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Author Huizinga, H.A.; van der Werf, J.H.J.; Korver, S.; van der Meij, G.J.W.
Title Stationary performance testing of stallions from the Dutch Warmblood riding horse population. 1. Estimated genetic parameters of scored traits and the genetic relation with dressage and jumping competition from offspring of breeding stallions Type Journal Article
Year (up) 1991 Publication Livestock Production Science Abbreviated Journal
Volume 27 Issue 2-3 Pages 231-244
Keywords dressage; genetic parameters; horse; jumping; performance; stallion
Abstract The stationary performance testing (SPT) of stallions as breeding candidates in the Dutch Warmblood riding horse population is evaluated. Genetic and phenotypic parameters of traits scored during SPT and the genetic correlation of these traits with performances in dressage and jumping competition from offspring of breeding stallions are estimated. Data from 1978-1988 are used, covering scores from 337 3-year-old stallions. Eight subjectively scored traits are considered. These traits are: walk; trot; canter; riding ability; show jumping; free jumping; cross country; character. SPT lasts for a period of 100 days. Data from SPT are analysed using an animal model. The relations between SPT of stallions and performances in jumping and dressage competition are analysed with an animal model for SPT data and a sire model for competition data. Variance and covariance components are estimated by restricted maximum likelihood (REML) procedures. Estimates of heritability are high (0.64) for gaits and riding ability, intermediate (0.41) for cross country and medium-high (0.31) for jumping. Estimated genetic correlation between show jumping scored during SPT and jumping in competition from offspring of breeding stallions is 0.84; for dressage this relation is 0.83. Some possible bias due to selection and the subjectivity of scoring is discussed. It is indicated that selection on SPT of stallions before entering breeding service is an effective tool to breed for ability of performance in competition.
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Call Number refbase @ user @ Serial 3962
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Author Huizinga, H.A.; Korver, S.; van der Meij, G.J.W.
Title Stationary performance testing of stallions from the Dutch Warmblood riding horse population. 2. Estimated heritabilities of and correlations between successive judgements of performance traits Type Journal Article
Year (up) 1991 Publication Livestock Production Science Abbreviated Journal
Volume 27 Issue 2-3 Pages 245-254
Keywords dressage; genetic parameters; horse; jumping; performance; stallion
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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Call Number refbase @ user @ Serial 3963
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Author Mal, M.E.; Friend, T.H.; Lay, D.C.; Vogelsang, S.G.; Jenkins, O.C.
Title Behavioral responses of mares to short-term confinement and social isolation Type Journal Article
Year (up) 1991 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.
Volume 31 Issue 1-2 Pages 13-24
Keywords
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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ISSN 0168-1591 ISBN Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 4820
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Author Mills, G.
Title Kalahari Hyenas Type Miscellaneous
Year (up) 1991 Publication Abbreviated Journal
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Call Number Equine Behaviour @ team @ Serial 4884
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Author Kraus-Hansen, A.E.; Fackelman, G.E.; Becker, C.; Williams, R.M.; Pipers, F.S.
Title Preliminary studies on the vascular anatomy of the equine superficial digital flexor tendon Type Journal Article
Year (up) 1992 Publication Equine veterinary journal Abbreviated Journal Equine Vet J
Volume 24 Issue 1 Pages 46-51
Keywords Angiography/veterinary; Animals; Exercise Test/veterinary; Forelimb; Horses/*anatomy & histology/surgery; Microcirculation; Microscopy, Electron, Scanning; Tendons/*blood supply/surgery/ultrastructure
Abstract The vascular and microvascular anatomy of normal equine superficial digital flexor tendons was studied by dissection of vinyl-perfused specimens and by microangiography on high detail film. The presence of an extensive intratendinous vascular latticework was confirmed, and a 'nutrient artery' described closely associated with the accessory ligament of the superficial digital flexor tendon (proximal check ligament). Circumferential stripping of the paratenon from the tendon to eliminate afferent vessels was performed bilaterally in three horses and unilaterally in a fourth, followed by a treadmill training regimen. No resulting intratendinous lesions could be documented on gross post mortem and histological examination at three, 10, or 35 days post operatively. There was mild paratendinous proliferation in all instances. In one horse, four intratendinous ligatures were placed within the medial and lateral borders of the contralateral tendon to isolate further from its blood supply a 10 cm segment. Gross lesions at 35 days post operatively included a marked paratendinous response involving the entire 10 cm segment, and a darkened, soft focus within the core of the tendon. Histopathology and electron microscopy demonstrated focal degeneration. It was concluded that the blood supply of the normal equine superficial digital flexor tendon is primarily intratendinous, rather than paratendinous as previously thought. The lesions in one horse similar to those in naturally occurring tendinitis supported a vascular aetiology of the disease, and set the groundwork for studies aimed at the development of a clinically relevant tendinitis model.
