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Huizinga, H. A., Korver, S., & van der Meij, G. J. W. (1991). Stationary performance testing of stallions from the Dutch Warmblood riding horse population. 2. Estimated heritabilities of and correlations between successive judgements of performance traits. Livestock Production Science, 27(2-3), 245–254.
Abstract: The length of test period of stationary performance testing (SPT) of stallions of the Dutch Warmblood riding horse population is evaluated. Heritability of successive judgements of traits and the phenotypic and genetic relations between successive judgements are estimated. Data from 1983-1988 are used, covering scores from 206 mostly 3-year-old stallions. Ten subjectively scored traits are considered: walk, trot, canter, riding ability, jumping ability, free jumping, cross country, character, stable behaviour, training report. Traits are successively scored at about 25, 50, 80 and 100 days in SPT. Missing scores are predicted on basis of the available scores using multiple partial regression coefficients. Validity of this method is checked in an independent data set for walk, trot and canter. The correlations between predicted and realized scores average 0.74, 0.77 and 0.79 when first, first and second, and first, second and third judgements are available, respectively. Variance and covariance components are estimated by restricted maximum likelihood (REML) procedures. Data from SPT are analysed using an animal model. Estimates of heritability are high and constant for gaits during the successive judgements. Except for stable behaviour estimates of heritability, the traits decrease slightly during the successive judgements. Estimates of the phenotypic and genetic correlations between successive judgements are high. It is concluded that length of SPT can be shortened and selection during SPT can be intensified.
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Denoix, J. M. (1991). Approche mecanique des allures et du saut chez le cheval. Science & Sports, 6(2), 117–124.
Abstract: Resume La locomotion du cheval implique des contraintes mecaniques elevees sur les os, les articulations, les muscles et les tendons. Son etude permet de mieux connaitre les interventions actives ou passives de ces organes au cours des allures et du saut. Ces elements sont utiles pour la mise en oeuvre rationnelle d'exercices d'entrainement chez le cheval de sport ou de courses, en fonction des exigences de la discipline et des eventuels problemes locomoteurs du sujet. L'etude mecanique de la locomotion du cheval est par ailleurs indispensable pour l'amelioration de la connaissance des boiteries. Elle permet de preciser la genese des lesions osteoarticulaires et musculo-tendineuses et contribue a ameliorer leur traitement.Summary Locomotion of the horse is correlated with a great variety of mechanical stresses on bones, joints, muscles and tendons. Research on locomotion increases the knowledge of passive and active interventions of these structures during gaits and jump. These data are useful to manage the training of sport and jump horses, especially to fit with the particularities of the sport speciality and individual locomotor problems of horses. Beside, studies of locomotion in the horse are of importance to improve the knowledge of lamenesses. They contribute to precise the pathogenesis of osteoarticular and musculotendinous injuries and improve their treatment.
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Marinier, S. L., & Alexander, A. J. (1991). Selective grazing behaviour in horses: development of methodology and preliminary use of tests to measure individual grazing ability. Appl. Anim. Behav. Sci., 30(3-4), 203–221.
Abstract: Methods are described to assess horses' selective grazing ability that includes choosing, sorting and the adaptive value of this behaviour. Choosing ability was tested by the experimenter presenting pairs of cut plant species that were then alternated at each presentation until the test horse had taken three bites of one of the plant pair. The results were analysed in relation to five measures of choosing behaviour: (1) the strength of the choice; (2) correspondence between first bite and the final choice; (3) constancy of the choice over a number of trials; (4) the comparison of the horses' ranking of the species over a number of trials; (5) the constancy of the linear arrangement of the plants over a number of trials. Sorting ability was tested using two methods. A mixture of two plant species was presented either in a clamp or loose in a trough. Results were based on number and weight of plant residues. The adaptive value of the behaviour related to the bitterness of toxic plants. This bitterness was represented in testing by quinine sulphate and a poisonous Senecio species. An extremely bitter substance “Bitrex” was also used in this context but was totally accepted by the horses. The horses' reactions to these substances were monitored using a behavioural score chart. The results from 12 horses revealed that the horses differed individually in their grazing ability. On this basis, the horses were classified as efficient, semi-efficient, or inefficient grazers. This finding has practical implications in deciding which horses may safely graze on pastures infested with toxic plants.
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Luescher, U. A., McKeown, D. B., & Halip, J. (1991). Reviewing the causes of obsessive-compulsive disorders in horses. Vet. Med., 86, 527–530.
