Toxoplasma gondii infection in pork produced in France.

The aim of this study was to assess the seroprevalence of the Toxoplasma gondii parasite in pork produced in France, and to determine infection risk factors. An innovative survey was designed based on annual numbers of slaughtered pigs from intensive and outdoor farms in France. A total of 1549 samples of cardiac fluids were collected from pig hearts to determine seroprevalence using a Modified Agglutination Test. Of those, 160 hearts were bio-assayed in mice to isolate live parasites. The overall seroprevalence among fattening pigs was 2·9%. The adjusted seroprevalence in pigs from intensive farms was 3·0%; the highest in sows (13·4%); 2·9% in fattening pigs and 2·6% in piglets. Adjusted seroprevalence in fattening animals from outdoor farms was 6·3%. Strains were isolated from 41 animals and all were genotyped by Restriction Fragment Length Polymorphism as type II. Risk-factor analysis showed that the risk of infection was more than three times higher for outdoor pigs, and that sows' risk was almost five times higher than that of fattening animals. This study provides further evidence of extensive pork infection with T. gondii regardless of breeding systems, indicating that farm conditions are still insufficient to guarantee 'Toxoplasma-free pork'.

Induction of sulfadiazine resistance in vitro in Toxoplasma gondii.

We induced sulfadiazine resistance in two sulfadiazine sensitive strains of Toxoplasma gondii, RH (Type I) and ME-49 (Type II) in vitro by using drug pressure. At first, sulfadiazine susceptibility of the two sensitive strains and two naturally resistant strains of T. gondii was evaluated on Vero cells using an enzyme-linked immunosorbent assay (ELISA). The IC(50) values of sulfadiazine were 77 µg/mL for RH, 51 µg/mL for ME-49 and higher than 1000 µg/mL for the two natural resistant strains. Secondly, induced resistance of the strains by gradually increase sulfadiazine concentration was verified by this test, which resulted IC(50) values at higher than 1000 µg/mL. In conclusion we developed in vitro two sulfadiazine resistant strains called RH-R(SDZ) and ME-49-R(SDZ). These strains resistant to sulfadiazine would be useful to characterize resistance mechanisms to sulfadiazine.

Animal welfare in different human cultures, traditions and religious faiths.

Animal welfare has become a growing concern affecting acceptability of agricultural systems in many countries around the world. An earlier Judeo-Christian interpretation of the Bible (1982) that dominion over animals meant that any degree of exploitation was acceptable has changed for most people to mean that each person has responsibility for animal welfare. This view was evident in some ancient Greek writings and has parallels in Islamic teaching. A minority view of Christians, which is a widespread view of Jains, Buddhists and many Hindus, is that animals should not be used by humans as food or for other purposes. The commonest philosophical positions now, concerning how animals should be treated, are a blend of deontological and utilitarian approaches. Most people think that extremes of poor welfare in animals are unacceptable and that those who keep animals should strive for good welfare. Hence animal welfare science, which allows the evaluation of welfare, has developed rapidly.

Validity of the test-table-test for Nordic skiing for classification of paralympic sit-ski sports participants.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To assess the interrater reliability and validity of the test-table-test (TTT) with which paralympic sports participants involved in Nordic sit-ski sports may be classified. SETTING: Movement laboratory in a rehabilitation centre, The Netherlands. METHODS: Thirty-three persons with a spinal cord injury caudally to Th2, a leg amputation, poliomyelitis affecting the trunk and/or lower extremities, or cerebral palsy participated. Subjects were classified according to a classification system for Nordic skiing (that is, five subclasses between LW10 and LW12) by two raters, involving, among others, a combination of four balance tests called TTT. The validity of the TTT was investigated using a gold standard, involving balance perturbation tests on a force plate and centre of pressure (CoP) displacement measurements. RESULTS: As for the interrater reliability, Spearman's rank-correlation coefficient was 0.95 (P<0.001). As regards the validity of the TTT, correlation coefficients ranging from 0.61 to 0.74 (P<0.001) were found when comparing the data with the gold standard. CONCLUSION: Interrater reliability was high in both scoring and classification. With regard to TTT validity, strong positive correlations between CoP displacement and TTT classification were found. Overall, the results of this study show that the TTT is a reliable and valid test. However, the relations between TTT and CoP displacement in the LW10 and LW10.5 subclasses found in this study are somewhat vague, which could be due to the small number of participants in these subclasses. For the LW10 and LW10.5 subclasses further refinement of the four tests within the TTT is warranted.

Landscape, herd management and within-herd seroprevalence of Toxoplasma gondii in beef cattle herds from Champagne-Ardenne, France.

