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Author Labruna, M.B.; Amaku, M. doi  openurl
  Title Rhythm of engorgement and detachment of Anocentor nitens females feeding on horses Type Journal Article
  Year 2006 Publication Veterinary Parasitology Abbreviated Journal Vet Parasitol  
  Volume (up) 137 Issue 3-4 Pages 316-332  
  Keywords Animals; Bites and Stings; Feeding Behavior; Female; Horses/*parasitology; Ixodidae/*physiology; Seasons; Tick Infestations/parasitology/*veterinary; Time Factors  
  Abstract The present study evaluated the engorgement and drop-off rhythms of Anocentor nitens females feeding on horses. Drop-off rhythm was evaluated at 6h-intervals (06:00, 12:00, 18:00, and 00:00 h) on horses held in stalls or in a pasture. A new method of marking feeding female ticks (the bowknot technique) was developed to evaluate ticks on horses in pasture that attached to different parts of the horse's body. This technique was highly successful, indicating no significant interference on tick engorgement rate or final tick weight, length and reproductive capability. Horses held in the pasture during the summer produced only 28.2% of the tick detachment during the daylight period from 06:00 to 18:00 h. In contrast, 53.4% of the ticks detached during this same 12 h-period during the winter. This difference was probably related to the longer scotoperiod during the winter. Different drop-off rhythms were observed for females attached to different anatomical parts of the horse's body. For example, ticks attached to the ears, perineum, and tail showed similar drop-off patterns, but were different from ticks attached to mane, rump and other body parts. The idiosoma length of the feeding female ticks was individually measured every 6 h until the engorged female detached naturally. The engorgement rate (increase in millimeters of the body length per hour) was evaluated during the last 96 h of parasitism. The highest engorgement rates were observed during the last 24 h of parasitism (approximately 0.16 mm/h), which were four-fold higher than the engorgement rates of the previous 3 days ( approximately 0.04 mm/h), demonstrating that these lower and higher values corresponded to the slow and rapid feeding phases reported elsewhere. Based on these data, the 6 mm idiosoma length was estimated as the minimal length that would correspond to the time point (i.e. 24 h before detachment) during which ticks would undergo the rapid feeding phase and detach as fully engorged females. When this 6 mm length was tested to estimate the number of engorged females detaching from horses in a period of 24 h, the estimated accuracy varied from 58.5 to 97.7% (mean: 73.3%).  
  Address Departamento de Medicina Veterinaria Preventiva e Saude Animal, Faculdade de Medicina Veterinaria e Zootecnia, Universidade de Sao Paulo, Av. Prof. Orlando Marques de Paiva, 87, Cidade Universitaria, Sao Paulo, SP 05508-000, Brazil. labruna@usp.br  
  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 0304-4017 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16481114 Approved no  
  Call Number Serial 1877  
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Author Piccione, G.; Caola, G.; Refinetti, R. doi  openurl
  Title Temporal relationships of 21 physiological variables in horse and sheep Type Journal Article
  Year 2005 Publication Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology Abbreviated Journal Comp Biochem Physiol A Mol Integr Physiol  
  Volume (up) 142 Issue 4 Pages 389-396  
  Keywords Animals; Behavior, Animal/physiology; Blood Glucose/physiology; Body Temperature/*physiology; Circadian Rhythm/*physiology; Female; Horses/*physiology; Melatonin/blood/*physiology; Motor Activity/*physiology; Rectum/physiology; Sheep/*physiology; Time Factors  
  Abstract Daily or circadian oscillation has been documented in a variety of physiological and behavioral processes. Although individual variables have been studied in great detail, very few studies have been conducted on the temporal relationships between the rhythms of different variables. It is not known whether the circadian pacemaker generates each and every rhythm individually or whether most rhythms are simply derived from a few clock-controlled rhythms. As a first step in elucidating this issue, 21 physiological variables were recorded simultaneously in horse and sheep. The results indicated that, in both species, different variables exhibit different degrees of daily rhythmicity and reach their daily peaks at different times of the day. The variables exhibiting strongest rhythmicity were locomotor activity, rectal temperature, and plasma concentrations of melatonin and glucose. Comparison of rhythmicity and acrophase in the various rhythms allowed inferences to be made about mechanisms of causation.  
