815 research outputs found
Individual behavioural characteristics in pigs and their consequences for pig husbandry
No full textIntroductionThe main aspect of this thesis is individual behavioural variation. Behavioural variability among individuals within a population may provide information on strategies or roles in social behaviour, on personality traits and individual recognition. Generally, this behavioural variability becomes overt in stressful situations. Recent data have shown the existence of basically two different coping strategies, active or passive. These different coping styles resemble the two (classical) behavioural stress responses, fight-flight vs. conservation-withdrawal, each with its own characteristic biological pattern. The success of the individual coping response depends on the environmental conditions and, therefore, it is highly surprising that each individual appears to be prediposed to one or the other coping strategy. This suggests a genetic or ontogenetic basis, but recent life experiences will have a significant role also. The idiosyncratic response pattern to a challenge has been shown in many species (humans; monkeys; dogs; tree shrews; etcetera), and hence it may be postulated that this also holds for pigs. If so, these individual behavioural characteristics will have important practical implications in understanding the social relations among group-housed pigs in intensive farm conditions. A stable social structure in the group, and thus a proper group composition, may be a function of the individual behavioural characteristics of each group member. However, until now little research has been conducted to reveal possible patterns underlying a proper group composition in pigs, and subsequently how such mechanisms could be applied in intensive pig husbandry. The present study aims at these aspects.Social statusIn chapter 1, the individual variation in disease susceptibility and immune reactivity of pigs is described in relation to their individual social status in a stable social group. This social status was determined by the outcome of social ranking fights and food competition tests. There was a substantial agreement between the social status determined by these ranking fights and food competition tests. Since these tests were made at quite different ages (respectively; during the suckling period, and on day 50, on day 65, and on day 100), this indicates a relatively stable social structure in the group. At an age of approximately ten weeks, all pigs were challenged intranasally with an Aujeszky virus. Mortality and morbidity were highest among subordinate pigs compared to subdominant and dominant ones. A specific lymphocyte stimulation test, using purified Apjeszky virus as an antigenic stimulus, showed that the cell-mediated immunity (CMI) against the Aujeszky virus was higher for the dominant pigs than for the subdominant and subordinate ones.These findings showed that there were large individual differences in immune reactivity and disease susceptibility in pigs partly related to their individual social status in the group. However, social behaviour of an animal that lives in a social organization is also determined by its individual way of handling stressful situations i.e., its coping strategy. Therefore, the individual coping response may well be another basis for different internal biological programs, which may eventually lead to individual differences in disease susceptibility. In chapter 2 the hypothesis was tested whether consistent individual behavioural characteristics in pigs exist.Individual behavioural characteristicsDuring the suckling period, piglets were classified as aggressive or as non-aggressive individuals in two successive social confrontation (SC) tests by two observers. Substantial agreement in this classification existed between observers and between both SC tests. Moreover, the aggressive behavioural elements observed after mixing at 10 and again at 15 weeks of age were mainly shown by pigs that were classified as the aggressive ones in the two social confrontation tests shortly after birth; this indicates that the behavioural response pattern of the individuals remained consistent over a long period of time. In a non-social backtest piglets were restrained in a supine position for sixty seconds, and classified as resistant (R;>two escape attempts), intermediate Q; = two escape attempts), or as non-resistant (NR; < two escape attempts). Based upon the outcome of five successive backtests piglets were eventually classified as R (n=95), as NR (n=77), or as Doubtful (n=46). Results showed that two backtests performed on piglets at an early age may suffice for practical use. A striking finding was the good association that existed between the outcome of the backtests and of the SC test. The individuals that resisted in the backtests were the aggressive ones in a social situation, while the non-resistant individuals were the non-aggressive ones. This association and the strong consistency over time strongly suggests an individual behavioural strategy to cope with conflict situations. The idiosyncratic characteristics indicate a bimodal distribution in coping behaviour in pigs; they are active (aggressive and resistant; A/R) or passive (non-aggressive and non-resistant; NA/NR) pigs.Individual physiological characteristicsThe way these individual behavioural strategies in pigs relate to different behavioural, physiological, and endocrine responses under stress conditions is illustrated