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1.
OBJECTIVE: To determine heart rate (HR) and heart rate variability (HRV) after IV administration of 3 doses of atropine to clinically normal, large-breed adult dogs. ANIMALS: 6 mixed-breed dogs, weighing between 23 and 50 kg. PROCEDURE: Continuous ECG were recorded prior to and following IV administration of saline (0.9% NaCl) solution and 0.02, 0.04, and 0.06 mg of atropine/kg of body weight. Heart rate and HRV within sympathetic and parasympathetic domains were determined, using customized software, and responses to treatments were compared. Each dog received all treatments with > or = 2 days between treatments. RESULTS: HR increased and HRV within the parasympathetic domain decreased after all atropine treatments, compared with pretreatment values. Heart rate was significantly higher after administration of 0.06 mg of atropine/kg than after 0.02 mg/kg but was not different from HR after administration of 0.04 mg/kg. Five of 6 dogs given the 0.04 or 0.06 mg/kg dose attained HR > 135 beats/min, but only 1 of 6 dogs given the 0.02 mg/kg dose attained a HR > 135 beats/min. Heart rate variability within the parasympathetic domain decreased significantly from pretreatment values after all atropine treatments. Atropine doses of 0.04 and 0.06 mg/kg induced significantly lower HRV than did the 0.02 mg/kg dose, but HRV after the higher doses were not different from each other. HRV within the sympathetic domain after any treatment did not change from pretreatment values. CONCLUSIONS AND CLINICAL RELEVANCE: IV administration of 0.04 or 0.06 mg of atropine/kg increased HR and induced complete parasympathetic blockade in clinically normal, large-breed adult dogs.  相似文献   

2.
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±29 ms on day 270 of pregnancy to 1190±58 ms on day 330 of pregnancy (p<0.05). In contrast, foetal RR interval increased during the same time period from 611±23 ms on day 270 of gestation to 756±25 ms 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 10 days 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±13 ms) 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.  相似文献   

3.
The effects of hyoscine-N-butylbromide (hyoscine) and propantheline-bromide (propantheline) on heart rate (HR), HR variability (HRV) and gastrointestinal tract (GIT) contractions in the normal horse were determined. Five adult horses had ECG recordings for 180min after treatment with propantheline (100mg), hyoscine (120mg) or saline. Both propantheline and hyoscine reduced GIT sounds, with propantheline having a longer duration of effect (?120min). Both drugs elevated HR relative to the control baseline period (P<0.05), with the effects of propantheline again being of longer duration. HRV analysis indicated that propantheline suppressed Total Power (P<0.05), and both the high frequency (HF) and low frequency (LF) components of the power spectral analysis for up to 60-90min post treatment. Hyoscine had no effect on HRV Total Power but reduced the HF component for 30min after drug injection. Time domain variables correlated with Total Power and HF data (P<0.01). The marked effect of these compounds on parasympathetic control of cardiac and GIT function in normal horses should be taken into consideration when evaluating a clinical response to these agents.  相似文献   

4.
Heart rate (HR) and heart rate variability (HRV) are often determined with Polar heart rate monitors (HRMs; S810i; Polar, Kempele, Finland). The aims of this study were to compare data from horses obtained by Polar HRMs and a portable Televet electrocardiogram (ECG; 100 version 4.2.3; Kruuse, Marslev, Denmark) device and to determine appropriate recording times in horses (n = 14). Correlations were calculated and a Bland-Altman analysis was carried out to examine agreement between recording systems. For beat-to-beat (RR) interval, uncorrected and corrected data were highly correlated irrespective of the recording system and recording time (r > 0.99, P < 0.001). For HRV variables, standard deviation of RR interval and root mean square of successive RR intervals, correlations higher than 0.9 were obtained between uncorrected and corrected ECG but not Polar data. The RR interval, HR, and HRV from corrected Televet and Polar data at no time differed between the recording systems. However, with the increase in recording time, the RR interval decreased (P < 0.001). Thus, for comparisons, recording intervals of similar length should be chosen. Correlations among RR interval, HR, and HRV variables obtained by ECG and HRMs were highly significant at all recording times (r > 0.9, P < 0.001). Correlations increased with increasing recording time. Bland-Altman graphs showed a strong agreement between HRMs and ECG and mean RR intervals, HR, and HRV variables were close to identical. In conclusion, Polar HRMs are as adequate as ECG recordings in horses. Owing to a low HR in stationary horses, recording times below 2 minutes will underestimate changes in HR and HRV.  相似文献   