Address Department of Surgery, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536
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Language English Summary Language Original Title
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Series Volume Series Issue Edition
ISSN 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:1555540 Approved no
Call Number refbase @ user @ Serial 151
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Author Dugatkin, L.A.; Godin, J.G.
Title Reversal of female mate choice by copying in the guppy (Poecilia reticulata) Type Journal Article
Year (up) 1992 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci
Volume 249 Issue 1325 Pages 179-184
Keywords Acclimatization; Animals; *Choice Behavior; Female; Male; Poecilia; *Sexual Behavior, Animal
Abstract Ever since Fisher (1958) formalized models of sexual selection, female mate choice has been assumed to be a genetically determined trait. Females, however, may also use social cues to select mates. One such cue might be the mate choice of conspecifics. Here we report the first direct evidence that a female's preference for a particular male can in fact be reversed by social cues. In our experiments using the Trinidadian guppy (Poecilia reticulata), this reversal was mediated by mate-copying opportunities, such that a female (the 'focal' female) is given the opportunity to choose between two males, followed by a period in which she observes a second female (the 'model' female) displaying a preference for the male she herself did not prefer initially. When allowed to choose between the same males a second time, compared with control tests, a significant proportion of focal females reversed their mate choice and copied the preference of the model female. These results provide strong evidence for the role of non-genetic factors in sexual selection and underlie the need for new models of sexual selection that explicitly incorporate both genetic and cultural aspects of mate choice.
Address Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
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ISSN 0962-8452 ISBN Medium
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Notes PMID:1360679 Approved no
Call Number Serial 1824
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Author Harkins, J.D.; Kamerling, S.G.; Church, G.
Title Effect of competition on performance of thoroughbred racehorses Type Journal Article
Year (up) 1992 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol
Volume 72 Issue 3 Pages 836-841
Keywords Age Factors; Animals; Anxiety/physiopathology; Competitive Behavior/*physiology; Exertion/*physiology; Fatigue/physiopathology; Female; Heart Rate; Horses/*physiology; Lactates/blood; Lactic Acid; Male; Sex Characteristics
Abstract The effect of competition and the influence of age and sex on performance were examined in a study of 18 Thoroughbred racehorses. The horses performed two solo and two competitive runs at 1,200 and 1,600 m for a total of eight runs. No group ran faster during competition, which may have been a reflection of the quality of horses used for this study and their susceptibility to stress-induced impairment of performance. Males showed no significant difference between competitive and solo run times, whereas females were consistently slower during competition. Males ran significantly faster than females in all runs. There was no difference in run times due to age, which may have been due to the high mean age (5.9 yr) of the group. The slower competitive run times may have occurred because of an earlier onset of fatigue when compared with solo runs. Plasma lactate was significantly greater for the 1,200-m competitive than for the solo runs.
Address Department of Veterinary Physiology, Pharmacology, and Toxicology, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803
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Language English Summary Language Original Title
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ISSN 8750-7587 ISBN Medium
Area Expedition Conference
Notes PMID:1568979 Approved no
Call Number refbase @ user @ Serial 1947
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Author Dugatkin, L.A.; Godin, G.J.
