The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its spec... more The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its specific parameters as a new approach to assess stress load in cattle. We recorded HRV in 52 calves in three groups and in 31 cows in two groups. In calves we divided Group 1 with no obvious stress load (n=18), Group 2 with external stress load (n=17), and Group 3 with internal stress load from sickness (n=17). In cattle we divided lactating cows (n=21) and nonlactating cows (n=10). HRV parameters were analyzed in the time domain and in the frequency domain. Moreover, we applied Recurrence Quantification Analysis (RQA) to quantify nonlinear components of HRV. In calves, linear HRV parameter decreased from Group 1 to Group 3 (P<.05). However, not a single parameter showed significant differences regarding all three groups. The value of all nonlinear measurements increased at the same time (P<.05). The only parameter that exhibited significant differences between all three groups was the longest diagonal line segment in the recurrence plot (LMAX) which is inversely related to the Lyapunov exponent. We did not find differences concerning the linear HRV parameters between the two groups in the cows. The nonlinear parameter Determinism showed significant higher values in lactating cows compared to nonlactating cows. The importance of particular HRV-parameters was tested by applying a discriminant analysis approach. In calves and cattle nonlinear parameters were most important to indicate the level of stress load on the animals. Based on the results we assume HRV to be a valuable physiological indicator for stress load in animals. Whereas linear parameters of HRV are supposed to be useful to separate qualitative different level of stress, nonlinear components of HRV distinguish quantitative different challenges for the animals.
Using a portable ECG data logger, heart rate variability (HRV) in horses was measured under contr... more Using a portable ECG data logger, heart rate variability (HRV) in horses was measured under controlled- (resting-), mental stress- and physical stress conditions. Time domain-, frequency domain- and non-linear parameters were used to describe the variations in the HRV. Simple linear parameters like SDANN and RMSSD can demonstrate that there are differences in HRV between resting conditions, mental- and physical-stress conditions but do not give an explanation about the underlying mechanisms. Fourier analysis with calculation of low and high frequency bands gives further information: physical stress is characterised by an increase in sympathetic tone and a decrease in parasympathet ic tone - a fact which is commonly accepted. No differences could be found between resting conditions and mental stress. Summarising the results of non-linear recurrence plot variables, it seems, that during different physiological states the organism shifts between various control strategies. Under restin...
Monitoring training by measuring blood lactate content is a well-known procedure in sports physio... more Monitoring training by measuring blood lactate content is a well-known procedure in sports physiology. Because of the difficulties in standardizing a test procedure in field studies, this method is fraught with considerable problems when applying it to race horses. The aim of the present study was to develop a test procedure which is able to give evidence about the training state of different race horses after nonidentical test-loads. Under almost identical environmental conditions, the level of blood lactate was determined in five trotters which were kept in training. Immediately after the single phases of a three-stage test procedure (handicap: 'small', 'medium' and 'high' load for the animals chosen at the discretion of the coach) blood samples were drawn. The lactate value was set in relation to the speed of each animal. A curve of the equation y = y0 + e(k + b*x) was fitted with r2 > 0.93 to these data. With the aid of this equation, the 'comparat...
Berliner und Münchener tierärztliche Wochenschrift
The influence of social rank and social environment on visual discrimination learning of small gr... more The influence of social rank and social environment on visual discrimination learning of small groups of Nigerian dwarf goats (Capra hircus, n = 79) was studied using a computer-controlled learning device integrated in the animals' home pen. The experiment was divided into three sections (LE1, LE1 u, LE2; each 14d). In LE1 the goats learned a discrimination task in a socially stable environment. In LE1u animals were mixed and relocated to another pen and given the same task as in LE1. In LE2 the animals were mixed and relocated again and given a new discrimination task. We used drinking water as a primary reinforcer. The rank category of the goats were analysed as alpha, omega or middle ranking for each section of the experiment. The rank category had an influence on daily learning success (percentage of successful trials per day) only in LE1 u. Daily learning success decreased after mixing and relocation of the animals in LE1 u and LE2 compared to LE1. That resulted in an under...
