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Author Lucas, Z.; Raeside, J.I.; Betteridge, K.J. openurl 
  Title Non-invasive assessment of the incidences of pregnancy and pregnancy loss in the feral horses of Sable Island Type Journal Article
  Year (up) 1991 Publication Journal of Reproduction and Fertility. Supplement Abbreviated Journal J Reprod Fertil Suppl  
  Volume 44 Issue Pages 479-488  
  Keywords Abortion, Veterinary/*epidemiology; Animals; Animals, Wild/*physiology; Atlantic Islands; Estrogens/analysis; Feces/chemistry; Female; Fertilization; Gestational Age; Horse Diseases/*epidemiology; Horses; Incidence; Pregnancy; *Pregnancy, Animal  
  Abstract Field observations of 400 totally unmanaged feral horses on Sable Island, Nova Scotia, were complemented by oestrogen determinations in faecal samples from 154 identified females over a 4-year period (454 mare-years). Of mares that were sampled throughout the year and subsequently produced foals, 92.1% exhibited elevated faecal oestrogens between 15 October and 30 March. The results confirm that faecal oestrogens are a useful indicator of pregnancy after approximately 120 days gestation. Distribution of foaling resembled that seen in other feral populations, with 95% of births occurring from April through July. The foaling rate for mares aged 3 years or older was 62.0%, with 50.7% of mares foaling in 3 or 4 years. Foaling rates were low (4.1%) in mares bred as yearlings and rose with age to 70.8% in those bred as 4-year-olds. Fetal loss after Day 120 was deduced from faecal oestrogens to be 26.0% overall, with marked variation from year to year (9.6-37.3%) and with age (70.0% in those bred as yearlings, decreasing to 5.6% in those bred as 4-year-olds). Of 58 mares aged 2 years or older that were sampled every year, about half (49.6%) the barren years were attributable to fetal loss after 120 days gestation. All mares conceived in at least 2 of the 4 years, suggesting that pregnancy loss, even after Day 120, is as important as failure to conceive in causing barren years.  
  Address Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Canada  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0449-3087 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1795292 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2247  
Permanent link to this record
 

 
Author Real, L.A. openurl 
  Title Animal choice behavior and the evolution of cognitive architecture Type Journal Article
  Year (up) 1991 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume 253 Issue 5023 Pages 980-986  
  Keywords Animals; Bees/genetics/*physiology; Biomechanics; *Choice Behavior; *Cognition; *Evolution; Mathematics; Models, Genetic; Probability  
  Abstract Animals process sensory information according to specific computational rules and, subsequently, form representations of their environments that form the basis for decisions and choices. The specific computational rules used by organisms will often be evolutionarily adaptive by generating higher probabilities of survival, reproduction, and resource acquisition. Experiments with enclosed colonies of bumblebees constrained to foraging on artificial flowers suggest that the bumblebee's cognitive architecture is designed to efficiently exploit floral resources from spatially structured environments given limits on memory and the neuronal processing of information. A non-linear relationship between the biomechanics of nectar extraction and rates of net energetic gain by individual bees may account for sensitivities to both the arithmetic mean and variance in reward distributions in flowers. Heuristic rules that lead to efficient resource exploitation may also lead to subjective misperception of likelihoods. Subjective probability formation may then be viewed as a problem in pattern recognition subject to specific sampling schemes and memory constraints.  
  Address Department of Biology, University of North Carolina, Chapel Hill 27599-3280  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-8075 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1887231 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2846  
Permanent link to this record
 