5.
The objective of this study was to assess the effect of relaxing massage on the heart rate (HR) and heart rate variability (HRV) in young racehorses during their first racing season. In the study, 72 Purebred Arabian racehorses were included. The study was implemented during the full race season. The horses from control and experimental groups were included in regular race training 6 days a week. The horses from the experimental group were additionally subject to the relaxing massage 3 days a week during the whole study. HR and HRV were assumed as indicators of the emotional state of the horses. The measurements were taken six times, every 4‐5 weeks. The HRV parameters were measured at rest, during grooming and saddling the horse and during warm‐up walking under a rider. The changes of the parameters throughout the season suggest that the relaxing massage may be effectively used to make the racehorses more relaxed and calm. Moreover, the horses from the experimental group had better race performance records.  相似文献   

6.
To investigate heart rate and its variability, a telemetry device was affixed to 16 healthy, young cats. Prior to inclusion in the study, cats were subject to echocardiographic examination. The heart rate (HR) when cats were restrained for echocardiography (HR(r)) was calculated from 4-5 consecutive RR intervals obtained from a simultaneously recorded electrocardiogram. Electrocardiographic data were then acquired by telemetry in a quiet room in the veterinary hospital (VTH) and later, in the owner's home (home). The ambulatory data were digitally sampled and the RR interval tachogram from a 4 min epoch subject to Fast Fourier Transform to yield measures of heart rate variability (HRV). Sinus arrhythmia was often observed in resting cats. Heart rates (bpm) expressed as mean (+/-SD) were: HRr: 187 (+/-25), HRVTH: 150 (+/-23), HR(home): 132 (+/-19); each of these rates was significantly different from the others. Significant differences in profiles of HRV suggested that sympathetic tone was higher (and parasympathetic tone lower) when cats were in the hospital.  相似文献   

7.
Analysis of heart rate (HR) and heart rate variability (HRV) are powerful tools to investigate cardiac diseases, but current methods, including 24-h Holter monitoring, can be cumbersome and may be compromised by movement artefact. A commercially available data capture and analysis system was used in anaesthetised healthy cats to measure HR and HRV during pharmacological manipulation of HR. Seven healthy cats were subjected to a randomised crossover study design with a 7 day washout period between two treatment groups, placebo and atenolol (1 mg/kg, IV), with the efficacy of atenolol to inhibit β1 adrenoreceptors challenged by epinephrine. Statistical significance for the epinephrine challenge was set at P < 0.0027 (Holm–Bonferroni correction), whereas a level of significance of P < 0.05 was set for other variables.Analysis of the continuous electrocardiography (ECG) recordings showed that epinephrine challenge increased HR in the placebo group (P = 0.0003) but not in the atenolol group. The change in HR was greater in the placebo group than in the atenolol group (P = 0.0004). Therefore, compared to cats pre-treated with placebo, pre-treatment with atenolol significantly antagonised the tachycardia while not significantly affecting HRV. The increased HR in the placebo group following epinephrine challenge was consistent with a shift of the sympathovagal balance towards a predominantly sympathetic tone. However, the small (but not significant at the critical value) decrease in the normalised high-frequency component (HFnorm) in both groups of cats suggested that epinephrine induced a parasympathetic withdrawal in addition to sympathetic enhancement (increased normalised low frequency component or LFnorm). In conclusion, this model is a highly sensitive and repeatable model to investigate HRV in anaesthetised cats that would be useful in the laboratory setting for short-term investigation of cardiovascular disease and subtle responses to pharmacological agents in this species.  相似文献   