Until the age of about 2 years, trotters normally grow up on pasture without any kind of training... more Until the age of about 2 years, trotters normally grow up on pasture without any kind of training. In the stud farm Lindenhof (Templin, Germany), however, these first 2 years are used for a special fitness training for the young animals: 2-3 times a week, a group of the yearlings is forced to run a distance of about 1700 m on a track at an average speed of up to 10 m/s. Until now, little was known about changes of blood parameters which may occur during such special exercise. This study therefore investigated the activity of selected serum enzymes (aspartate-amino-transferase (AST), alanine-amino-transferase (ALT), gamma-glutamyl-transferase (gamma-GT), lactic dehydrogenase (LDH), alkaline phosphatase (AP), creatine kinase (CK)) and the variations of hematocrit, hemoglobin, lactate, protein, and urea concentration before and after exercise. Except for activity of AP and CK and concentration of urea, all parameters showed a distinct increase after exercise. In particular, the rise in...
To determine the influence of various feeding schedules (different times of feeding, times withou... more To determine the influence of various feeding schedules (different times of feeding, times without feeding) on the time course of heart rate (HR), electric activity of cervical muscles (EMG), motor activity (ACT) and body temperature (TB) in ruminants, 5 sheep were equipped with portable dataloggers able to register and store these variables every 30s. Under controlled housing conditions, the temporal changes which occur were registered for 12 consecutive days each period at least. During experimental periods with various feeding times HR and TB were within the physiological range and all variables showed pronounced peaks which were associated with the time of food presentation. On days without feeding TB (38.8 degrees C) was at the lower limit of this range and HR (56 bpm) was extremely below this limit; similar peaks as before were not detectable. The circadian rhythms of HR and TB seemed not to be influenced by the different times of feeding, but there were hints, that photic or ...
Variations of core-temperature rhythms occurring during a "normal" day (24-hour period ... more Variations of core-temperature rhythms occurring during a "normal" day (24-hour period without extraordinary challenges for organism) were studied in 5 male sheep. To record the influence of the metabolic processes in different organic systems, core temperatures were measured at various locations at the same time. To minimise any influences due to measurement or behavior (e.g., effects of isolation), a telemetric system was used for registration and animals were kept without restraint in their habitual herd. Particularly biphasic circadian rhythms were found, and feeding schedule as zeitgeber is discussed. Beyond that, independent from point of measurement short-time rhythms with wavelengths of 140 and 90 min were found. Therefore, an origin in the central nervous system can be supposed. Rhythms with wavelengths of 3 hours, 75 min and 1 hour were not stable throughout a whole 24-hour period and did not occur at all measurement points in the same intensity. A comparison of ...
A postoperative (p.op.) estimation of "healthiness"--especially an estimation of durati... more A postoperative (p.op.) estimation of "healthiness"--especially an estimation of duration of possible existing changes, caused by surgical treatment--is important not only for the ongoing of the healing up process. A re-activation of treated farm or laboratory animals which is set up too early might produce reduction of efficiency or falsification of experimental results. Investigations on p.op. de-synchronisation have proved that "healthiness" means--besides the absence of clinical symptoms--also stable relations among the circadian rhythms. As the ultradian rhythms (wavelength less than 24 h) which exist beside the circadian ones depend on endogenic and exogenic factors much more than the circadian rhythms do, the aim of this study was to investigate strength and especially duration of changes p.op. in using core temperature rhythms of sheep as example, by setting great value on investigating ultradian rhythms. The core temperatures of 5 Merino-mixed sheep were...