 
Author Kirkpatrick, J.F.; Liu, I.M.; Turner, J.W.J.; Naugle, R.; Keiper, R. openurl 
  Title Long-term effects of porcine zonae pellucidae immunocontraception on ovarian function in feral horses (Equus caballus) Type Journal Article
  Year (up) 1992 Publication Journal of reproduction and fertility Abbreviated Journal J Reprod Fertil  
  Volume 94 Issue 2 Pages 437-444  
  Keywords Animals; Contraception, Immunologic/*veterinary; *Egg Proteins; Estrogens, Conjugated (USP)/urine; Female; Glycoproteins/*pharmacology; Horses/immunology/*physiology; *Membrane Glycoproteins; Ovary/drug effects/*physiology; Progesterone/metabolism; *Receptors, Cell Surface; Swine/immunology; Time Factors; Zona Pellucida/*immunology  
  Abstract Ten feral mares free-roaming in Maryland, USA, were inoculated with porcine zonae pellucidae (PZP) protein before the breeding season for three consecutive years (1988-90). Ovarian function was monitored for 51 days during the peak of the breeding season after the third annual PZP inoculation, in seven of these mares and in four untreated control mares, by means of urinary oestrone conjugates and nonspecific progesterone metabolites. None of the ten inoculated mares became pregnant in 1990, compared with 55% of 20 control mares, which included two of the four monitored for ovarian function. Three of the untreated mares demonstrated apparent normal ovarian activity, characterized by preovulatory oestrogen peaks, concurrent progesterone nadirs at ovulation, breeding activity, and luteal-phase progesterone increases after ovulation. Two of the seven monitored PZP-treated mares demonstrated ovulatory cycles that did not result in conception. One was pregnant as a result of conception in 1989 and demonstrated a normal, late-gestation, endocrine profile. The remaining four PZP-treated mares revealed no evidence of ovulation, and urinary oestrogen concentrations were significantly depressed. The experiments indicated that (i) a third consecutive annual PZP booster inoculation is greater than 90% effective in preventing pregnancies in mares and (ii) three consecutive years of PZP treatment may interfere with normal ovarian function as shown by markedly depressed oestrogen secretion.  
  Address Deaconess Research Institute, Billings, MT 59102  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4251 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1317449 Approved no  
  Call Number refbase @ user @ Serial 145  
Permanent link to this record
 

 
Author Harkins, J.D.; Kamerling, S.G.; Church, G. openurl 
  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  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 8750-7587 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1568979 Approved no  
  Call Number refbase @ user @ Serial 1947  
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Author Gutierrez Rincon, J.A.; Vives Turco, J.; Muro Martinez, I.; Casas Vaque, I. openurl 
  Title A comparative study of the metabolic effort expended by horse riders during a jumping competition Type Journal Article
  Year (up) 1992 Publication British Journal of Sports Medicine Abbreviated Journal Br J Sports Med  
  Volume 26 Issue 1 Pages 33-35  
  Keywords Adult; Animals; Energy Metabolism/*physiology; *Exertion; Heart Rate/physiology; Horses; Humans; Lactates/blood; *Sports  
  Abstract The three main Olympic horse riding disciplines are dressage, jumping, and three-day eventing (including dressage, cross country and jumping). In the jumping discipline (obstacle race), the 'team' (horse rider) is judged under the different conditions that might take place in a varied run. The horse is expected to show power and ability; the rider must show riding skill and good physical condition. However, the different conditions encountered by the rider during competition (duration of event, continuous isometric working level, especially in the inferior trunk, lead us to consider the need for a rider to develop different metabolic pathways to meet the high energy requirements of the competition.  
  Address Centre de Medicina de l'Esport de Barcelona, Spain  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0306-3674 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1600451 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3754  
Permanent link to this record
 

