Heart Rate Of Pigs Research Articles

Contactless Video-Based Heart Rate Monitoring of a Resting and an Anesthetized Pig.

Simple SummaryContactless physiological monitoring can be important for animal health and well-being. The current study investigated whether heart rate in pigs can be extracted automatically from videos without disturbing the pig and showed that this was possible with 4.69 beats per minute in mean absolute error. The study also tested different body regions and found that the abdomen was a better region to measure heart rate from videos compared to the front leg or the neck. However, future studies are needed that include videos with different light conditions, different housing systems and multiple pigs to enable real-time on-farm monitoring of heart rate from videos.Heart rate (HR) is a vital bio-signal that is relatively easy to monitor with contact sensors and is related to a living organism’s state of health, stress and well-being. The objective of this study was to develop an algorithm to extract HR (in beats per minute) of an anesthetized and a resting pig from raw video data as a first step towards continuous monitoring of health and welfare of pigs. Data were obtained from two experiments, wherein the pigs were video recorded whilst wearing an electrocardiography (ECG) monitoring system as gold standard (GS). In order to develop the algorithm, this study used a bandpass filter to remove noise. Then, a short-time Fourier transform (STFT) method was tested by evaluating different window sizes and window functions to accurately identify the HR. The resulting algorithm was first tested on videos of an anesthetized pig that maintained a relatively constant HR. The GS HR measurements for the anesthetized pig had a mean value of 71.76 bpm and standard deviation (SD) of 3.57 bpm. The developed algorithm had 2.33 bpm in mean absolute error (MAE), 3.09 bpm in root mean square error (RMSE) and 67% in HR estimation error below 3.5 bpm (PE3.5). The sensitivity of the algorithm was then tested on the video of a non-anaesthetized resting pig, as an animal in this state has more fluctuations in HR than an anaesthetized pig, while motion artefacts are still minimized due to resting. The GS HR measurements for the resting pig had a mean value of 161.43 bpm and SD of 10.11 bpm. The video-extracted HR showed a performance of 4.69 bpm in MAE, 6.43 bpm in RMSE and 57% in PE3.5. The results showed that HR monitoring using only the green channel of the video signal was better than using three color channels, which reduces computing complexity. By comparing different regions of interest (ROI), the region around the abdomen was found physiologically better than the face and front leg parts. In summary, the developed algorithm based on video data has potential to be used for contactless HR measurement and may be applied on resting pigs for real-time monitoring of their health and welfare status, which is of significant interest for veterinarians and farmers.

Cilostazol blocks pregnancy in naturally cycling swine: An animal model.

Cilostazol (CLZ) is an FDA approved therapeutic that is indicated for patients with intermittent claudication disease. CLZ is a selective inhibitor for phosphodiesterase 3A (PDE3A); an enzyme that controls oocyte maturation in many mammals including humans. Recently, CLZ has been reported to block pregnancy and oocyte maturation in mice. The objective of the present work was to evaluate the potential non-steroidal contraceptive capacity of CLZ using a more advanced translational model for humans. Three groups of naturally cycling sows were treated orally with 0, 100, or 200mg CLZ, twice a day (bid), for 6days before estrus and continued for three days after estrus. Each sow was mated by one of two proven fertile boars on alternate days during estrus. CLZ dose of 100mg, bid, completely blocked pregnancy in sows when compared to control sows (P<0.01). However, the 200mg dose of CLZ, bid, failed to significantly block pregnancy in pigs. No significant differences were observed in heart rates of treated and control animals. Re-mating of the previously treated sows exhibited normal pregnancies and litter sizes. This study shows that CLZ is capable of producing a reversible non-steroidal contraceptive effect without adverse effects on the heart rate in pigs. The observed contraceptive effect of CLZ was at doses similar to those indicated to humans. This FDA approved agent, for treatment of patients with intermittent claudication, may have an additional therapeutic effect as a non-steroidal contraceptive agent. Cilostazol merits further evaluation in women and might be useful for controlling the population of homeless animals.

Welfare of Pigs Being Transported over Long Distances Using a Pot-Belly Trailer during Winter and Summer.

