Graf Lehndorff Institute for Equine Sciences


Graf Lehndorff Institute for Equine Sciences

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Nagel C.,Graf Lehndorff Institute for Equine Sciences | Nagel C.,University of Vienna | Aurich J.,Section for Obstetrics | Aurich C.,Graf Lehndorff Institute for Equine Sciences | Aurich C.,University of Vienna
Theriogenology | Year: 2010

Heart rate is an important parameter of fetal well-being. We have analyzed fetal heart rate (HR) and heart rate variability (HRV) by fetomaternal electrocardiography (ECG) in the horse (Equus caballus) from midpregnancy to foaling. It was the aim of the study to detect changes in the regulation of fetal cardiac activity over time and to establish normal values in undisturbed pregnancies. A total of 22 mares were available for the study. Fetomaternal electrocardiography was a reliable technique to detect cardiac signals in fetuses between Day 173 of gestation and foaling. Fetal HR decreased from 115 ± 4 beats/min (Days 170 to 240 of gestation) to 83 ± 3 beats/min (Day 320) to 79 ± 1 beats/min (1 d before foaling; P < 0.001). Mean beat to beat (RR) interval and standard deviation of the RR interval (SDRR) increased (P < 0.001). Gestational age thus affects RR interval and HR in the equine fetus. From Days 270 to 340 of gestation, SDRR increased from 11.4 ± 1.3 msec on Day 270 to 27.8 ± 3.6 msec on Day 340 (P < 0.05), and the root mean square of successive RR differences (RMSSD) tended to increase (P = 0.07), indicating maturation of the fetal autonomous nervous system. For the last 10 d before foaling, fetal HR and HRV remained constant and did not allow predicting the onset of parturition in the horse. Only during the last 30 min before the foal was born, in 4 of 5 fetuses, HR decreased and RR interval increased. Accelerations and decelerations in HR were detectable at all times, but neither their number nor duration changed over time. © 2010 Elsevier Inc. All rights reserved.

Rojer H.,University of Vienna | Aurich C.,Graf Lehndorff Institute for Equine Sciences
Reproduction in Domestic Animals | Year: 2010

Contents: Recently, successful treatment of mares with a history of persistent mating-induced endometritis (PMIE) with dexamethasone has been reported. As systemic treatment of horses with glucocorticoids should be handled with caution, we tested the hypothesis that treatment with the non-steroid anti-inflammatory drug (NSAID) vedaprofen, an inhibitor of cyclooxygenase-2, may have comparative, positive effects on fertility. Barren mares with a history of repeated PMIE were treated with vedaprofen (n = 8; initially 2 mg/kg bodyweight followed by 1 mg/kg orally twice daily) from 1 day before the first insemination to 1 day after ovulation or left untreated (n = 9). All mares received oxytocin (20 I.E. s.c.) thrice daily. Uterine swabs were collected for bacteriology and cytology. The day after ovulation, fluid accumulation was detected in three control mares and four treated mares (n.s.). The percentage of neutrophils in uterine cytology was significantly increased in comparison to the day before ovulation irrespective of treatment. Pregnancy was confirmed in two of nine mares in the control group and seven of eight mares in the treatment group (p < 0.05). NSAIDs may positively affect fertility in mares with a history of PMIE. © 2010 Blackwell Verlag GmbH.

Schmid-Lausigk Y.,Graf Lehndorff Institute for Equine Sciences | Aurich C.,University of Vienna
Theriogenology | Year: 2014