Title Predator inspection, shoaling and foraging under predation hazard in the Trinidadian guppy,Poecilia reticulata Type Journal Article
Year (up) 1992 Publication Environmental Biology of Fishes Abbreviated Journal
Volume 34 Issue 3 Pages 265-276
Keywords Antipredation – Social group – Feeding – Predation risk – Trade-off – Fish
Abstract Guppies,Poecilia reticulata, living in stream pools in Trinidad, West Indies, approached a potential fish predator (a cichlid fish model) in a tentative, saltatory manner, mainly as singletons or in pairs. Such behavior is referred to as predator inspection behavior. Inspectors approached the trunk and tail of the predator model more frequently, more closely and in larger groups than they approached the predator's head, which is presumably the most dangerous area around the predator. However, guppies were not observed in significantly larger shoals in the stream when the predator model was present. In a stream enclosure, guppies inspected the predator model more frequently when it was stationary compared to when it was moving, and made closer inspections to the posterior regions of the predator than to its head. Therefore, the guppies apparently regarded the predator model as a potential threat and modified their behavior accordingly when inspecting it. Guppies exhibited a lower feeding rate in the presence of the predator, suggesting a trade-off between foraging gains and safety against predation. Our results further suggest that predator inspection behavior may account for some of this reduction in foraging. These findings are discussed in the context of the benefits and costs of predator inspection behavior.
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Call Number Equine Behaviour @ team @ Serial 2176
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Author Dvoinos, G.M.; Kharchenko, V.A.; Zviagnitsova, N.S.
Title The characteristics of the helminth community in the Turkmen kulan (Equus hemionus) Type Journal Article
Year (up) 1992 Publication Parazitologiia Abbreviated Journal Parazitologiia
Volume 26 Issue 3 Pages 246-251
Keywords Animals; Female; Helminthiasis/parasitology; Helminthiasis, Animal; Helminths/classification/*isolation & purification; Male; Perissodactyla/*parasitology; Turkmenistan; Ukraine
Abstract The helminth fauna of 24 kulans from Askaniya-Nova and Badkhyz was studied. 42 species of helminths were found, 34 of which belong to strongylids. The helminth species composition of kulan is similar to that of other species of horses. This is a result of an intensive parasite exchange in the historical past when numerous populations of different Equidae species made long seasonal migrations over steppe inter-river lands of Asia and grazed for some time on common pastures.
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Language Russian Summary Language Original Title K kharakteristike soobshchestva gel'mintov turkmenskogo kulana (Equus hemionus)
Series Editor Series Title Abbreviated Series Title
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ISSN 0031-1847 ISBN Medium
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Notes PMID:1408368 Approved no
Call Number Equine Behaviour @ team @ Serial 2285
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Author Mills, M.G.L.; Shenk, M.G.L.
Title Predator--Prey Relationships: The Impact of Lion Predation on Wildebeest and Zebra Populations Type Journal Article
Year (up) 1992 Publication The Journal of Animal Ecology Abbreviated Journal T. J. Anim. Ecol.
Volume 61 Issue 3 Pages 693-702
Keywords
Abstract 1. The role of lion Panthera leo predation in the dynamics of blue wildebeest Connochaetes taurinus and zebra Equus burchelli populations was investigated through simulation models. The data used in the models were from intensive observations over 4 years in the south-east of the Kruger National Park. 2. Population estimates of wildebeest and zebra were made from aerial surveys, sex and age ratios from ground counts. Lion numbers were determined from observations of marked and radio-collared animals. Predation was studied by following lions for continuous periods of up to 336 h. 3. Two models were constructed. Model 1 ascertained the number of killing lions (adult females) that could be supported by each prey population while remaining stable. A single model was constructed for the sedentary wildebeest population. A summer and winter model was constructed for the semi-migratory zebra population. The sensitivity of the parameters in the model was tested by changing their value by 10%. In model 2, the kill age structure for each species was changed to determine the number of killing lions the altered prey selection parameters could support. 4. There was no difference in the vulnerability of either species to predation. Zebra foals (<1 year) were killed more frequently than expected. No selection for sex or by season could be found for either species. 5. Model 1 predicted that the wildebeest population stabilizes with 7.7 killing lions, close to the number in the study area. The winter zebra population stabilizes with 6.8 killing lions and the summer zebra population with 19.4. Manipulation of kill rate followed by adult fecundity rate had the greatest effect on population size of both species. In model 2, wildebeest predation was made selective towards calves and zebra predation was made non-selective for sex and age. With these parameters the wildebeest population stabilizes with 10.7 killing lions and the zebra population with 5.4 in winter and 15.1 in summer. 6. The models suggest that lion predation affected wildebeest more severely than zebra during the study. This was through the way in which lions selected their prey, and because of the sedentary behaviour of the wildebeest, as opposed to the semi-migratory behaviour of the zebra.
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Call Number Equine Behaviour @ team @ Serial 2376
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