 
Author Ratzlaff, M.H.; Wilson, P.D.; Hyde, M.L.; Balch, O.K.; Grant, B.D. openurl 
  Title Relationship between locomotor forces, hoof position and joint motion during the support phase of the stride of galloping horses Type Journal Article
  Year (up) 1993 Publication Acta Anatomica Abbreviated Journal Acta Anat (Basel)  
  Volume 146 Issue 2-3 Pages 200-204  
  Keywords Animals; Equipment Design; Hoof and Claw/*physiology; Horses/*physiology; Joints/*physiology; *Locomotion; Motor Activity/*physiology; Physiology/instrumentation; *Posture; Shoes; Transducers  
  Abstract Three methods were used simultaneously to determine the relationships between the vertical forces exerted on the hooves and the positions of the limbs and hooves at the times of peak vertical forces from 2 horses galloping on a track straightaway. Vertical forces were recorded from an instrumented shoe, fetlock joint motion was measured with an electrogoniometer and the angles of the carpus, fetlock and hoof were determined from slow-motion films. At hoof contact, the mean angles of the carpus and fetlock were 181-182 degrees and 199-206 degrees, respectively. Peak vertical forces on the heel occurred at or near maximum extension of the carpal and fetlock joints. Peak forces on the toe occurred during flexion of the fetlock joint and at mean hoof angles of 28-31 degrees from the horizontal. The mean angles of the hoof from the horizontal at the time of heel contact were 6-7 degrees. Hoof lift occurred at mean carpal angles of 173-174 degrees and mean fetlock angles of 199-200 degrees.  
  Address Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, College of Veterinary Medicine, Washington State University, Pullman 99164-6520  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-5180 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:8470468 Approved no  
  Call Number refbase @ user @ Serial 1945  
Permanent link to this record
 

 
Author Colahan, P.; Lindsey, E.; Nunier, C. openurl 
  Title Determination of the center of pressure of the hoofs of the forelimbs of horses standing on a flat level surface Type Journal Article
  Year (up) 1993 Publication Acta Anatomica Abbreviated Journal Acta Anat (Basel)  
  Volume 146 Issue 2-3 Pages 175-178  
  Keywords Animals; Forelimb/*physiology; Hoof and Claw/*physiology; Horses/*physiology; *Posture; Pressure  
  Abstract The pressure exerted on a flat level surface by recently trimmed, unshod hoofs of the front limbs of 23 sound, adult horses was measured using pressure-sensitive film and a specially built cassette. The horses were tranquilized and stood with one foot on the 2.9-cm-thick cassette and the other on a block of equal height. The hoofs were observed for motion during the measurement, and the developed film was examined for improper alignment of the film or slipping of the hoof. The center of pressure was located using the method of weighted proportions of Barrey. This static measurement system with a long measurement time and the number of measurements reduced the influence of variables inherent in the horses' behavior and the measuring system. The calculated point was recorded as falling medial to, lateral to or on a line bisecting the central sulcus of the frog. In the dorsal to palmar orientation the point was classified with reference to a line drawn halfway between the most dorsal and the most palmar mark on the film. Forty-six percent of the calculated centers of pressure were located in the medial heel area. Binomial analysis for large samples indicates that this was a significant variation from a random distribution. Seventy-six percent of the centers were located in or on the borders of the medial heel.  
  Address College of Veterinary Medicine, University of Florida, Gainesville 32608-0136  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-5180 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:8470462 Approved no  
  Call Number refbase @ user @ Serial 1946  
Permanent link to this record
 

 
Author Mellor, P.S. openurl 
  Title African horse sickness: transmission and epidemiology Type Journal Article
  Year (up) 1993 Publication Veterinary Research Abbreviated Journal Vet Res  
  Volume 24 Issue 2 Pages 199-212  
  Keywords Africa, Northern/epidemiology; African Horse Sickness/epidemiology/*transmission; African horse sickness virus/*physiology; Animals; Arachnid Vectors/microbiology; Ceratopogonidae/*microbiology; Culicidae/microbiology; Horses; Insect Vectors/*microbiology; Portugal/epidemiology; Spain/epidemiology; Ticks/microbiology  
  Abstract African horse sickness (AHS) virus causes a non-contagious, infectious, arthropod-borne disease of equines and occasionally of dogs. The virus is widely distributed across sub-Saharan African where it is transmitted between susceptible vertebrate hosts by the vectors. These are usually considered to be species of Culicoides biting midges but mosquitoes and/or ticks may also be involved to a greater or lesser extent. Periodically the virus makes excursions beyond its sub-Saharan enzootic zones but until recently does not appear to have been able to maintain itself outside these areas for more than 2-3 consecutive years at most. This is probably due to a number of factors including the apparent absence of a long term vertebrate reservoir, the prevalence and seasonal incidence of the vectors and the efficiency of control measures (vaccination and vector abatement). The recent AHS epizootics in Iberia and N Africa spanning as they do, 5 or more yr, seem to have established a new pattern in AHS virus persistence. This is probably linked to the continuous presence of adult C imicola in the area. Culicoides imicola is basically an Afro-Asiatic insect and prefers warm climates. Therefore its continuous adult presence in parts of Iberia and N Africa may be due to some recent moderations of the climate in these areas.  
  Address Institute for Animal Health, Pirbright Laboratory, Woking, Surrey, UK  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0928-4249 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:8102076 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2359  
Permanent link to this record
 