Seasonal changes in the reproductive physiology of stallions contribute to a decrease in the quality of frozen-thawed semen during late winter. Changes in the lipid composition of the sperm plasma membrane may contribute to this phenomenon. In the present study, we have, therefore, investigated the effects of adding linseed oil (LO) in combination with antioxidants to the diet of breeding stallions on the motility and membrane integrity of cooled-stored and cryopreserved semen. Starting in November, the diet of LO stallions (n = 6) but not control (C) stallions (n = 5) was supplemented with LO (100mL once daily) plus an antioxidant (Myostem Protect; Audevard, Clichy, France) for a total of 84days. Before (November) and at the end of this period (February), ejaculates were processed for cryopreservation (n = 3 ejaculates per stallion) and cooled shipping at 5 °C. Frozen-thawed and cooled-shipped semen was sent to the laboratory for computer-assisted semen analysis of total motility, progressive motility, and velocity parameters (average path velocity [VAP], curved line velocity [VCL], and straight-line velocity [VSL]) and evaluation of membrane integrity. The quality of frozen-thawed semen decreased (P < 0.05) from November (e.g., total motility LO 69 ± 3% and C 67 ± 3%) to February (total motility: LO 55 ± 4% and C 59 ± 3%) independent of treatment (P > 0.05). A decrease in the velocity parameters VAP, VCL, and VSL was more pronounced in LO stallions than in C stallions (e.g., VSL: November LO 67 ± 1μm/s, C 64 ± 2μm/s; February LO 59 ± 2μm/s, C 63 ± 2μm/s; interaction month by treatment, P < 0.05). In cooled-stored semen, total motility, progressive motility, and membrane integrity were lower in February than in November (P < 0.001 for all parameters). Supplementation of the diet with LO and antioxidants attenuated this decrease (e.g., Day 1 of cooled storage = 24 hours after semen collection: total motility in November LO 88 ± 1% and C 87 ± 3%; in February LO 83 ± 2% and C 73 ± 11%; interaction month by treatment: P < 0.05). Velocity parameters VAP, VCL, and VSL were significantly lower in February than in November (P < 0.001), but this decrease was not affected by treatment. In summary, dietary supplementation of stallions with LO plus antioxidants attenuated a decline in motility and membrane integrity of cooled-stored stallion semen during winter. This may improve the fertility of cooled-shipped semen. In contrast, the treatment did not counteract the decrease in quality of frozen-thawed semen that occurs in late winter. © 2014 Elsevier Inc.

Willmann C.,Graf Lehndorff Institute for Equine Sciences | Budik S.,University of Vienna | Walter I.,University of Vienna | Aurich C.,Graf Lehndorff Institute for Equine Sciences | Aurich C.,University of Vienna
Theriogenology | Year: 2011

A positive influence of altrenogest treatment on a retarded development of the conceptus around the beginning of placentation in mares older than 8 years could be recently demonstrated. In the present study, effects of altrenogest treatment in early-pregnant mares on conceptus development and expression of endometrial and embryonic genes were investigated. Genes were chosen according to a possible involvement in embryo-maternal interaction and embryonic development in the equine species. Mares were treated with altrenogest (0.044 mg/kg bodyweight) or sunflower oil (placebo) from day 5 to 11 after ovulation. Embryos (altrenogest n = 13, placebo n = 12) and biopsies were collected on day 11. Pregnancy rate and embryonic size were not influenced by treatment (embryonic diameter: altrenogest 7.0 ± 2.5, placebo 6.5 ± 1.7 mm, n.s.). The percentage of luminal epithelial cells, superficial glandular epithelial cells and interstitial cells with nuclei staining positively for the progesterone receptor was significantly lower (P < 0.05) in samples collected from altrenogest-treated than from placebo-treated mares (e.g., luminal epithelium: altrenogest 1.9 ± 1.7%, placebo 23.0 ± 10.5%, P < 0.05). Staining for COX2 (cyclooxygenase-2) was not affected by treatment. In the endometrium a slight but significant increase in the number of PMN (polymorph nuclear neutrophils) was seen in response to treatment (altrenogest 0.8 ± 0.5 PMN/field, placebo 0.3 ± 0.3 PMN/field; P < 0.05). No differences in the relative gene expression of COX2, the receptors for progesterone, estrogens and growth hormone as well as for IGF (insulin-like growth factor) 1 and 2 were detected. The relative gene expression of aquaporin 3 in relation to β-actin differed significantly (P < 0.05) between embryos from altrenogest (3.2 ± 0.8) and placebo-treated mares (1.3 ± 0.2), but no other genes were affected. The study demonstrates down-regulation of progesterone receptors in the endometrium of early pregnant mares by treatment with the progestin altrenogest. This increased expression of aquaporin 3 in the conceptus was not related to changes in embryonic size or development. © 2011 Elsevier Inc.

von Lewinski M.,Graf Lehndorff Institute for Equine Sciences | Biau S.,Institute Francais Du Cheval Et Of Lequitation | Erber R.,University of Vienna | Ille N.,University of Vienna | And 4 more authors.
Veterinary Journal | Year: 2013