in chapter 3. For this, 32 A/R and 32 NA/NR pigs were selected and individually tested in an open field (OF) test at three and eight weeks of age. While A/R pigs more than NA/NR ones tried to escape the OF, the A/R pigs vocalized less during the OF procedure than the NA/NR ones did. Furthermore, the A/R ones explored a novel object inside the OF rapidly and superficially, whereas the NA/NR ones did so gradually but more intensively. The cortisol response to the OF (t=0/t=90) differed between the A/R and the NA/NR pigs. The cortisol response to a farmacological dosis ACTH 1-39 (2.5 IU/kg live weight/pig) at three and eight weeks of age showed no significant differences between both types of pigs. Nonetheless, the basal cortisol levels were consistently higher for NA/NR pigs than for A/R ones, and this was eventually accompanied by adrenal hypertrophy in the former. The mean heart rate (HR) in beats/min (bpm) was higher of the A/R pigs compared to the NA/NR ones in two backtests. Moreover, in reaction to the novel object (a falling bucket) in the (second) OF HR of the A/R pigs substantially increased (23.9 bpm = 15.5%), while HR of the NA/NR pigs only slightly increased (4.5 bpm = 2.9%). Surprisingly, one-third of the NA/NR individuals even showed a HR decrease (bradycardia) in response to the falling bucket. This implies that the active pigs (A/R) reacted predominantly with a sympathetic response, and the passive pigs (NA/NR) with a parasympathetic one; these findings strongly parallel data found in other animals and humans. The sympathetic response of the active pigs resulted in heart deviations. Thus, active and passive pigs displayed consistent individual differences in behavioural, physiological, and endocrine responses to stress situations leading to different stress pathologies.Individual immunological characteristicsChapter 4 reports about individual differences in cell-mediated and humoral immunity as related to different coping styles in pigs. The immune reactivity of 32 A/R and 32 NA/NR pigs was tested in relation to stress using several cell-mediated (CMI) and humoral immunological tests. Results indicated that the active pigs had a higher in vivo and in vitro CMI to non-specific and specific antigens than the passive pigs. Furthermore, in reaction to stressors applied in the present study (i.e., weaning, new environment, transportation, mixing) active pigs had a reduced but temporary CMI response in the first phase of stress, while passive pigs showed a more chronic impairment. In contrast, the passive pigs displayed higher levels of specific antibodies than the active ones. This suggests a converse relationship in the individual pig between CMI and humoral immunity, in that active pigs had a high CMI but a low humoral immunity, whereas passive pigs had a low CMI but a high humoral immunity. This converse relationship may be associated with different levels of glucocorticoids as described in chapter 3. In conclusion, active and passive pigs clearly differed in their immune reactivity to stressful situations.Practical implicationsHow far group composition based on the individual coping characteristics may influence the growing up of fattening pigs was tested at a commercial closed farm (cf. chapter 5). During the suckling period, piglets of this farm were individually tested in two successive backtests, and classified as R, NR, or as D. At nine weeks of age, the pigs were grouped into six pens with only R pigs (R pens), six pens with only NR pigs (NR pens), and six pens with both R and NR ones (R/NR pens). The average daily weight gain (ADWG; grams/day) was highest of the pigs in the R/NR pens compared to the pigs in the R pens and in the NR pens. Moreover, the coefficient of variation of A~ was lower among R/NR pens than among R pens or NR pens. The carcass weight and meat% was somewhat higher and carcass classification was better of the pigs in the R/NR pens than the pigs in the R pens and in the NR pens. Additionally, pigs in the R/NR pens had less pleurisy than the pigs in the other pens, whereas the number of pigs with stomach wall damage was highest for pigs in the NR pens. Groups consisting of both active (R pigs) and passive (NR pigs) individuals seem to better fit each other than groups with only active or with only passive ones and, thus it is worthwhile to compose groups of pigs based on their individual behavioural characteristics. In practice, good management implies besides perfect climatic and feeding conditions also attention for and understanding of the social environment of the farm animals.General DiscussionIn the general discussion three major topics are discussed: 1) do the behavioural differences in pigs represent idiosyncratic response patterns; 2) do the individual behavioural characteristics in pigs relate to different autonomic nervous and immune reactivity under stress conditions and 3) the relevance of applying behavioural studies in pigs in practice. Especially the intriguing finding that under stressful conditions active and passive pigs need each other to develop a stable social organization needs further research
Individual behavioural characteristics in pigs and their consequences for pig husbandry