ABSTRACT Strain-by-exercise Variations in the Activities of Selected Serumenzymes and the Blood C... more ABSTRACT Strain-by-exercise Variations in the Activities of Selected Serumenzymes and the Blood Concentrations of I actate and Hemoglobine in Young TrottersUntil the age of about 2 years, trotters normally grow up on pasture without any kind of training. In the stud farm Lindenhof (Templin, Germany), however, these first 2 years are used for a special fitness training for the young animals: 2–3 times a week, a group of the yearlings is forced to run a distance of about 1700 m on a track at an average speed of up to 10 m/s. Until now, little was known about changes of blood parameters which may occur during such special exercise. This study therefore investigated the activity of selected serumenzymes (aspartat-amino-transferase (AST), alanin-amino-transferase (ALT), γ-glutamyl-transferase (γ-GT), lactic dehydrogenase (LDH), alkaline phosphatase (AP), creatine kinase (CK)) and the variations of hematocrit, hemoglobin, lactate, protein, and urea concentration before and after exercise.Except for activity of AP and CK and concentration of urea, all parameters showed a distinct increase after exercise. In particular, the rise in lactic-acid concentration with values up to 23.08 mmol/l was remarkable, however, none of the parameters reached a pathological level. It is therefore concluded that exercise for young trotters over a medium distance–-even at high speed–-does not cause any injury of myocard, skeletal muscles or livercells.ZusammenfassungZusammenfassend ist zu sagen, daß es bei den untersuchten Parametern mit wenigen Ausnahmen (AP und CK beim Maitermin, Harnstoff) zwar durch die Belastung zu Erhöhungen der Aktivitäten bzw. Konzentrationen gekommen ist, daß sich die Belastungswerte jedoch in keinem Falle in einen Bereich erstrecken, der als pathologisch anzusehen ist. Trainingsläufe mit hoher Geschwindigkeit über mittlere Distanzen bewirken bei Trabern im Jährlingsalter somit ausgeprägte Lactacidosen; Schädigungen von Herz- und Skelettmuskulatur sowie von Leberzellen sind bei gesunden Tieren jedoch nicht zu befürchten.
During training, in 10 trotters, blood samples from the vena jugularis were taken before and afte... more During training, in 10 trotters, blood samples from the vena jugularis were taken before and after a heat with 80% of maximum capability as well as in the recovery period. Lactic acid concentration and pH-value, haematocrit and haemoglobin content, as well as protein concentration and osmolality were measured. With the exception of protein concentration, the time course of the values during the recovery could be described by simple mathematical models (biexponential or exponential equations). Only in the case of blood lactate concentration, the basal value was not yet achieved 120 min after the end of exercise. In the case of the other examined parameters, the homeostasis was restored earlier. Therefore, it seems to be recommendable when performing tests with preliminary heats and finals on the same day to stick to a break of at least 2 h between two races.
The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its spec... more The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its specific parameters as a new approach to assess stress load in cattle. We recorded HRV in 52 calves in three groups and in 31 cows in two groups. In calves we divided Group 1 with no obvious stress load (n=18), Group 2 with external stress load (n=17), and Group 3 with internal stress load from sickness (n=17). In cattle we divided lactating cows (n=21) and nonlactating cows (n=10). HRV parameters were analyzed in the time domain and in the frequency domain. Moreover, we applied Recurrence Quantification Analysis (RQA) to quantify nonlinear components of HRV. In calves, linear HRV parameter decreased from Group 1 to Group 3 (P<.05). However, not a single parameter showed significant differences regarding all three groups. The value of all nonlinear measurements increased at the same time (P<.05). The only parameter that exhibited significant differences between all three groups was the longest diagonal line segment in the recurrence plot (LMAX) which is inversely related to the Lyapunov exponent. We did not find differences concerning the linear HRV parameters between the two groups in the cows. The nonlinear parameter Determinism showed significant higher values in lactating cows compared to nonlactating cows. The importance of particular HRV-parameters was tested by applying a discriminant analysis approach. In calves and cattle nonlinear parameters were most important to indicate the level of stress load on the animals. Based on the results we assume HRV to be a valuable physiological indicator for stress load in animals. Whereas linear parameters of HRV are supposed to be useful to separate qualitative different level of stress, nonlinear components of HRV distinguish quantitative different challenges for the animals.