Although some information exists on the stress response of horses in equestrian sports, the horse-rider team is much less well understood. In this study, salivary cortisol concentrations, heart rate (HR) and heart rate variability (HRV), SDRR (standard deviation of beat-to-beat interval) and RMSSD (root mean square of successive beat-to-beat intervals) were analysed in horses and their riders (n= 6 each) at a public performance and an identical rehearsal that was not open to the public. Cortisol concentrations increased in both horses and riders (P< 0.001) but did not differ between performance and rehearsal. HR in horses and riders increased during the rehearsal and the public performance (P< 0.001) but the increase in HR was more pronounced (P< 0.01) in riders than in their horses during the public performance (from 91 ± 10 to 150 ± 15. beats/min) compared to the rehearsal (from 94 ± 10 to 118 ± 12. beats/min). The SDRR decreased significantly during the equestrian tasks in riders (P< 0.001), but not in their horses. The RMSSD decreased in horses and riders (P< 0.001) during rehearsal and performance, indicating a decrease in parasympathetic tone. The decrease in RMSSD in the riders was more pronounced (P< 0.05) during the performance (from 32.6 ± 6.6 to 3.8 ± 0.3. ms) than during the rehearsal (from 27.5 ± 4.2 to 6.6 ± 0.6. ms). The study has shown that the presence of spectators caused more pronounced changes in cardiac activity in the riders than it did in their horses. © 2013 Elsevier Ltd.

Schmidt A.,Graf Lehndorff Institute for Equine Sciences | Schmidt A.,University of Vienna | Aurich J.,University of Vienna | Mostl E.,University of Vienna | And 3 more authors.
Hormones and Behavior | Year: 2010

Based on cortisol release, a variety of situations to which domestic horses are exposed have been classified as stressors but studies on the stress during equestrian training are limited. In the present study, Warmblood stallions (n=9) and mares (n=7) were followed through a 9 respective 12-week initial training program in order to determine potentially stressful training steps. Salivary cortisol concentrations, beat-to-beat (RR) interval and heart rate variability (HRV) were determined. The HRV variables standard deviation of the RR interval (SDRR), RMSSD (root mean square of successive RR differences) and the geometric means standard deviation 1 (SD1) and 2 (SD2) were calculated. Nearly each training unit was associated with an increase in salivary cortisol concentrations (p<0.01). Cortisol release varied between training units and occasionally was more pronounced in mares than in stallions (p<0.05). The RR interval decreased slightly in response to lunging before mounting of the rider. A pronounced decrease occurred when the rider was mounting, but before the horse showed physical activity (p<0.001). The HRV variables SDRR, RMSSD and SD1 decreased in response to training and lowest values were reached during mounting of a rider (p<0.001). Thereafter RR interval and HRV variables increased again. In contrast, SD2 increased with the beginning of lunging (p<0.05) and no changes in response to mounting were detectable. In conclusion, initial training is a stressor for horses. The most pronounced reaction occurred in response to mounting by a rider, a situation resembling a potentially lethal threat under natural conditions. © 2010 Elsevier Inc.

Schmidt A.,Graf Lehndorff Institute for Equine Sciences | Mostl E.,University of Vienna | Wehnert C.,Graf Lehndorff Institute for Equine Sciences | Aurich J.,University of Vienna | And 3 more authors.
Hormones and Behavior | Year: 2010

Based on plasma cortisol concentrations it is widely accepted that transport is stressful to horses. So far, cortisol release during transport has not been evaluated in depth by non-invasive techniques such as analysis of salivary cortisol and faecal cortisol metabolites. Transport also causes changes in heart rate and heart rate variability (HRV). In this study, salivary cortisol, faecal cortisol metabolites, heart rate and HRV in horses transported by road for short (one and 3.5 h) and medium duration (8 h) were determined. With the onset of transport, salivary cortisol increased immediately but highest concentrations were measured towards the end of transport (4.1 ± 1.6, 4.5 ± 2.6, 6.5 ± 1.8 ng/ml in horses transported for one, 3.5 and 8 h, respectively). Faecal cortisol metabolite concentrations did not change during transport, but 1 day after transport for 3.5 and 8 h had increased significantly (p < 0.01), reflecting intestinal passage time. Compared to salivary cortisol, changes in faecal cortisol metabolites were less pronounced. Heart rate increased and beat-to-beat (RR) interval decreased (p < 0.05) with the onset of transport. Standard deviation of heart rate increased while root mean square of successive RR differences (RMSSD) decreased in horses transported for 3.5 (from 74 ± 5 to 45 ± 6 ms) and 8 h (from 89.7 ± 7 to 59 ± 7 ms), indicating a reduction in vagal tone. In conclusion, transport of horses over short and medium distances leads to increased cortisol release and changes in heart rate and HRV indicative of stress. The degree of these changes is related to the duration of transport. Salivary cortisol is a sensitive parameter to detect transient changes in cortisol release. © 2009 Elsevier Inc. All rights reserved.