  Address Dipartimento di Morfologia, Biochimica, Fisiologia e Produzioni Animali, Facolta di Medicina Veterinaria, Universita degli Studi di Messina, 98168 Messina, Italy  
  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 1095-6433 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16290083 Approved no  
  Call Number Serial 1884  
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Author Rapin, V.; Poncet, P.A.; Burger, D.; Mermod, C.; Richard, M.A. doi  openurl
  Title [Measurement of the attention time in the horse] Type Journal Article
  Year 2007 Publication Schweizer Archiv fur Tierheilkunde Abbreviated Journal Schweiz Arch Tierheilkd  
  Volume (up) 149 Issue 2 Pages 77-83  
  Keywords Age Factors; Animals; *Attention/physiology; Conditioning, Operant; Cross-Over Studies; Female; Horses/*physiology; Learning/*physiology; Male; Memory/*physiology; Time Factors  
  Abstract A study carried out on 49 horses showed that it is possible to measure the attention time by operant conditioning. After teaching horses an instrumental task using a signal, we were then able to test their attention time by asking them to prolong it increasingly while setting success and failure criteria. Two tests were performed 3 weeks apart. The 2nd test was feasible without relearning, a proof of memory, and was repeatable, a proof of consistency in the attention time. A significant difference was observed between the 3 age groups. Young horses often performed very well during the 1st test but their attention dropped in the 2nd test while older horses were more stable with respect to attention and even increased it slightly. The study shows that there are individual differences but it was not possible to prove a significant influence of breed, gender and paternal influence. Consequently, learning appears to be one of the most interesting approaches for evaluating the attention of horses and for observing their behaviour.  
  Address Laboratoire d'Ecoethologie, Universite de Neuchatel, Suisse. veronique.rapin@unine.ch  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language French Summary Language Original Title Mesure de la duree d'attention chez le cheval  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-7281 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17343134 Approved no  
  Call Number Serial 1770  
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Author Hinde, R.A. openurl 
  Title Analyzing the roles of the partners in a behavioral interaction--mother-infant relations in rhesus macaques Type Journal Article
  Year 1969 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci  
  Volume (up) 159 Issue 3 Pages 651-667  
  Keywords Age Factors; Animals; *Behavior, Animal; Female; Group Processes; Haplorhini; Leadership; Maternal Deprivation; *Mother-Child Relations; *Role; Time Factors  
  Abstract  
  Address  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0077-8923 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:4981882 Approved no  
  Call Number Serial 2054  
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Author Hodgson, D.; Howe, S.; Jeffcott, L.; Reid, S.; Mellor, D.; Higgins, A. doi  openurl
  Title Effect of prolonged use of altrenogest on behaviour in mares Type
  Year 2005 Publication Veterinary journal (London, England : 1997) Abbreviated Journal Vet J  
  Volume (up) 169 Issue 1 Pages 113-115  
  Keywords Administration, Oral; Anabolic Agents/adverse effects/*pharmacology; Animals; Behavior, Animal/*drug effects; Body Constitution/drug effects; Body Weight/drug effects; *Doping in Sports; Female; Horses/*physiology; Social Behavior; Social Dominance; Time Factors; Trenbolone/adverse effects/*analogs & derivatives/*pharmacology  
  Abstract Erratum in:

Vet J. 2005 May;169(3):321.

Corrected and republished in:

Vet J. 2005 May;169(3):322-5.

Oral administration of altrenogest for oestrus suppression in competition horses is believed to be widespread in some equestrian disciplines, and can be administered continuously for several months during a competition season. To examine whether altrenogest has any anabolic or other potential performance enhancing properties that may give a horse an unfair advantage, we examined the effect of oral altrenogest (0.044 mg/kg), given daily for a period of eight weeks, on social hierarchy, activity budget, body-mass and body condition score of 12 sedentary mares. We concluded that prolonged oral administration of altrenogest at recommended dose rates to sedentary mares resulted in no effect on dominance hierarchies, body mass or condition score.