The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its spec... more The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its specific parameters as a new approach to assess stress load in cattle. We recorded HRV in 52 calves in three groups and in 31 cows in two groups. In calves we divided Group 1 with no obvious stress load (n=18), Group 2 with external stress load (n=17), and Group 3 with internal stress load from sickness (n=17). In cattle we divided lactating cows (n=21) and nonlactating cows (n=10). HRV parameters were analyzed in the time domain and in the frequency domain. Moreover, we applied Recurrence Quantification Analysis (RQA) to quantify nonlinear components of HRV. In calves, linear HRV parameter decreased from Group 1 to Group 3 (P<.05). However, not a single parameter showed significant differences regarding all three groups. The value of all nonlinear measurements increased at the same time (P<.05). The only parameter that exhibited significant differences between all three groups was the longest diagonal line segment in the recurrence plot (LMAX) which is inversely related to the Lyapunov exponent. We did not find differences concerning the linear HRV parameters between the two groups in the cows. The nonlinear parameter Determinism showed significant higher values in lactating cows compared to nonlactating cows. The importance of particular HRV-parameters was tested by applying a discriminant analysis approach. In calves and cattle nonlinear parameters were most important to indicate the level of stress load on the animals. Based on the results we assume HRV to be a valuable physiological indicator for stress load in animals. Whereas linear parameters of HRV are supposed to be useful to separate qualitative different level of stress, nonlinear components of HRV distinguish quantitative different challenges for the animals.
Using a portable ECG data logger, heart rate variability (HRV) in horses was measured under contr... more Using a portable ECG data logger, heart rate variability (HRV) in horses was measured under controlled- (resting-), mental stress- and physical stress conditions. Time domain-, frequency domain- and non-linear parameters were used to describe the variations in the HRV. Simple linear parameters like SDANN and RMSSD can demonstrate that there are differences in HRV between resting conditions, mental- and physical-stress conditions but do not give an explanation about the underlying mechanisms. Fourier analysis with calculation of low and high frequency bands gives further information: physical stress is characterised by an increase in sympathetic tone and a decrease in parasympathet ic tone - a fact which is commonly accepted. No differences could be found between resting conditions and mental stress. Summarising the results of non-linear recurrence plot variables, it seems, that during different physiological states the organism shifts between various control strategies. Under restin...
Monitoring training by measuring blood lactate content is a well-known procedure in sports physio... more Monitoring training by measuring blood lactate content is a well-known procedure in sports physiology. Because of the difficulties in standardizing a test procedure in field studies, this method is fraught with considerable problems when applying it to race horses. The aim of the present study was to develop a test procedure which is able to give evidence about the training state of different race horses after nonidentical test-loads. Under almost identical environmental conditions, the level of blood lactate was determined in five trotters which were kept in training. Immediately after the single phases of a three-stage test procedure (handicap: 'small', 'medium' and 'high' load for the animals chosen at the discretion of the coach) blood samples were drawn. The lactate value was set in relation to the speed of each animal. A curve of the equation y = y0 + e(k + b*x) was fitted with r2 > 0.93 to these data. With the aid of this equation, the 'comparat...
Berliner und Münchener tierärztliche Wochenschrift
The influence of social rank and social environment on visual discrimination learning of small gr... more The influence of social rank and social environment on visual discrimination learning of small groups of Nigerian dwarf goats (Capra hircus, n = 79) was studied using a computer-controlled learning device integrated in the animals' home pen. The experiment was divided into three sections (LE1, LE1 u, LE2; each 14d). In LE1 the goats learned a discrimination task in a socially stable environment. In LE1u animals were mixed and relocated to another pen and given the same task as in LE1. In LE2 the animals were mixed and relocated again and given a new discrimination task. We used drinking water as a primary reinforcer. The rank category of the goats were analysed as alpha, omega or middle ranking for each section of the experiment. The rank category had an influence on daily learning success (percentage of successful trials per day) only in LE1 u. Daily learning success decreased after mixing and relocation of the animals in LE1 u and LE2 compared to LE1. That resulted in an under...
