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Burger, D., Baumgartner, M., Schauer, S. N., Wägeli, S., Aurich, C., & Gerber, V. (2008). Influence of the recipient mare on character traits of adult offspring in a Warmblood embryo transfer program – preliminary results. In IESM 2008.
Abstract: The influence of recipient mares in commercial embryo transfer (ET) programs
on behavior of the ET foals is a matter of great interest and controversial discussion. Presently, no interdisciplinary ethological and reproductive studies on this topic exist. However, empirical experience suggests that behavioral traits of the recipient mare do not influence those of the foal, thus implying a predominantly genetic origin of a horse"s basic character. Aim: The aim of the present study was to investigate the influence of recipient mares on behavioural traits of their ET products. Materials and Methods: Based on records of the embryo transfer program in Warmblood horses since 1990 at the Swiss National Stud, questionnaires concerning behavior, stereotypies and mother-foal-relationship were designed and completed by telephone interview: 18 scientifically assessed questions provided the basis for a linear description (Equine Personality Assessment Questionnaire, Lloyd et al., 2007). They were grouped in a) emotivity, b) social motivation, c) general level of activity, d) stress behavior, e) learning capacity and f) reactions towards humans. Questionnaires were designed for the owners of the ET offspring (minimum of three years of age), the sires, donor mares and the recipient mares. Out of 200 questionnaires, 25 complete ET families have emerged so far and were analysed. All genetic parents were Warmblood horses, as were 23 of the recipient mares, the other two were Franches-Montagnes horses. Results: Comparing the mean values of the four groups (genetic dam and sire, recipient mare and ET product), significant differences were found for the parameters emotivity (sires lower, p<0.001), learning behaviour (recipient mares lower, p<0.05) and activity (recipient mares lower, p<0.05). With only one exception, the multiple variable regression analysis found no significant influence of the recipient mare on the ET product. The only significant effect observed, was that of the social motivation of the recipient mare on the learning capacity of the ET offspring (r2= -0.421, p<0.05). In contrast, numerous significant effects of behavioural traits of the genetic dams and sires on their ET offspring (10 and 8, respectively) were observed. Conclusions: These preliminary results confirm field observations that the influence of the recipient mare does not play an important role in character development of the ET offspring. However, the investigated parameters indicate that the behavioural traits of the genetic parents appear to have a strong influence on the offspring"s behaviour.. This study model promises new achievements in the evaluation of genetic and environmental effects on the behavior of a horse. References Lloyd, AS, Martin, JE, Bornett-Gauci, HLI, Wilkinson, RG (2007). Evaluation of a novel method of horse personality asses |
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Wehnert, C., Schmidt, A., Möstl, E., Aurich, J., Müller, J., & Aurich, C. (2008). Heart rate and cortisol release in horses during road transport. In IESM 2008.
Abstract: In sport horses, equestrian competitions may lead to increased cortisol release. The competition itself but also a new environment or transport to the events can be considered as stressors. In this study, warmblood sport horses (4-16 years, 4 mares, 2 stallions, 18 geldings) were transported by road for one (t1), 3.5 (t3.5) and 8 hours (t8), (n=8 per group). Heart rate (HR) is an indicator of stress and correlates with cortisol release. Heart rate was recorded with a mobile recording system (f810i, Polar, Kempele, Finland), fixed to a girth around the thorax of the horse and was monitored the day before transport, during transport and 12 hours thereafter. In addition, cortisol metabolite concentrations in faeces were determined in order to analyse adrenocortical activation during transport. Faecal samples were collected three times per day. Cortisol metabolite concentrations in faeces are increased approximately 24 hours after an elevation in plasma cortisol concentrations. Basal HR before transport did not differ between groups (45±2 (SEM) beats/min). During the first 30 min of transport, HR increased significantly (84±6, p<0.001, Kruskal-Wallis-H-test) but did not differ between groups. During the remaining part of the transport, HR was 61±6 beats/min (p<0.001 vs. first 30 min). When HR was analysed for the last 30 min of transport, values for groups t1 and t8 were significantly (p<0.05) higher than in group t3.5. HR decreased to baseline values within less than 30 min after transport and did not differ between groups (30-60 min after transport: 44±3 beats/min). Faecal cortisol metabolite concentrations on the day after transport were elevated compared to pre-transport baseline values in all three groups of horses. Significant differences existed between groups (e.g. 18 hours after transport t1: 91±5, t3.5: 110±18, t8: 136±27 ng/g; p<0.05). Based on HR analysis, horses of group t3.5 had adapted to transport, while the prolonged transport in group t8 again was a stressor. In group t1, which was transported only for one hour, the higher heart during the last 3 min of transport was still part of the initial rise in HR. After an initial increase, heart decreases indicating adaptation of the horse to transport. Cortisol metabolite concentrations in faeces indicate that transport causes adrenocortical activation with the amount of cortisol released depending on the duration of transport. Transport over medium distances appears to no major stressor and a negative impact on the performance of the horse is unlikely. Transport over 8 hours caused the most pronounced cortisol release and HR increases again during the last hours of an 8-hour transport. Transports exceeding this time may temporarily affect the subsequent performance of the horse in equestrian sports.
Supported by Stiftung Forschung für das Pferd |