 
  Address Faculty of Veterinary Science, University of Sydney, Private Mailbag 4, Narellan Delivery Centre, Narellan, NSW 2567, Australia. davidh@camden.usyd.edu.au  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1090-0233 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15683772 Approved no  
  Call Number refbase @ user @ Serial 671  
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Author Witte, T.H.; Knill, K.; Wilson, A.M. doi  openurl
  Title Determination of peak vertical ground reaction force from duty factor in the horse (Equus caballus) Type Journal Article
  Year 2004 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume (up) 207 Issue Pt 21 Pages 3639-3648  
  Keywords *Acceleration; Animals; Biomechanics; Forelimb/physiology; *Gait; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Telemetry; Time Factors  
  Abstract Measurement of peak vertical ground reaction force (GRFz) from multiple limbs simultaneously during high-speed, over-ground locomotion would enhance our understanding of the locomotor mechanics of cursorial animals. Here, we evaluate the accuracy of predicting peak GRFz from duty factor (the proportion of the stride for which the limb is in contact with the ground). Foot-mounted uniaxial accelerometers, combined with UHF FM telemetry, are shown to be practical and accurate for the field measurement of stride timing variables, including duty factor. Direct comparison with the force plate produces a mean error of 2.3 ms and 3.5 ms for the timing of foot on and foot off, respectively, across all gaits. Predictions of peak GRFz from duty factor show mean errors (with positive values indicating an overestimate) of 0.8+/-0.04 N kg(-1) (13%; N=42; mean +/- S.E.M.) at walk, -0.3+/-0.06 N kg(-1) (3%; N=75) at trot, -2.3+/-0.27 N kg(-1) (16%; N=18) for the non-lead limb at canter and +2.1+/-0.7 N kg(-1) (19%; N=9) for the lead limb at canter. The substantial over- and underestimate seen at canter, in the lead and non-lead limbs, respectively, is attributed to the different functions performed by the two limbs in the asymmetrical gaits. The difference in load experienced by the lead and non-lead limbs decreased with increasing speed.  
  Address Structure and Motion Lab, The Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, 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 0022-0949 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15371472 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3658  
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Author Bobbert, M.F.; Santamaria, S. doi  openurl
  Title Contribution of the forelimbs and hindlimbs of the horse to mechanical energy changes in jumping Type Journal Article
  Year 2005 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume (up) 208 Issue 2 Pages 249-260  
  Keywords Animals; Biomechanics; Forelimb/*physiology; Hindlimb/*physiology; Horses/*physiology; Locomotion/*physiology; Muscle, Skeletal/*physiology; Time Factors  
  Abstract The purpose of the present study was to gain more insight into the contribution of the forelimbs and hindlimbs of the horse to energy changes during the push-off for a jump. For this purpose, we collected kinematic data at 240 Hz from 23 5-year-old Warmbloods (average mass: 595 kg) performing free jumps over a 1.15 m high fence. From these data, we calculated the changes in mechanical energy and the changes in limb length and joint angles. The force carried by the forelimbs and the amount of energy stored was estimated from the distance between elbow and hoof, assuming that this part of the leg behaved as a linear spring. During the forelimb push, the total energy first decreased by 3.2 J kg(-1) and then increased again by 4.2 J kg(-1) to the end of the forelimb push. At the end of the forelimb push, the kinetic energy due to horizontal velocity of the centre of mass was 1.6 J kg(-1) less than at the start, while the effective energy (energy contributing to jump height) was 2.3 J kg(-1) greater. It was investigated to what extent these changes could involve passive spring-like behaviour of the forelimbs. The amount of energy stored and re-utilized in the distal tendons during the forelimb push was estimated to be on average 0.4 J kg(-1) in the trailing forelimb and 0.23 J kg(-1) in the leading forelimb. This means that a considerable amount of energy was first dissipated and subsequently regenerated by muscles, with triceps brachii probably being the most important contributor. During the hindlimb push, the muscles of the leg were primarily producing energy. The total increase in energy was 2.5 J kg(-1) and the peak power output amounted to 71 W kg(-1).  