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Schulte, N., & Klingel, H. (1991). Herd Structure, Leadership, Dominance and Site Attachment of the Camel, Camelus Dromedarius. Behaviour, 118(1-2), 103–114.
Abstract: Social structure and relationships in a herd of captive camels were studied in Kenya. During day and night the herd split up irrespective of kinship. Partner preferences existed only in those camels who had previously been kept in a small group separated from the herd. Dominance relationships are anonymous with four levels: a) dominant breeding bulls, b) females and bachelors, c) subadults, and d) calves. No stable leadership was observed, but individual preferences in the walking order existed when the camels left and entered the enclosure. During the night most camels showed an amazing attachment to a particular resting site; in a new boma they used corresponding sites. During moon nights activity was greatly increased.
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Boesch, C. (1991). Teaching among wild chimpanzees. Anim. Behav., 41(3), 530–532.
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Mal, M. E., Friend, T. H., Lay, D. C., Vogelsang, S. G., & Jenkins, O. C. (1991). Behavioral responses of mares to short-term confinement and social isolation. Appl. Anim. Behav. Sci., 31(1-2), 13–24.
Abstract: Thirty-six mares, blocked by age and temperament score, were assigned to one of three treatment groups: pasture (P); confinement stalls (C), allowing social contact; isolation stalls (ISS), allowing no contact with conspecifics. After 48 h on treatment, the mares were observed in situ for 1 h. Medium temperament and highly reactive ISS mares spent more time eating grain (P<0.01) and exhibited more grain-eating bouts (P<0.03) than P and C mares. Calm P mares had longer forage-eating bouts than C and ISS mares (P<0.02). During a 15 min open-field test in a 23 m x 23 m pen after 72 h on treatment, ISS mares traveled farther (P<0.005) than C and P mares, spent more total time trotting (P<0.01) than C and P mares, and exhibited a greater number of trotting bouts (P<0.01) than both C and P mares. Isolated mares spent less total time standing during the open-field test than C (P<0.05) and P (P<0.01) mares, but exhibited a greater number of standing bouts than C (P<0.05) and P (P<0.01) mares. Isolated mares also exhibited a greater number of total activity bouts (P<0.01) during the open-field test than both C and P mares; P mares also exhibited fewer activity bouts than C mares (P<0.1). Results indicate that mares kept in confined and isolated environments showed greater motivation for movement and performance of a greater number of activities than those maintained on pasture with conspecifics.
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Judge, P. J. (1991). Dyadic and triadic reconciliation in pigtail macaques (Macaca nemestrina). Am. J. Primatol., 23, 225–237.
Abstract: The tendency in primates for former antagonists to approach and affiliate following aggression has been termed reconciliation because the response is thought to resolve social conflicts produced by aggression. In primate societies, however, an aggressive interaction between two individuals often spreads to include other group members, especially the kin of the combatants. If post conflict affiliation resolves aggressive conflicts in a group, then affiliative increases might occur between combatants and the kin of their opponents following aggression as well as between former opponents. This hypothesis was tested in a captive group of 39 pigtail macaques (Macaca nemestrina) by comparing affiliative response frequencies of combatants during the 5 minute period following aggression to affiliative response frequencies during 5 minute baseline periods not preceded by aggressive activity. Following aggression, affiliation rates increased between combatants and their opponents, aggressors and the kin of their opponents, and aggressors and their own kin. Additional analyses showed that aggression among kin was reconciled more often than aggression among nonkin. Recipients of aggression reconciled with their attackers more often than aggressors reconciled with their victims. Animals with similar dominance ranks reconciled proportionately more often than those with large rank disparities and aggressive infractions of a calculated dominance hierarchy were reconciled more often than attacks consistent with the hierarchy. Results suggest that both dyadic and triadic reconciliations occur in M. nemestrina and that compared to other primate species M. nemestrina exhibit a moderate-to-high conciliatory tendency.
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Mills, G. (1991). Kalahari Hyenas.
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Scheidhacker, M., Bender, W., & Vaitl, P. (1991). Die Wirksamkeit des therapeutischen Reitens bei der Behandlung chronisch schizophrener Patienten. Nervenarzt, 62(5), 283–287.
Abstract: After describing horse-riding as a facility in managing mentally ill patients, a program for chronic schizophrenic in-patients is presented. Clinical experience with this program and also results of a controlled study are reported. The therapeutic value and slope for horse-riding are discussed in relation to different diagnoses.
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