8.
OBJECTIVE: To determine whether evaluation of heart rate (HR) and HR variability (HRV) during prolonged road transportation in horses provides a sensitive index of autonomic stimulation. ANIMALS: Five 2-year-old Thoroughbreds. PROCEDURE: ECGs were recorded as horses were transported for 21 hours in a 9-horse van. Heart rate, high-frequency (HF) power, low-frequency (LF) power, and LF-to-HF ratio from Fourier spectral analyses of ECGs were calculated and compared with values recorded during a 24-hour period of stall rest preceding transportation. RESULTS: HR, HF power, and LF power had diurnal rhythms during stall rest but not during road transportation. Heart rate was higher and HF power and LF power lower during road transportation than stall rest, and HR, HF power, LF power, and LF-to-HF ratio all decreased with time during road transportation. Heart rate during stall rest was weakly and inversely associated with LF power, but during road transportation was strongly associated with LF power, HF power, and LF-to-HF ratio. Neither LF power nor HF power was correlated with LF-to-HF ratio during stall rest, but LF power was strongly and HF power weakly correlated with LF-to-HF ratio during road transportation. High-frequency power and LF power were significantly correlated with each other during stall rest and road transportation. Heart rate was significantly influenced by LF power and LF-to-HF ratio during stall rest (R(2) = 0.40) and by HF power and LF-to-HF ratio during road transportation (R(2) = 0.86). CONCLUSIONS AND CLINICAL RELEVANCE: HR is influenced by different sympathovagal mechanisms during stall rest, compared with during road transportation; HRV may be a sensitive indicator of stress in transported horses.  相似文献   

9.
Background: Few reported studies describe normal values from 24‐hour ECG (Holter) recordings of small breed dogs. Objectives: To investigate influence of breed, age, sex, body weight, degree of recording artifact, and mitral valve prolapse (MVP) on Holter recordings of 3 breeds of small dogs that have differing predispositions for myxomatous mitral valve disease. The study also assessed if heart rate (HR) at clinical examination (HRex) was associated with HR during Holter monitoring and evaluated the reproducibility of Holter variables. Animals: Fifty clinically healthy, privately owned dogs of the breeds Cavalier King Charles Spaniel (CKCS), Wire‐haired Dachshund (wD), or Cairn Terrier (CT). Methods: Prospective, longitudinal observational study. Dogs were recruited for clinical examination, echocardiography, and Holter monitoring. In 8 CKCS, Holter recordings were performed twice with a 7‐day interval. Arrhythmia and heart rate variability (HRV) analysis (time and frequency domain analysis) were performed on Holter recordings. Results: Fifteen out of 27 Holter derived variables were significantly associated with breed (P < .03), but not with age (P > .7), sex (P > .2), body weight (P > .7), degree of recording artifact (P > .4), or MVP (P > .6). During Holter recording, minimum (P= .0001) and mean HR (P= .0001) were higher in CKCS compared with wD. CKCS had significantly lower values than wD, CT, or both in 10 out of 13 HRV variables (P < .03). Minimum and mean HR during Holter recording were correlated with HRex (r= 0.55, P= .0003). HR and time domain variables had a coefficient of variation <10%. Conclusions and Clinical Importance: There is an influence of breed on Holter‐derived variables in 3 breeds of small dogs. Arrhythmia and HRV analysis can be performed on 24‐hour ambulatory ECG (Holter) recordings. Arrhythmia analysis includes HR measurements and identification of arrhythmias.  相似文献   

