Hinrichs, K., Watson, E. D., & Kenney, R. M. (1990). Granulosa cell tumor in a mare with a functional contralateral ovary. J Am Vet Med Assoc, 197(8), 1037–1038.
Abstract: A functional corpus luteum was found in the ovary contralateral to the ovary with a granulosa cell tumor in a 24-year-old Standardbred mare. The mare was ovariectomized because she was to be used as a jump mare for collection of semen from stallions. The blood concentration of progesterone was 2.2 ng/ml, and the luteal tissue progesterone concentration was 6.3 micrograms/mg. Atrophy of the contralateral ovary is one of the major signs used in diagnosis of granulosa cell tumor; however, our findings indicate that the ovary contralateral to a granulosa cell tumor is not invariably nonfunctional.
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Huizinga, H. A., Boukamp, M., & Smolders, G. (1990). Estimated parameters of field performance testing of mares from the Dutch Warmblood riding horse population. Livestock Production Science, 26(4), 291–299.
Abstract: The field performance testing (FPT) of mares of the Dutch Warmblood riding horse population is evaluated. Phenotypic and genetic parameters of scored traits are estimated and the genetic relationship with performance of half-sibs in dressage and jumping competition are estimated. Data from 1984 to 1987 are used, covering scores from 2023 at least 3-year-old mares. Seven subjectively scored traits are considered, walk, trot, canter, riding ability, character, jumping ability and total score. Analysis of data is according to a sire model. Variance and covariance components are estimated by Restricted Maximum Likelihood (REML) procedures. Estimates of heritability are moderately low for gaits (average 0.19), jumping ability (0.15) and total score (0.17) and extremely low for riding ability (0.03) and character (0.06). Dressage in competition is most correlated with riding ability (0.83) and is moderately correlated with total score (0.41) from FPT of mares. Jumping competition is most correlated with jumping ability (0.48) and not correlated with total score (0.05) from field test of mares. Some possible bias owing to previous knowledge and preselection is discussed. It is concluded that efficiency of present FPT of mares is limited for selection of broodmares for dressage and jumping ability in competition.
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Philipsson, J., Arnason, T., & Bergsten, K. (1990). Alternative selection strategies for performance of the Swedish warmblood horse. Livestock Production Science, 24(3), 273–285.
Abstract: The Swedish riding horse population includes about 6000 broodmares and 150 breeding stallions. The overall breeding goal is to produce riding horses competitive in several disciplines, i.e. dressage as well as showjumping and eventing. The effectiveness of this multi-purpose objective was studied in alternative strategies for selecting stallions and mares as candidate dams for them. The alternative selection strategies for stallions included 1-stage (conformation), 2-stage (conformation and performance test) and 3-stage (conformation, performance test and competition results at advanced levels) selection schemes. The mare selection schemes included the corresponding 1- and 2-stage selection schemes. The results clearly showed the 2-stage selection procedure to be most efficient, especially for stallions. It is important that the intensity in selection after the performance test is kept high. Differences in defining the breeding objective are less important, provided the selection is based on a performance test including both dressage and jumping. According to the results, the development of the Swedish performance testing scheme, in which now only 30% of the tested stallions are selected for breeding, seems justified. In mare selection schemes, performance tests also seem to be justified, especially if jumping ability is to be improved. Differences between field and station tests are only minor and since the volume of testing can be much higher in the field this would allow a much stronger selection and should thus be preferred.
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Potter, G. D., & Yeates, B. F. (1990). Behavioral principles of training and management. The Horse, 2nd Edn, , 665–682.
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Cheney, D. L., & Seyfarth, R. M. (1990). How Monkeys See the World.
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Cords, M. (1990). 13th Cong. Int. Primat Soc.
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Tooze, Z. J., Harrington, F. H., & Fentress, J. C. (1990). Individually distinct vocalizations in timber wolves, Canis lupus. Anim Behav, 40.
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