No full textIntroductionThe main aspect of this thesis is individual behavioural variation. Behavioural variability among individuals within a population may provide information on strategies or roles in social behaviour, on personality traits and individual recognition. Generally, this behavioural variability becomes overt in stressful situations. Recent data have shown the existence of basically two different coping strategies, active or passive. These different coping styles resemble the two (classical) behavioural stress responses, fight-flight vs. conservation-withdrawal, each with its own characteristic biological pattern. The success of the individual coping response depends on the environmental conditions and, therefore, it is highly surprising that each individual appears to be prediposed to one or the other coping strategy. This suggests a genetic or ontogenetic basis, but recent life experiences will have a significant role also. The idiosyncratic response pattern to a challenge has been shown in many species (humans; monkeys; dogs; tree shrews; etcetera), and hence it may be postulated that this also holds for pigs. If so, these individual behavioural characteristics will have important practical implications in understanding the social relations among group-housed pigs in intensive farm conditions. A stable social structure in the group, and thus a proper group composition, may be a function of the individual behavioural characteristics of each group member. However, until now little research has been conducted to reveal possible patterns underlying a proper group composition in pigs, and subsequently how such mechanisms could be applied in intensive pig husbandry. The present study aims at these aspects.Social statusIn chapter 1, the individual variation in disease susceptibility and immune reactivity of pigs is described in relation to their individual social status in a stable social group. This social status was determined by the outcome of social ranking fights and food competition tests. There was a substantial agreement between the social status determined by these ranking fights and food competition tests. Since these tests were made at quite different ages (respectively; during the suckling period, and on day 50, on day 65, and on day 100), this indicates a relatively stable social structure in the group. At an age of approximately ten weeks, all pigs were challenged intranasally with an Aujeszky virus. Mortality and morbidity were highest among subordinate pigs compared to subdominant and dominant ones. A specific lymphocyte stimulation test, using purified Apjeszky virus as an antigenic stimulus, showed that the cell-mediated immunity (CMI) against the Aujeszky virus was higher for the dominant pigs than for the subdominant and subordinate ones.These findings showed that there were large individual differences in immune reactivity and disease susceptibility in pigs partly related to their individual social status in the group. However, social behaviour of an animal that lives in a social organization is also determined by its individual way of handling stressful situations i.e., its coping strategy. Therefore, the individual coping response may well be another basis for different internal biological programs, which may eventually lead to individual differences in disease susceptibility. In chapter 2 the hypothesis was tested whether consistent individual behavioural characteristics in pigs exist.Individual behavioural characteristicsDuring the suckling period, piglets were classified as aggressive or as non-aggressive individuals in two successive social confrontation (SC) tests by two observers. Substantial agreement in this classification existed between observers and between both SC tests. Moreover, the aggressive behavioural elements observed after mixing at 10 and again at 15 weeks of age were mainly shown by pigs that were classified as the aggressive ones in the two social confrontation tests shortly after birth; this indicates that the behavioural response pattern of the individuals remained consistent over a long period of time. In a non-social backtest piglets were restrained in a supine position for sixty seconds, and classified as resistant (R;>two escape attempts), intermediate Q; = two escape attempts), or as non-resistant (NR; < two escape attempts). Based upon the outcome of five successive backtests piglets were eventually classified as R (n=95), as NR (n=77), or as Doubtful (n=46). Results showed that two backtests performed on piglets at an early age may suffice for practical use. A striking finding was the good association that existed between the outcome of the backtests and of the SC test. The individuals that resisted in the backtests were the aggressive ones in a social situation, while the non-resistant individuals were the non-aggressive ones. This association and the strong consistency over time strongly suggests an individual behavioural strategy to cope with conflict situations. The idiosyncratic characteristics indicate a bimodal distribution in coping behaviour in pigs; they are active (aggressive and resistant; A/R) or passive (non-aggressive and non-resistant; NA/NR) pigs.Individual physiological characteristicsThe way these individual behavioural strategies in pigs relate to different behavioural, physiological, and endocrine responses under stress conditions is illustrated in chapter 3. For this, 32 A/R and 32 NA/NR pigs were selected and individually tested in an open field (OF) test at three and eight weeks of age. While A/R pigs more than NA/NR ones tried to escape the OF, the A/R pigs vocalized less during the OF procedure than the NA/NR ones did. Furthermore, the A/R ones explored a novel object inside the OF rapidly and superficially, whereas the NA/NR ones did so gradually