10.
Cortisol is involved in the initiation of parturition and we hypothesized that increased maternal cortisol release advances the onset of foaling. Transport is a stressor for horses and induces an increase in cortisol release. To determine stress effects on the time of foaling, late-pregnant mares were transported by road for 3 hours (n = 12) or remained in their stable as controls (n = 4). Starting on day 325 of gestation, saliva and blood samples were taken for cortisol and progestin analysis, respectively. Fetomaternal electrocardiograms were recorded repeatedly. Mares were checked for impending parturition and changes in precolostrum pH. When pH decreased to 6.5, mares were either transported or left untreated. After birth, saliva was collected repeatedly from mares and their foals and heart rate (HR) was recorded. Foals were checked for maturity and health. Gestation length was 337 ± 2 days in stressed and 336 ± 2 days in control mares. Cortisol concentration increased from 3.3 ± 0.9 to 8.4 ± 0.8 ng/mL in transported mares (P < .001) and remained constant in controls. Maternal HR and heart rate variability (HRV) did not differ between groups and neither fetal HR nor HRV changed in response to transport. In transported mares, time from precolostrum decrease to parturition was shorter (40 ± 10 hours) than the respective time in controls (134 ± 49 hours, P < .01). Neither duration of foaling nor times to first standing and suckling of foals or the postnatum increase in HR and decrease in HRV differed between groups. In conclusion, transport-induced maternal cortisol release may have advanced the onset of foaling.  相似文献   

11.
The effects of hyoscine-N-butylbromide (hyoscine) and propantheline-bromide (propantheline) on heart rate (HR), HR variability (HRV) and gastrointestinal tract (GIT) contractions in the normal horse were determined. Five adult horses had ECG recordings for 180 min after treatment with propantheline (100 mg), hyoscine (120 mg) or saline. Both propantheline and hyoscine reduced GIT sounds, with propantheline having a longer duration of effect (⩾120 min). Both drugs elevated HR relative to the control baseline period (P < 0.05), with the effects of propantheline again being of longer duration. HRV analysis indicated that propantheline suppressed Total Power (P < 0.05), and both the high frequency (HF) and low frequency (LF) components of the power spectral analysis for up to 60–90 min post treatment. Hyoscine had no effect on HRV Total Power but reduced the HF component for 30 min after drug injection. Time domain variables correlated with Total Power and HF data (P < 0.01). The marked effect of these compounds on parasympathetic control of cardiac and GIT function in normal horses should be taken into consideration when evaluating a clinical response to these agents.  相似文献   

12.
Heart rate (HR), HR variability (HRV) and salivary cortisol concentrations were determined in foals (n = 13) during the perinatal phase and until 5 months of age. In the fetus, HR decreased from 77 ± 3 beats/min at 120 min before birth to 60 ± 1 beats/min at 5 min before birth (P <0.01). Within 30 min of birth, HR increased to 160 ± 9 beats/min (P <0.01). Salivary cortisol concentrations immediately after birth were 11.9 ± 3.6 ng/mL and within 2 h increased to a maximum of 52.5 ± 12.3 ng/mL (P <0.01). In conclusion, increases in HR and salivary cortisol concentrations in foals are not induced during parturition, but occur immediately after birth.  相似文献   

13.
A good horse-rider 'match' is important in the context of equine welfare. To quantify the influence of repetition and horse-rider matching on the stress of horses encountering challenging objects, 16 Warmblood horses were ridden in a test-setting on three occasions. On each occasion the horse was ridden by a different rider and was challenged by three objects (A-C). Heart rate (HR), heart rate variability (HRV) of horse and rider, and behaviour score (BS) of the horse were obtained for each object and as a total for each test. The horse-rider interaction was evaluated with each combination and assessed as 'matching' or 'mismatching', and the horses were categorised as 'compliant', 'partly-compliant' or 'non-compliant'. Horses exhibited a decreased HR (P=0.015) and a decreased BS (P=0.004) within and across different tests. 'Matching' horse-rider combinations exhibited less stress as indicated by reduced HR ('match' 69±10 vs. 'mismatch' 72±9, P=0.001) and BS ('match' 1.9±1.1 vs. 'mismatch' 3.8±1.4, P=0.017) of the horse. 'Compliant' (68±8, P<0.001) and 'partly-compliant' (71±9, P=0.002) horses had significantly lower HR than 'non-compliant' (75±9) animals. The findings of the study indicate that HR and BS measurements support a subjective 'match' diagnosis and HR measurement may be a valuable tool in assessing horse compliance.  相似文献   