Toxoplasmosis is the most common parasitic zoonosis worldwide. Its prevalence and impact on human health are highly variable geographically. Humans may be infected by ingesting oocysts from the environment, or bradyzoits contained in meat products from various domestic species, thus data on the dynamics of toxoplasmosis in domestic herds is needed. However, few information is available on the factors that determine the level of infection of cattle herds. In this study, we aimed to estimate within-herd seroprevalence of toxoplasmosis in bovine herds and analyze its variability in relation with environmental characteristics and herd management. We tested the presence of anti Toxoplasma gondii antibodies in 1329 cattle from 24 beef herds in the Champagne-Ardenne region, using the Modified Agglutination Test. Information on herds was collected using a questionnaire. After describing the relationships between explanatory variables, we built a multivariate model using logistic Generalized Linear Models (GLMs) and estimated parameters with a Generalized Estimating Equations (GEE) procedure. The crude seroprevalence at threshold 1:24 equalled 7.8%, which is low, however positive individuals were found in 21 out of 24 herds. The final multivariate model showed that within-herd seroprevalence was highest in herds that were both small and isolated. The presence of cats modified the age-prevalence relationship: maximal seroprevalence was observed in oldest cows in farms without cats, and in youngest individuals in farms with cats. Finally, using a natural water point on pastures was associated to a high within-herd seroprevalence (Odds-Ratio: 1.93). Cows are often exposed to toxoplasmosis, however landscape characteristics (water point, isolation) and herd management (herd size, cats) may affect seroprevalence. Our results may help to find ways of reducing T. gondii prevalence in cattle.

A survey of pork quality in relation to pre-slaughter conditions, slaughterhouse facilities, and quality assurance.

A survey at five pigs' slaughterhouses was performed to investigate the effect of a quality assurance system, pre-slaughter conditions and slaughterhouse facilities on pork quality. Totally, 2246 pigs were included over four transports per slaughterhouse, i.e. two transports were produced according to a quality assurance system and the other two were conventional pigs. Meat quality was measured on 446 pigs. The pH in the longissimus dorsi muscle and the electrical conductivity in the semimembranosus muscle were measured 30min post-mortem. Twenty-four hours later pH and electrical conductivity in both the longissimus dorsi and the semimembranosus muscle were measured. Pigs managed according to a chain quality protocol showed an overall higher potential for improved meat quality. Differences in meat quality between the different slaughterhouses were also found, however they were dependent on muscle type and time of measuring. Influencing factors on pork quality seemed to be stocking density during transport, the handling during offloading the pigs from the truck, stocking density, and air temperature during lairage.

Fear of pain changes movement: Motor behaviour following the acquisition of pain-related fear.

BACKGROUND: According to current fear-avoidance models, changes in motor behaviour (e.g. avoidance) are a key component in the development and maintenance of chronic pain complaints. Yet, experimental research assessing actual behavioural changes following painful events is relatively sparse. This study investigated the effects of pain anticipation on changes in motor behaviour using a fear conditioning paradigm and robot-generated standardized movement trajectories of the upper extremities. METHODS: Pain-free participants (N = 20) performed clockwise and counterclockwise fixed, circular movements with a robotic arm without receiving visual feedback. During fear acquisition, moving in one direction (CS+) was paired with a painful stimulus (pain-US) whereas moving in the other direction (CS-) was not. During the subsequent extinction phase, the pain-US was omitted. We assessed self-reported pain-related fear and urge to avoid the movement, as well as several behavioural measures: Velocity, acceleration, exerted force and force direction. RESULTS: Movements that were paired with pain were associated with increased self-reported pain-related fear and urge to avoid. Moreover, movements that were associated with pain were performed faster, more forcefully and more accurately than movements that were not associated with pain. All these differences diminished during the extinction phase. CONCLUSIONS: The present study demonstrates the utility of robot-generated force feedback in the study of pain-related fear and associated changes in motor behaviour. SIGNIFICANCE: Fear of pain changes movement: Movements associated with pain are performed faster, with more force and higher accuracy than movements that are not associated with pain. These changes can inform us how fear of pain translates into avoidance and escape behaviour, two important constructs in the maintenance of chronic pain.

Effects of environmental enrichment and regrouping on natural autoantibodies-binding danger and neural antigens in healthy pigs with different individual characteristics.