but more intensively. The cortisol response to the OF (t=0/t=90) differed between the A/R and the NA/NR pigs. The cortisol response to a farmacological dosis ACTH 1-39 (2.5 IU/kg live weight/pig) at three and eight weeks of age showed no significant differences between both types of pigs. Nonetheless, the basal cortisol levels were consistently higher for NA/NR pigs than for A/R ones, and this was eventually accompanied by adrenal hypertrophy in the former. The mean heart rate (HR) in beats/min (bpm) was higher of the A/R pigs compared to the NA/NR ones in two backtests. Moreover, in reaction to the novel object (a falling bucket) in the (second) OF HR of the A/R pigs substantially increased (23.9 bpm = 15.5%), while HR of the NA/NR pigs only slightly increased (4.5 bpm = 2.9%). Surprisingly, one-third of the NA/NR individuals even showed a HR decrease (bradycardia) in response to the falling bucket. This implies that the active pigs (A/R) reacted predominantly with a sympathetic response, and the passive pigs (NA/NR) with a parasympathetic one; these findings strongly parallel data found in other animals and humans. The sympathetic response of the active pigs resulted in heart deviations. Thus, active and passive pigs displayed consistent individual differences in behavioural, physiological, and endocrine responses to stress situations leading to different stress pathologies.Individual immunological characteristicsChapter 4 reports about individual differences in cell-mediated and humoral immunity as related to different coping styles in pigs. The immune reactivity of 32 A/R and 32 NA/NR pigs was tested in relation to stress using several cell-mediated (CMI) and humoral immunological tests. Results indicated that the active pigs had a higher in vivo and in vitro CMI to non-specific and specific antigens than the passive pigs. Furthermore, in reaction to stressors applied in the present study (i.e., weaning, new environment, transportation, mixing) active pigs had a reduced but temporary CMI response in the first phase of stress, while passive pigs showed a more chronic impairment. In contrast, the passive pigs displayed higher levels of specific antibodies than the active ones. This suggests a converse relationship in the individual pig between CMI and humoral immunity, in that active pigs had a high CMI but a low humoral immunity, whereas passive pigs had a low CMI but a high humoral immunity. This converse relationship may be associated with different levels of glucocorticoids as described in chapter 3. In conclusion, active and passive pigs clearly differed in their immune reactivity to stressful situations.Practical implicationsHow far group composition based on the individual coping characteristics may influence the growing up of fattening pigs was tested at a commercial closed farm (cf. chapter 5). During the suckling period, piglets of this farm were individually tested in two successive backtests, and classified as R, NR, or as D. At nine weeks of age, the pigs were grouped into six pens with only R pigs (R pens), six pens with only NR pigs (NR pens), and six pens with both R and NR ones (R/NR pens). The average daily weight gain (ADWG; grams/day) was highest of the pigs in the R/NR pens compared to the pigs in the R pens and in the NR pens. Moreover, the coefficient of variation of A~ was lower among R/NR pens than among R pens or NR pens. The carcass weight and meat% was somewhat higher and carcass classification was better of the pigs in the R/NR pens than the pigs in the R pens and in the NR pens. Additionally, pigs in the R/NR pens had less pleurisy than the pigs in the other pens, whereas the number of pigs with stomach wall damage was highest for pigs in the NR pens. Groups consisting of both active (R pigs) and passive (NR pigs) individuals seem to better fit each other than groups with only active or with only passive ones and, thus it is worthwhile to compose groups of pigs based on their individual behavioural characteristics. In practice, good management implies besides perfect climatic and feeding conditions also attention for and understanding of the social environment of the farm animals.General DiscussionIn the general discussion three major topics are discussed: 1) do the behavioural differences in pigs represent idiosyncratic response patterns; 2) do the individual behavioural characteristics in pigs relate to different autonomic nervous and immune reactivity under stress conditions and 3) the relevance of applying behavioural studies in pigs in practice. Especially the intriguing finding that under stressful conditions active and passive pigs need each other to develop a stable social organization needs further research
Heroïneverstrekking en de consequenties voor verwervingscriminaliteit en overlast; een terreinverkenning
No full textHeroïneverstrekking en de consequenties voor verwervingscriminaliteit en overlast; een terreinverkenning
No full text’t Klooster, Hengelo (gemeente Bronckhorst)
No full textADC ArcheoProjecten heeft in september 2022 een inventariserend veldonderzoek in de vorm van een karterend booronderzoek uitgevoerd op de locatie ’t Klooster in Hengelo, gemeente Bronckhorst. Dit onderzoek volgt op het in januari tot en met maart 2022 uitgevoerde bureau- en inventariserend veldonderzoek (verkennend booronderzoek). De aanleiding voor deze onderzoeken is de voorgenomen aanleg van ondergrondse putten voor drinkwaterwinning en bijbehorend leidingwerk. Hiervoor is een omgevingsvergunning noodzakelijk.
