidemiology; Salmonella Infections, Animal/*epidemiology; *Salmonella paratyphi A; Sheep; Sheep Diseases/epidemiology; Snails; Swine; Swine Diseases/epidemiology
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