14.
The pattern of variation in heart rate on a beat-to-beat basis contains information concerning sympathetic (SNS) and parasympathetic (PNS) contributions to autonomic nervous system (ANS) modulation of heart rate (HR). In the present study, heart period (RR interval) time series data were collected at rest and during 3 different treadmill exercise protocols from 6 Thoroughbred horses. Frequency and spectral power were determined in 3 frequency bands: very low (VLF) 0-< or = 0.01, low (LO) >0.01-< or = 0.07 and high (HI) >0.07-< or = 0.5 cycles/beat. Indicators of sympathetic (SNSI = LO/HI) and parasympathetic (PNSI = HI/TOTAL) activity were calculated. Power in all bands fell progressively with increasing exercise intensity from rest to trot. At the gallop VLF and LO power continued to fall but HI power rose. SNSI rose from rest to walk, then fell with increasing effort and was lowest at the gallop. PNSI fell from rest to walk, then rose and was highest at the gallop. Normalised HI power exceeded combined VLF and LO power at all gaits, with the ratio HI to LO power being lowest at the walk and highest at the gallop. ANS indicators showed considerable inter-horse variation, and varied less consistently than raw power with increasing physical effort. In the horses studied, the relationship between power and HR changed at exercise intensities associated with heart rates above approximately 120-130 beats/min. At this level, humoral and other non-neural mechanisms may become more important than autonomic modulation in influencing heart rate and heart rate variability (HRV). HRV at intense effort may be influenced by respiratory-gait entrainment, energetics of locomotion and work of breathing. HRV analysis in the frequency domain would appear to be of potential value as a noninvasive means of assessing autonomic modulation of heart rate at low exercise intensities, only. The technique may be a sensitive method for assessing exercise response to experimental manipulations and disease states.  相似文献   

15.
ObjectiveTo determine whether preoperative electrocardiographic measurements linked to sympathetic nervous activity could be used to predict recovery quality after general anaesthesia in horses.Study designProspective, clinical study.AnimalsEighteen adult client-owned horses.MethodsThe electrocardiogram (ECG) was recorded presurgery in horses under three standard conditions: stabled unattended; with a groom whilst being led along a standard course; alone in the induction box. After surgery, each animal's recovery quality was scored by eight experienced anaesthetists or technicians using Donaldson's scoring system (2000). The digitized ECG recordings were analyzed for T-wave morphology, mean heart rate (HR), HR variability (HRV) and HRV derivatives including mean R-R interval, standard deviation of normal intervals (SDNN) and the root mean square of successive intervals (RMSSD), low (LF) and high frequency (HF) activity and the LF/HF ratio in both fast Fourier transformed and autoregressive spectra. Correlations between ECG variables and recovery score were examined using Spearman's rank correlation.ResultsThere was no significant correlation between preanaesthetic ECG measurements and recovery quality.ConclusionsPredictions of recovery quality after general anaesthesia in horses cannot be based on preanaesthetic ECG variables.Clinical relevanceMeasures other than those based on the ECG should be investigated as predictors of recovery quality.  相似文献   