 
Author Clayton, H.M. openurl 
  Title Development of conditioning programs for dressage horses based on time-motion analysis of competitions Type Journal Article
  Year (up) 1993 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol  
  Volume 74 Issue 5 Pages 2325-2329  
  Keywords Animals; Horses/*physiology; *Physical Conditioning, Animal; *Sports; Statistics; Time Factors; *Time and Motion Studies; Videotape Recording  
  Abstract The time-motion characteristics of Canadian basic- and medium-level dressage competitions are described, and the results are applied in formulating sport-specific conditioning programs. One competition was analyzed at the six levels from basic 1 to medium 3. Each test was divided into a series of sequences based on the type and speed of activity. The durations of the sequences were measured from videotapes. The basic-level tests had fewer sequences, and they were shorter in distance and duration than the medium tests (P < 0.10), but the average speed did not differ between the two levels. It is recommended that horses competing at the basic levels be conditioned using 5-min exercise periods, with short (10-s) bursts of lengthened trot and canter included at basic 2 and above. In preparation for medium-level competitions, the duration of the work periods increases to 7 min, 10- to 12-s bursts of medium or extended trot and canter are included, and transitions are performed frequently to simulate the energy expenditure in overcoming inertia.  
  Address Department of Veterinary Anatomy, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 8750-7587 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:8335563 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3750  
Permanent link to this record
 

 
Author Clayton, H.M. openurl 
  Title The extended canter: a comparison of some kinematic variables in horses trained for dressage and for racing Type Journal Article
  Year (up) 1993 Publication Acta Anatomica Abbreviated Journal Acta Anat (Basel)  
  Volume 146 Issue 2-3 Pages 183-187  
  Keywords Animal Husbandry; Animals; *Gait; Horses/*physiology; *Physical Conditioning, Animal; *Sports  
  Abstract This study was designed to test the hypothesis that there is no significant difference in selected temporal and linear stride variables of the extended canter in horses bred and trained for dressage or racing. Nine advanced-level dressage horses and 7 Thoroughbred racehorses were filmed at a frame rate of 200 Hz at an extended canter on a sand track. Two strides were recorded per trial, and each horse performed 6 or 7 trials. Temporal and linear data were determined from the films, and descriptive statistics (mean, SD) were calculated. Strides were selected for analysis on the basis of having a velocity in the range of 6.0-7.0 m/s, and multivariate analysis of variance was used to detect significant differences in the stride kinematics of horses trained for the two sports (p < or = 0.01). The average velocity of the dressage horses was 6.37 m/s, compared with 6.40 m/s for the racehorses. There were no significant differences between the two groups in velocity, stride duration, stride length or the distances between limb placements. The stance durations of all four limbs and the overlaps between them were longer, whereas the duration of the suspension phase was shorter in the dressage horses than in the racehorses (p < or = 0.01). The time between impacts of the diagonal limb pair was close to zero in both groups, with individual horses showing some variability in the order of placement of the diagonal limb pair. However, the sequence of footfalls was not significantly different between the two groups (p < or = 0.01).  
  Address Department of Veterinary Anatomy, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-5180 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:8470464 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3751  
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