Simple SummaryThe pot-belly trailer, which can transport large loads in a single journey, is commonly used for swine transportation in Canada. However, it is generally acknowledged that pot-belly trailers and some specific compartments within this vehicle are worse than others in terms of animal losses. The objective of this study was to evaluate the effects of pot-belly design on animal welfare and meat quality in pigs being transported long distance in two different seasons of the year.A total of 2,145 pigs were transported for 8 h in summer (six trips) and winter (five trips) using a pot-belly trailer accommodating pigs in four locations (upper deck or UD, bottom-nose or BN, middle deck or MD and bottom deck or BD). Heart rate of pigs during loading and transportation and lactate and creatine kinase (CK) concentrations in exsanguination blood were measured. Meat quality was evaluated in the Longissimus thoracis (LT), Semimembranosus (SM) and Adductor (AD) muscles. During summer, pigs loaded in the UD and MD had higher (P < 0.05) heart rate at loading compared to those located in the BD and BN. Blood lactate and CK concentrations were higher (P < 0.001) in winter than in summer. Lactate concentration was higher (P = 0.01) in the blood of pigs transported in the BN. Pigs transported in the BN had higher pHu values in the LT, SM and AD muscles (P = 0.02, P < 0.001 and P = 0.002, respectively) and lower (P = 0.002) drip loss values in the SM muscle. This study confirms that some locations within the PB trailer have a negative impact on the welfare of pigs at loading and during transport with more pronounced effects in the winter due to the additive effect of cold stress.

Early detection of cardiovascular autonomic neuropathy in diabetic pigs using blood pressure and heart rate variability

Cardiac autonomic neuropathy is a common complication in insulin dependent diabetes mellitus. Nevertheless, little is known about when this impairment occurs during the time course of the disease. Analysis of blood pressure (BP) and heart rate (HR) variability could be used to detect early signs of autonomic alteration. To test this proposal, twelve sexually mature male Yucatan miniature pigs were equipped with an arterial catheter for telemetric BP analysis, and with a venous access. BP and HR were recorded together with respiratory movements while the animals were resting in a sling. After the first recording session performed when the pigs were 5 months old, streptozotocin (STZ) was used to induce diabetes in seven pigs, while the five others were controls. BP and HR were measured 3 and 6 months after the onset of diabetes and at a similar age in the controls. BP and HR oscillated at the respiratory range (0.19 Hz). Spectral analysis showed this respiratory component was the main determinant of the short-term variability of BP and HR. Atropine increased HR and BP and markedly diminished the respiratory sinus arrhythmia. Propranolol diminished HR and the respiratory peak of HR. A reduced respiratory oscillation of BP paralleled the diminution of the respiratory peak of HR. Baroreceptor-HR reflex was estimated using injections of phenylephrine and nitroprusside, and by cross-spectral analysis between BP and HR. Atropine shifted the curve to higher HR values, while propranolol reduced the level of the upper plateau. Atropine decreased both the coherence and gain of the cross-spectral analysis. STZ injection resulted in a type 1 diabetes. At 3 months, diabetic pigs exhibited low levels of BP and a reduced overall variability of HR and BP. Spectral analysis indicated the respiratory sinus arrhythmia was markedly reduced. In addition, the sensitivity of the baroreceptor-HR reflex was reduced. At a latter stage of diabetes these alterations were marked and the level of the resting HR was increased. These data demonstrate the dual (vagal and sympathetic) control of HR in pigs and the dominant role of respiration in the genesis of HR and BP fluctuations. The spectral and cross-spectral analysis of BP and HR were altered after 3 months of diabetes and could be proposed as early detectors of cardiac autonomic neuropathy.

Influence of vertical vibration on heart rate of pigs.

Pigs with a body weight between 15 and 20 kg were vibrated in the vertical direction for 1 h at 2, 8, and 18 Hz, in combination with root mean square (RMS) acceleration magnitudes of 1 or 3 m/s2. Welfare and stress were quantified by comparing heart rate characteristics during a control period (2200 to 0600) before vibration exposure and during vibration (1000 to 1100). The level of maximum heart rate and number of ventricular ectopic beats during vibration at 2 and 8 Hz in combination with a RMS acceleration of 3 m/s2 indicated a larger fear response than at 1 m/s2. Isocomfort contours based on mean heart rate during vibration showed the greatest specific sensitivity of the pigs to vibration at a frequency of 8 and 18 Hz, especially in combination with a RMS acceleration of 3 m/s2. During transport, RMS acceleration should be less than 3 m/s2 to protect pigs' welfare. Pigs were more sensitive to acceleration than to frequencies within the range of treatments in this investigation. Although the response of the pigs in this experiment fit within the model concept for adult humans and for domestic fowl, changes in heart rate are dependent on body weight.