  Address Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, van der Boechorstraat 9, NL-1081 BT Amsterdam, The Netherlands. MFBobbert@fbw.vu.nl  
  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 0022-0949 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15634844 Approved no  
  Call Number Serial 1895  
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Author Cameron, E.Z. doi  openurl
  Title Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism Type Journal Article
  Year 2004 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume (up) 271 Issue 1549 Pages 1723-1728  
  Keywords Age Factors; Animals; Body Constitution; *Evolution; Female; Glucose/metabolism/physiology; Litter Size; Male; Mammals/*physiology; *Models, Biological; Reproduction/physiology; Seasons; Sex Factors; *Sex Ratio; Time Factors  
  Abstract Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios.  
  Address Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15306293 Approved no  
  Call Number refbase @ user @ Serial 413  
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Author Gavrilova, O.; Haluzik, M.; Matsusue, K.; Cutson, J.J.; Johnson, L.; Dietz, K.R.; Nicol, C.J.; Vinson, C.; Gonzalez, F.J.; Reitman, M.L. doi  openurl
  Title Liver peroxisome proliferator-activated receptor gamma contributes to hepatic steatosis, triglyceride clearance, and regulation of body fat mass Type Journal Article
  Year 2003 Publication The Journal of biological chemistry Abbreviated Journal J Biol Chem  
  Volume (up) 278 Issue 36 Pages 34268-34276  
  Keywords Adipose Tissue/*metabolism; Animals; Blotting, Southern; Blotting, Western; Female; Hypoglycemia/genetics; Insulin Resistance/genetics; Lipid Metabolism; Liver/*metabolism; Liver Diseases/genetics/*metabolism; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; RNA/metabolism; Receptors, Cytoplasmic and Nuclear/*genetics/*physiology; Recombination, Genetic; Thiazoles/pharmacology; *Thiazolidinediones; Time Factors; Transcription Factors/*genetics/*physiology; Triglycerides/*metabolism  
  Abstract Peroxisome proliferator-activated receptor gamma (PPAR gamma) is a nuclear receptor that mediates the antidiabetic effects of thiazolidinediones. PPAR gamma is present in adipose tissue and becomes elevated in fatty livers, but the roles of specific tissues in thiazolidinedione actions are unclear. We studied the function of liver PPAR gamma in both lipoatrophic A-ZIP/F-1 (AZIP) and wild type mice. In AZIP mice, ablation of liver PPAR gamma reduced the hepatic steatosis but worsened the hyperlipidemia, triglyceride clearance, and muscle insulin resistance. Inactivation of AZIP liver PPAR gamma also abolished the hypoglycemic and hypolipidemic effects of rosiglitazone, demonstrating that, in the absence of adipose tissue, the liver is a primary and major site of thiazolidinedione action. In contrast, rosiglitazone remained effective in non-lipoatrophic mice lacking liver PPAR gamma, suggesting that adipose tissue is the major site of thiazolidinedione action in typical mice with adipose tissue. Interestingly, mice without liver PPAR gamma, but with adipose tissue, developed relative fat intolerance, increased adiposity, hyperlipidemia, and insulin resistance. Thus, liver PPAR gamma regulates triglyceride homeostasis, contributing to hepatic steatosis, but protecting other tissues from triglyceride accumulation and insulin resistance.  
  Address Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. oksanag@bdg10.niddk.nih.gov  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9258 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12805374 Approved no  
  Call Number refbase @ user @ Serial 81  
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Author Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A. url  doi
openurl 
  Title Spontaneous emergence of leaders and followers in foraging pairs Type Journal Article
  Year 2003 Publication Nature Abbreviated Journal Nature  
  Volume (up) 423 Issue 6938 Pages 432-434  
  Keywords Animals; *Energy Metabolism; Food; *Food Chain; *Models, Biological; Motor Activity; *Social Behavior; Time Factors  
  Abstract Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. s.rands@zoo.cam.ac.uk  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12761547 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5138  
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