16.
One of the mechanisms by which acupuncture (AP) exerts its purported effects involves modulation of the autonomic nervous system. Heart rate variability (HRV) noninvasively and quantitatively assesses autonomic nervous system activity. We hypothesized that AP treatment would acutely affect HRV by affecting autonomic tone. Eleven horses received three treatments in random order on different days: AP, placement of AP needles at eight AP points; sham AP (SAP), placement of eight AP needles at non-AP points; and control, no needles inserted. A Holter monitor recorded an electrocardiogram for 40 minutes during each treatment session and was analyzed over three periods: 10 minutes of initial “baseline” before AP and/or SAP, the first 10 minutes of a 20-minute AP/SAP/control “treatment”, and the first 10 minutes “post”-AP/SAP/control. RR intervals were measured during each period after the electrocardiograms were inspected and filtered, and mean heart rate (HR), low-frequency (LF) power (0.01–0.07 Hz), high-frequency (HF) power (0.07–0.6 Hz), and LF-to-HF ratio were calculated for each period. Baseline HR decreased with sequential experiments. Within experiments, HF decreased and LF-to-HF ratio increased reciprocally with time. These results suggest that parasympathetic tone decreased over the course of the experiment, perhaps, because of the stress of being restrained. Consequently, HRV indices were either not acutely affected by AP over the intervals studied or autonomic responses to being restrained may have masked any autonomic response to AP.  相似文献   

17.
【Objective】 The objective of this study was to analyze the effect of different training stages on the performance and heart rate variability(HRV) of Yili horses and to provide data for reference in the conditioning training of 1 600 m distance Yili horses.【Method】 Eight 3-year-old Yili horses (stallions) were selected as test subjects.A 3-month speed specific performance training program was conducted, and a speed test race was organized in the last week of each month of training, and HRV was collected before, immediately after, 0.5 h after, and 1 h after 1 600 m test race.Among them, the time-domain indexes included the mean of all R-R intervals (Mean RR), the standard deviation of all R-R intervals (SDNN), the mean heart rate (Mean HR), the root mean square of the difference between adjacent R-R intervals (RMSSD), the number of adjacent R-R intervals with a difference greater than 50 ms (NN50), and the percentage of adjacent R-R intervals with a difference greater than 50 ms to the total number of heartbeats (pNN50).Frequency domain metrics included very low frequency (VLF), low frequency power (LF), high frequency power (HF) and nonlinear metrics:standard deviation (Y) of all R-R-spacing (SD1), standard deviation (X) of all R-R-spacing (SD2).Consequently, the variability of HRV indexes in horses at different training stages was analyzed.【Result】 The race time in the post training period in 1 600 m speed test race of Yili horses was significantly lower than that in the early training period (P<0.05), and Mean RR, NN50 and pNN50 in the middle and post training periods were significantly lower than that in the early training period (P<0.05).Mean HR in the beginning of training was significantly lower than that in post training (P<0.05).VLF and LF in the end of training were significantly lower than that in the beginning of training (P<0.05).【Conclusion】 Under the conditions of this test, the HRV indexes of 1 600 m test race of Yili horses in different conditioning training stages were analyzed.The outcomes demonstrated that the types of neural activity in Yili horses at the beginning, middle and end of training presented some differences, showing changes of increased sympathetic excitability and decreased parasympathetic excitability, and the horses' athletic performance improved.Therefore, HRV could be considered as an effective tool to evaluate the training load and intensity of Yili horses during training.  相似文献   