Until the age of about 2 years, trotters normally grow up on pasture without any kind of training... more Until the age of about 2 years, trotters normally grow up on pasture without any kind of training. In the stud farm Lindenhof (Templin, Germany), however, these first 2 years are used for a special fitness training for the young animals: 2-3 times a week, a group of the yearlings is forced to run a distance of about 1700 m on a track at an average speed of up to 10 m/s. Until now, little was known about changes of blood parameters which may occur during such special exercise. This study therefore investigated the activity of selected serum enzymes (aspartate-amino-transferase (AST), alanine-amino-transferase (ALT), gamma-glutamyl-transferase (gamma-GT), lactic dehydrogenase (LDH), alkaline phosphatase (AP), creatine kinase (CK)) and the variations of hematocrit, hemoglobin, lactate, protein, and urea concentration before and after exercise. Except for activity of AP and CK and concentration of urea, all parameters showed a distinct increase after exercise. In particular, the rise in...
To determine the influence of various feeding schedules (different times of feeding, times withou... more To determine the influence of various feeding schedules (different times of feeding, times without feeding) on the time course of heart rate (HR), electric activity of cervical muscles (EMG), motor activity (ACT) and body temperature (TB) in ruminants, 5 sheep were equipped with portable dataloggers able to register and store these variables every 30s. Under controlled housing conditions, the temporal changes which occur were registered for 12 consecutive days each period at least. During experimental periods with various feeding times HR and TB were within the physiological range and all variables showed pronounced peaks which were associated with the time of food presentation. On days without feeding TB (38.8 degrees C) was at the lower limit of this range and HR (56 bpm) was extremely below this limit; similar peaks as before were not detectable. The circadian rhythms of HR and TB seemed not to be influenced by the different times of feeding, but there were hints, that photic or ...
Variations of core-temperature rhythms occurring during a "normal" day (24-hour period ... more Variations of core-temperature rhythms occurring during a "normal" day (24-hour period without extraordinary challenges for organism) were studied in 5 male sheep. To record the influence of the metabolic processes in different organic systems, core temperatures were measured at various locations at the same time. To minimise any influences due to measurement or behavior (e.g., effects of isolation), a telemetric system was used for registration and animals were kept without restraint in their habitual herd. Particularly biphasic circadian rhythms were found, and feeding schedule as zeitgeber is discussed. Beyond that, independent from point of measurement short-time rhythms with wavelengths of 140 and 90 min were found. Therefore, an origin in the central nervous system can be supposed. Rhythms with wavelengths of 3 hours, 75 min and 1 hour were not stable throughout a whole 24-hour period and did not occur at all measurement points in the same intensity. A comparison of ...
A postoperative (p.op.) estimation of "healthiness"--especially an estimation of durati... more A postoperative (p.op.) estimation of "healthiness"--especially an estimation of duration of possible existing changes, caused by surgical treatment--is important not only for the ongoing of the healing up process. A re-activation of treated farm or laboratory animals which is set up too early might produce reduction of efficiency or falsification of experimental results. Investigations on p.op. de-synchronisation have proved that "healthiness" means--besides the absence of clinical symptoms--also stable relations among the circadian rhythms. As the ultradian rhythms (wavelength less than 24 h) which exist beside the circadian ones depend on endogenic and exogenic factors much more than the circadian rhythms do, the aim of this study was to investigate strength and especially duration of changes p.op. in using core temperature rhythms of sheep as example, by setting great value on investigating ultradian rhythms. The core temperatures of 5 Merino-mixed sheep were...