Aurich C.,University of Vienna | Aurich C.,Graf Lehndorff Institute for Equine Sciences
Animal Reproduction Science | Year: 2011

Horses are long-day breeders. During the breeding season, cycle length is about 22 days with 5-7 days of oestrus. Gonadotroph cells are localized in the pars distalis as well the pars tuberalis of the pituitary and heterogeneity in the pattern of LH and FSH storage within the gonadotroph population is considered the basis for the differential regulation of gonadotrophin secretion throughout the reproductive cycle. No short and distinct periovulatory LH peak exists in the mare. The equine ovary has an extreme large size and weight. One to two major follicular waves develop per cycle. The preovulatory follicle reaches an average size of 40mm. Only granulosa cells develop into luteal cells. Progesterone increases at the time of ovulation and reaches maximal concentrations on day 8. Functional luteolysis occurs around day 15 and is initiated by endometrial secretion of PGF 2α. In contrast to other species, no significant luteal oxytocin synthesis exists in the mare. During the oestrous cycle, uterus, vagina and endometrium undergo pronounced changes related to variations in the endocrine milieu. Seasonal reproductive activity is stimulated by photoperiod together with exogenous factors. The anovulatory season can be differentiated into an autumn transitional phase, a mid-anovulatory period and a spring transitional phase bringing the mare back into cyclic activity. During the mid-anovulatory period, follicular development is minimal. The beginning of the spring transitional period is characterized by the development of 1-3 anovulatory follicular waves before ovulation occurs and the most important factor for the re-initiation of ovulatory activity is the occurrence of repeated pronounced increases in circulating LH. © 2011 Elsevier B.V.

Nagel C.,Graf Lehndorff Institute for Equine Sciences | Aurich J.,University of Vienna | Aurich C.,Graf Lehndorff Institute for Equine Sciences | Aurich C.,University of Vienna
Reproduction in Domestic Animals | Year: 2011

Abortion and preterm birth of foals are major reasons for reproductive losses in the horse. Risk pregnancies require close supervision so that adequate treatment can be initiated in time. The aim of this study was to determine normal values in heart rate (HR) and heart rate variability (HRV) of the pregnant mare compared to her foetus and to detect physiological changes during ongoing gestation. In mares, the RR interval decreased from 1480±29ms on day 270 of pregnancy to 1190±58ms on day 330 of pregnancy (p<0.05). In contrast, foetal RR interval increased during the same time period from 611±23ms on day 270 of gestation to 756±25ms on day 330 of gestation (p<0.05). Concomitantly, maternal HR increased and foetal HR decreased. No further changes in RR interval occurred during the last 10days before foaling, neither in the mare nor the foetus. In the last hours preceding parturition, maternal RR interval was lower than at all times earlier in pregnancy (average of 1037±13ms) but did not change during this time. Maternal HRV did not change during gestation. Marked changes in HRV occurred only during the last minutes of foaling. Then, all HRV variables increased significantly (standard deviation of beat-to-beat interval: p=0.01, root mean square of successive beat-to-beat differences: p<0.01). The cardiovascular system of pregnant mares adapted to the demands of ongoing pregnancy with an increase in HR. We have no evidence that in healthy mares, pregnancy is a major stressor. © 2011 Blackwell Verlag GmbH.

Pasing S.,Graf Lehndorff Institute for Equine Sciences | von Lewinski M.,Graf Lehndorff Institute for Equine Sciences | Wulf M.,Graf Lehndorff Institute for Equine Sciences | Erber R.,University of Vienna | Aurich C.,University of Vienna
Theriogenology | Year: 2013

The aim of this study was to evaluate the stress response of stallions (n = 16) aged 3-13 years with previous sexual experience to semen collection by determination of heart rate, heart rate variability, and cortisol in saliva. Recordings were done on two consecutive days. The time intervals from leaving the box until arrival in the collection barn and from first exposure to the teaser mare until ejaculation as well as the number of mounts until ejaculation were neither affected by collection day nor by age, sexual experience (i.e., the number of breeding seasons the stallion experienced), or sexual workload of the stallion (i.e., the mean number of semen collections per week). Heart rate was continuously determined from 30 minutes before to 30 minutes after ejaculation and significantly increased in response to the semen collection procedure (P < 0.001). Changes in heart ratewere significantly influenced by sexual experience (P < 0.01) and sexual workload (P< 0.05) but not by the age of the stallions. Day of semen collection did not have any effects. The heart rate variability variable root mean square of successive RR differences was not affected by semen collection procedures. Cortisol concentration in saliva was determined from 60 minutes before to 120 minutes after ejaculation and did not change significantly. The results indicate that semen collection is perceived as not more than a modest temporary stressor in sexually experienced and well-trained stallions. © 2013 Elsevier Inc.

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