18.
【目的】研究流产伊犁马与正常分娩伊犁马在妊娠期心率变异性(HRV)的变化规律,以防止不良妊娠结局的发生。【方法】选取妊娠时间为29孕周的伊犁马21匹(其中流产5匹,正常分娩16匹)及7匹空怀伊犁马,分别在妊娠中期第30孕周,妊娠后期第45孕周及分娩前后1天对母马进行24 h HRV采集,包括时域指标:全部R-R间期的平均值(Mean RR)、全部R-R间距的标准差(SDNN)、平均心率(Mean HR)、相邻R-R间期差值的均方根(RMSSD)、相邻R-R间距差＞50 ms的个数(NN50)和相邻R-R-间距差＞50 ms的个数占总心跳次数的百分比(pNN50);频域指标:极低频率(VLF)、低频功率(LF)和高频功率(HF);非线性指标:全部R-R间距的标准差(Y)(SD1)、全部R-R间距的标准差(X)(SD2)。【结果】时域指标中,流产组和正常分娩组Mean RR、SDNN、RMSSD、NN50、pNN50极显著或显著低于空怀组(P＜0.01;P＜0.05),Mean HR极显著高于流产组和正常分娩组(P＜0.01);频域指标中,流产组和正常分娩组HF、LF极显著低于空怀组(P＜0.01),流产组和空怀组母马VLF极显著高于正常分娩组(P＜0.01)。非线性指标中,流产组和正常分娩组SD1和SD2极显著或显著低于空怀组(P＜0.01;P＜0.05),正常分娩组母马SD2/SD1极显著高于流产组和空怀组(P＜0.01)。【结论】伊犁马心率变异性在不同妊娠状态下均呈波动变化,Mean HR、Mean RR、SD2/SD1值在妊娠母马中出现上升,母马在妊娠过程中副交感神经占主导,自主神经系统受到抑制,流产母马VLF指标出现升高,在流产发生前后交感神经占主导,自主神经系统产生兴奋。  相似文献   

19.
Different head–neck positions (HNPs) are used in equestrian sports and are regarded as desirable for training and competition by riders, judges and trainers. Even though some studies have been indicative of hyperflexion having negative effects on horses, this unnatural position is frequently used. In the present study, the influence of different HNPs on physical and psychological stress parameters in the ridden horse was investigated. Heart rate (HR), heart rate variability (HRV) and blood cortisol levels were measured in 18 horses. Low frequency (LF) and high frequency (HF) are power components in the frequency domain measurement of HRV which show the activity of the sympathetic and parasympathetic nervous system. Values were recorded at rest, while riding with a working HNP and while riding with hyperflexion of the horse's head, neck and poll. In addition, rideability and behaviour during the different investigation stages were evaluated by the rider and by an observer. Neither the HR nor the HRV showed a significant difference between working HNP (HR = 105 ± 22/min; LF/HF = 3.89 ± 5.68; LF = 37.28 ± 10.77%) and hyperflexion (HR = 110 ± 18; LF/HF = 1.94 ± 2.21; LF = 38.39 ± 13.01%). Blood cortisol levels revealed a significant increase comparing working HNP (158 ± 60 nm ) and hyperflexion (176 ± 64 nm , p = 0.01). The evaluation of rider and observer resulted in clear changes of rideability and behavioural changes for the worse in all parameters collected between a working HNP and hyperflexion. In conclusion, changes of the cortisol blood level as a physical parameter led to the assumption that hyperflexion of head, neck and poll effects a stress reaction in the horse, and observation of the behaviour illustrates adverse effects on the well‐being of horses during hyperflexion.  相似文献   

20.
The goal of this study was to define the impact of colonization of gnotobiotic (Gn) pigs with lactic acid bacteria (LAB) on development of intestinal and systemic B cell responses to human rotavirus (HRV). The LAB-specific and total B cell responses were also assessed. Gn pigs were inoculated with LAB (Lactobacillus acidophilus and L. reuteri) and virulent Wa strain HRV (LAB+HRV+), HRV only (LAB-HRV+), LAB only (LAB+HRV-) or mock (LAB-HRV-). The HRV infection induced similar HRV-specific intestinal and systemic antibody and B cell responses in pigs with or without LAB, whereas LAB significantly enhanced total intestinal IgA secreting cell responses and total serum IgM and intestinal IgM and IgG titers. The LAB colonization did not reduce HRV shedding or diarrhea, this may be partly due to the short time interval between the first LAB feeding and HRV inoculation. Further studies are needed with longer time for LAB to establish before HRV inoculation. However, our studies demonstrate that Gn pigs infected with HRV develop a similar magnitude of virus-specific B cell responses as those of HRV-infected and LAB colonized pigs. LAB colonization alone is not as efficient in promoting intestinal B cell responses, as is HRV infection.  相似文献   

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