Biomedical subjects

P C Schön

Publications and source records attributed to P C Schön.

4 recordsLinked to original sources

PubMed2007

Altered vocalization rate during the estrous cycle in dairy cattle.

Correct detection of estrus is a problem in dairy herds. In practice, several procedures exist for detection of estrus besides conventional visual observation by humans. These procedures deliver very different results regarding detection of estrus. It is known that the calls of female mammals can contain information about reproductive status. It is also suspected that the vocalizations of cattle contain information about age, sex, dominance status, and stage in the estrous cycle. In the present study, a methodology for the continuous automatic recording of vocalization of heifers during the periestrous period is presented. It was shown in 10 tethered heifers that the estrous climax results in an increase in vocalization rate. Vocalization rate of heifers increased approximately 84% from d -2 to 0 (related to observed estrus) and approximately 59% from d -1 to d 0. After d 0, vocalization rate decreased about 79%. Increased vocalization was correlated with the visual observation of estrus by humans. We also found 2 different structures in the vocalization of heifers. The harmonic structure showed regular frequency bands, whereas the nonharmonic structure was noisy. The hypothesis that the disharmonic structure increases near the estrous climax was confirmed. Hence, it seems possible to get information about stage of the estrous cycle of dairy cattle by means of monitoring vocalization. The presented method of automatically detecting the rate of cattle vocalization (patent pending) could be used solely or in combination with other automated systems for detecting estrus and could considerably increase current estrus detection rates once its applicability can be demonstrated in nontethered cattle.

Animals↗

PubMed2001

Linear prediction coding analysis and self-organizing feature map as tools to classify stress calls of domestic pigs (Sus scrofa).

It is assumed that calls may give information about the inner (emotional) state of an animal. Hence, in the last years sound analysis has become an increasingly important tool for the interpretation of the behavior, the health condition, and the well-being of animals. A procedure was developed that allows the characterization, classification, and visualization of the cluster structures of stress calls of domestic pigs (Sus scrofa). Based on the acoustic model of the sound production the extraction of features from calls was performed with linear prediction coding (LPC). A vector-based self-organizing neuronal network was trained with the determined LPC coefficients, resulting in a feature map. The cluster structure of the calls was then visualized with a unified matrix and the neurons were labeled for their input origin. The basic applicability of the procedure was tested by using two examples which were of special interest for a possible evaluation of the normal farming practice. The procedure worked well both in discriminating individual piglets by their scream characteristics and in classifying pig stress calls vs other calls and noise occurring under normal farming conditions.

Acoustics↗

PubMed1999

Effects of dominance and familiarity on behaviour and plasma stress hormones in growing pigs during social confrontation.

Behavioural patterns and plasma adrenaline, noradrenaline and cortisol responses were studied in domestic pigs with different dominance status during 10-h social confrontation tests with a familiar and an unfamiliar group. Eight trials were carried out, where in each trial two groups of nine growing pigs (12 weeks old) were randomly formed. The pigs with the highest (HR) and lowest (LR) rank from each group were selected as test animals, provided with surgically implanted catheters and kept in single housing for 2 to 3 weeks. After this period, each test animal was introduced once into the familiar and once into the unfamiliar group for 10 h. Introduction of the test animals into the groups caused frequent agonistic interactions during the first 30 min and significantly more agonistic interactions during the confrontation with the unfamiliar group. The agonistic behaviour was accompanied by a rapid increase of plasma catecholamines and cortisol. HR pigs showed significantly higher plasma catecholamine concentrations and more agonistic interactions during the first 30 min compared with the LR pigs. During confrontation with the unfamiliar group, HR pigs experienced more defeats and showed a higher increase of plasma cortisol levels than during the confrontation with the familiar group. No influences of rank or familiarity were found on the other behavioural patterns examined. The results show that agonistic behaviour and activation of the sympatho-adrenomedullary and the hypothalamic-pituitary-adrenal system in pigs during a social confrontation test are determined by the former dominance rank of the animals and the familiarity of the group.

Animals↗

PubMed1999

Monitoring of piglets' open field activity and choice behaviour during the replay of maternal vocalization: a comparison between Observer and PID technique.

The paper presents a new system for the automatic monitoring of open field activity and choice behaviour of medium-sized animals. Passive infrared motion detectors (PID) were linked on-line via a digital I/O interface to a personal computer provided with self-developed analysis software based on LabVIEW (PID technique). The set up was used for testing 18 one-week-old piglets (Sus scrofa) for their approach to their mother's nursing vocalization replayed through loudspeakers. The results were validated by comparison with a conventional Observer technique, a computer-aided direct observation. In most of the cases, no differences were seen between the Observer and PID technique regarding the percentage of stay in previously defined open field segments, the locomotor open field activity, and the choice behaviour. The results revealed that piglets are clearly attracted by their mother's nursing vocalization. The monitoring system presented in this study is thus suitable for detailed behavioural investigations of individual acoustic recognition. In general, the PID technique is a useful tool for research into the behaviour of individual animals in a restricted open field which does not rely on subjective analysis by a human observer.

Animals↗