Bij het verkennend booronderzoek werd vastgesteld dat de bodemopbouw uit dekzand (Laagpakket van Wierden van de Formatie van Boxtel) met plaatselijk daarop een laag of pakket stuifzand (Laagpakket van Kootwijk van de Formatie van Boxtel) bestaat. In het merendeel van de boringen werd in de top van het dekzand een (overstoven) podzolbodem aangetroffen. Op grond hiervan werd de middelhoge verwachting voor archeologische resten vanaf het Laat-Paleolithicum gehandhaafd. In enkele delen van het plangebied was als gevolg van verstoringen geen podzolbodem meer aanwezig. Voor deze delen werd de middelhoge verwachting bijgesteld naar een lage verwachting.
De delen met een intacte podzolbodem zijn nader onderzocht middels een karterend booronderzoek. Dit onderzoek had als doel het opsporen van archeologische vindplaatsen met een strooiing van overwegend vuursteen. Hiertoe zijn 55 boringen gezet met een Edelman met een diameter van 15 cm. De opgeboorde grond is gezeefd over een zeef met een maaswijdte van 4 mm.
Bij het karterend booronderzoek zijn in twee boringen (nummers 17 en 48) indicatoren aangetroffen bestaande uit fragmenten houtskool. Houtskool betreft een zogenaamde secundaire archeologische indicator, omdat het ook op natuurlijke wijze kan ontstaan, bijvoorbeeld bij een bosbrand. Vanwege het ontbreken van primaire indicatoren is een relatie met een archeologische vindplaats niet zeker. Om de relatie met een archeologische vindplaats aan te tonen is besloten ter plaatse van de boringen met indicatoren een profielkuil aan te leggen. Daarbij is vastgesteld dat de aangetroffen houtskoolfragmenten geen archeologische context hebben. Gedurende de aanleg van profielkuil 1, zijn de A- en B-horizonten bemonsterd en gezeefd. Dit heeft geen nieuwe houtskoolfragmenten opgeleverd. In vergelijking met de overige resultaten van het plangebied kan worden geconcludeerd dat het houtskool fragment dat is aangetroffen in boring 17 hoogstwaarschijnlijk een natuurlijke oorsprong heeft
Decentralised Clinical Guidelines Modelling with Lightweight Coordination Calculus
No full textBackground:Clinical protocols and guidelines have been considered as a major means to ensure that cost-effective services are provided at the point of care. Recently, the computerisation of clinical guidelines has attracted extensive research interest. Many languages and frameworks have been developed. Thus far, however, an enactment mechanism to facilitate decentralised guideline execution has been a largely neglected line of research. It is our contention that decentralisation is essential to maintain a high-performance system in pervasive health care scenarios. In this paper, we propose the use of Lightweight Coordination Calculus (LCC) as a feasible solution. LCC is a light-weight and executable process calculus that has been used successfully in multi-agent systems, peer-to-peer (p2p) computer networks, etc. In light of an envisaged pervasive health care scenario, LCC, which represents clinical protocols and guidelines as message-based interaction models, allows information exchange among software agents distributed across different departments and/or hospitals. Results: We outlined the syntax and semantics of LCC; proposed a list of refined criteria against which the appropriateness of candidate clinical guideline modelling languages are evaluated; and presented two LCC interaction models of real life clinical guidelines. Conclusions: We demonstrated that LCC is particularly useful in modelling clinical guidelines. It specifies the exact partition of a workflow of events or tasks that should be observed by multiple "players" as well as the interactions among these "players". LCC presents the strength of both process calculi and Horn clauses pair of which can provide a close resemblance of logic programming and the flexibility of practical implementation
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