ABSTRACT Strain-by-exercise Variations in the Activities of Selected Serumenzymes and the Blood C... more ABSTRACT Strain-by-exercise Variations in the Activities of Selected Serumenzymes and the Blood Concentrations of I actate and Hemoglobine in Young TrottersUntil the age of about 2 years, trotters normally grow up on pasture without any kind of training. In the stud farm Lindenhof (Templin, Germany), however, these first 2 years are used for a special fitness training for the young animals: 2–3 times a week, a group of the yearlings is forced to run a distance of about 1700 m on a track at an average speed of up to 10 m/s. Until now, little was known about changes of blood parameters which may occur during such special exercise. This study therefore investigated the activity of selected serumenzymes (aspartat-amino-transferase (AST), alanin-amino-transferase (ALT), γ-glutamyl-transferase (γ-GT), lactic dehydrogenase (LDH), alkaline phosphatase (AP), creatine kinase (CK)) and the variations of hematocrit, hemoglobin, lactate, protein, and urea concentration before and after exercise.Except for activity of AP and CK and concentration of urea, all parameters showed a distinct increase after exercise. In particular, the rise in lactic-acid concentration with values up to 23.08 mmol/l was remarkable, however, none of the parameters reached a pathological level. It is therefore concluded that exercise for young trotters over a medium distance–-even at high speed–-does not cause any injury of myocard, skeletal muscles or livercells.ZusammenfassungZusammenfassend ist zu sagen, daß es bei den untersuchten Parametern mit wenigen Ausnahmen (AP und CK beim Maitermin, Harnstoff) zwar durch die Belastung zu Erhöhungen der Aktivitäten bzw. Konzentrationen gekommen ist, daß sich die Belastungswerte jedoch in keinem Falle in einen Bereich erstrecken, der als pathologisch anzusehen ist. Trainingsläufe mit hoher Geschwindigkeit über mittlere Distanzen bewirken bei Trabern im Jährlingsalter somit ausgeprägte Lactacidosen; Schädigungen von Herz- und Skelettmuskulatur sowie von Leberzellen sind bei gesunden Tieren jedoch nicht zu befürchten.
During training, in 10 trotters, blood samples from the vena jugularis were taken before and afte... more During training, in 10 trotters, blood samples from the vena jugularis were taken before and after a heat with 80% of maximum capability as well as in the recovery period. Lactic acid concentration and pH-value, haematocrit and haemoglobin content, as well as protein concentration and osmolality were measured. With the exception of protein concentration, the time course of the values during the recovery could be described by simple mathematical models (biexponential or exponential equations). Only in the case of blood lactate concentration, the basal value was not yet achieved 120 min after the end of exercise. In the case of the other examined parameters, the homeostasis was restored earlier. Therefore, it seems to be recommendable when performing tests with preliminary heats and finals on the same day to stick to a break of at least 2 h between two races.
The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its spec... more The aim of this study was to evaluate the usefulness of heart rate variability (HRV) and its specific parameters as a new approach to assess stress load in cattle. We recorded HRV in 52 calves in three groups and in 31 cows in two groups. In calves we divided Group 1 with no obvious stress load (n=18), Group 2 with external stress load (n=17), and Group 3 with internal stress load from sickness (n=17). In cattle we divided lactating cows (n=21) and nonlactating cows (n=10). HRV parameters were analyzed in the time domain and in the frequency domain. Moreover, we applied Recurrence Quantification Analysis (RQA) to quantify nonlinear components of HRV. In calves, linear HRV parameter decreased from Group 1 to Group 3 (P<.05). However, not a single parameter showed significant differences regarding all three groups. The value of all nonlinear measurements increased at the same time (P<.05). The only parameter that exhibited significant differences between all three groups was the longest diagonal line segment in the recurrence plot (LMAX) which is inversely related to the Lyapunov exponent. We did not find differences concerning the linear HRV parameters between the two groups in the cows. The nonlinear parameter Determinism showed significant higher values in lactating cows compared to nonlactating cows. The importance of particular HRV-parameters was tested by applying a discriminant analysis approach. In calves and cattle nonlinear parameters were most important to indicate the level of stress load on the animals. Based on the results we assume HRV to be a valuable physiological indicator for stress load in animals. Whereas linear parameters of HRV are supposed to be useful to separate qualitative different level of stress, nonlinear components of HRV distinguish quantitative different challenges for the animals.
Uploads
Papers by Elmar Mohr