Effect of Human Contact on Heart Rate of Pigs

AbstractPigs were selected at random from three lines (homozygous halothane positive, homozygous negative, and the heterozygotes). They were housed for four weeks within standardized environmental conditions with six pigs per pen corresponding to each of the three lines with two treatment combinations (6×3×2). Half of the pigs were allocated to routine care without humans entering the pen, while the other ones received an increased human contact treatment; animal-man interaction times were recorded. Before and after the four-week experimental period, pigs were housed individually for one day. A blood sample was taken for beta-endorphin analysis and heart rate was measured. The final heart rate measurements were continued during a transport of two hours. With respect to animal-man interaction times no clear treatment effect was observed. Increased human contact lowered the plasma beta-endorphin content to a greater extent as a function of time, while heart rate also became lower. The latter may result in an improved heart function during handling and transport. Differences with regard to the halothane gene were observed during housing conditions, but not during transport.

Stereotypic behavior and heart rate in pigs

Heart rate responses to feeding of both loose-housed and tethered sows, some of which engaged in persistent behavioral stereotypies, were recorded telemetrically in order to determine if stereotypic behavior occurs in response to, and serves to reduce increased sympathetic nervous activity. Heart rates rose in response to feeding (after which stereotypic behavior is most common) and this was greater for tethered sows. This response was partly blocked by a beta-adrenoreceptor antagonist (carazolol), but not by naloxone, although the latter tended to lead to overall increases in heart rate. Thus long-term tethering of sows leads to greater sympathetic nervous responses to feeding. No consistent relationships were found between heart rate and the performance of stereotypic behavior. In Experiment 1, using sows tethered for 6–8 months, neither basal heart rates nor heart rates following naloxone or carazolol differed between high- and low-stereotyping sows. In Experiment 2, using sows tethered for 1–2 months, high-stereotyping sows had lower basal heart rates than low-stereotyping sows. Marked reductions in heart rate caused by a beta-adrenoreceptor blocker did not lead to any change in stereotypic behavior, and preventing stereotypic behavior led to a reduction not an increase in heart rates. The results suggest that stereotypies are performed in situations where heart rate is high, but they provide no evidence that stereotypies reduce this heart rate.

Magnitude of myocardial potassium changes during acute alterations in pacing frequency in the in situ pig heart.

A transient loss of potassium from cardiac tissue during increments in stimulation frequency has been found in different isolated preparations, but there is no agreement as to the magnitude and time course of this loss. In the present study myocardial potassium balance was determined during changes in heart rate in pigs with an intact circulation. The left azygos vein, which drains into the coronary sinus in this species, was cannulated and a shuntline to the right atrium established. Coronary sinus blood was thus continuously drawn from the shunt by a pump, without admixture of systemic venous blood, and myocardial release and uptake of potassium were determined before, during, and after periods of pacing tachycardia. A transient mean(SEM) loss of potassium (13.0(5.6) mumol X 100 g-1 or about 0.25 mumol per beat change in heart rate) occurred during the first 90 s after increasing heart rate by a mean(SEM) of 53(4) beats X min-1. By discontinuing pacing heart rate returned to control values (mean(SEM) -43(7) beats X min-1), and myocardial potassium uptake ensued (mean(SEM) 9.8(3.3) mumol X 100 g-1 or 0.23 mumol per beat change in heart rate). The peak changes in coronary sinus potassium concentrations occurred 30 s after heart rate). The potassium lost during the periods of pacing tachycardia represented only about 0.2% of total myocardial potassium, equivalent to a reduction in intracellular potassium concentration of 0.3 mmol X litre-1. Since intracellular sodium and calcium concentrations are closely linked to the potassium concentration, the observed changes in potassium concentrations, although small, may be related to the positive inotropic effect of pacing tachycardia (the positive staircase phenomenon).