Pigs living in commercial husbandry systems may experience both acute stress due to standard management procedures and chronic stress through limitations in their barren housing environment. This might influence their immune status, including antibody responses to neural and danger autoantigens. Levels of natural autoantibody (NAAb)-binding phosphorylcholine-conjugated bovine serum albumin (PC-BSA) and myelin basic protein (MBP) were measured over time in pigs that were kept in environmental enriched v. barren housing, and that underwent a regrouping test. In total, 480 pigs were housed in 80 pens in either barren or straw-enriched pens from 4 through 23 weeks of age. Blood samples were taken from pigs before (week 8), and 3 days after a 24 h regrouping test (week 9), and at 22 weeks of age. Phosphorylcholine-conjugated bovine serum albumin (PC-BSA) and MBP antibody titres in serum were measured using ELISA. Enriched-housed pigs had higher levels of IgM-binding MBP, and tended to have higher levels of IgG-binding MBP and IgA-binding PC-BSA than barren-housed pigs. Each NAAb measured in this study was affected by gender and litter. These results suggest that enriched housing conditions, as well as acute regrouping stress, have an influence on levels of serum NAAb-binding danger and neural antigens in pigs.

Validation of a behavioral observation tool to assess pig welfare.

Accurately measuring and monitoring of animal behavior is an important factor when assessing on-farm animal welfare. First we developed a feasible and simple method aiming at consistently on-farm measuring of pig's behavior. This test should cover a broad range of welfare-related pig behavior. The reaction towards a novel object, startling, tail and ear biting, play and aggressive behavior, stereotypies, coughing, sneezing, skin lesions, defecation, urination and cleanliness of body and pen are included. The development of accurate measures of on-farm behavior first requires the reliability assessment of the procedure. Therefore, the methodology was tested in a first part by three observers scoring simultaneously and independently pre-defined behavioral characteristics of 108 group-housed fattening pigs. The inter-observer repeatability of the measures was calculated using intraclass correlation coefficients, which ranged from 0.7 to 1. In a second part, the objective was to validate the behavioral characteristics against salivary cortisol, urinary epinephrine and norepinephrine and production traits. Salivary cortisol concentrations significantly increased in ear-bitten pigs and in pigs with tail lesions. Growth rate significantly dropped when cortisol levels rose. An age effect was also found. The percentage of animals approaching the novel object is positively correlated with the urinary epinephrine concentration. Pigs defecating during the test showed significantly higher epinephrine levels. Urinary norepinephrine concentration decreased significantly with age. Faster growing animals and animals with tail lesions showed significantly higher levels of norepinephrine. Pen dirtiness and number of animals per pen were associated with higher norepinephrine concentrations. Finally, barrows had higher norepinephrine concentrations than sows.

Head current during and blood splashes after electrical stunning in relation to characteristics of the pig's body.

In order to evaluate electrical stunning in relation to the incidence of blood splashes, meat quality and carcass quality parameters, 2035 pigs, heterozygous for the halothane gene, were observed during slaughter at a commercial slaughterhouse. The head current during electrical stunning is significantly higher (P<0.01) in gilts with a lower live weight (P<0.0001) or cold carcass weight (P<0.0001) and a higher lean meat percentage (P<0.0001). Also the incidence of blood splashes in the ham is significantly higher in gilts (P<0.0001) with a higher lean meat percentage (P=0.0028; odds ratio=1.11), a lower live weight (P=0.003; odds ratio=0.98) and a lower type number (P=0.0074; odds ratio=0.64). For barrows, no significant parameters were revealed. These results suggest that the variability in incidence of blood splashes can be explained by the variability of current density depending both on sex and body characteristics. Thus, electrical stunning can be improved by providing an energy level, based on the body characteristics of the pig.

Pre-slaughter sound levels and pre-slaughter handling from loading at the farm till slaughter influence pork quality.

This study investigates the relationship between sound levels, pre-slaughter handling during loading and pork quality. Pre-slaughter variables were investigated from loading till slaughter. A total of 3213 pigs were measured 30 min post-mortem for pH(30LT) (M. Longissimus thoracis). First, a sound level model for the risk to develop PSE meat was established. The difference in maximum and mean sound level during loading, mean sound level during lairage and mean sound level prior to stunning remained significant within the model. This indicated that sound levels during loading had a significant added value to former sound models. Moreover, this study completed the global classification checklist (Vermeulen et al., 2015a) by developing a linear mixed model for pH(30LT) and PSE prevalence, with the difference in maximum and mean sound level measured during loading, the feed withdrawal period and the difference in temperature during loading and lairage. Hence, this study provided new insights over previous research where loading procedures were not included.

Pre-slaughter handling and pork quality.

Environmental variables, as sound levels, were collected during the pre-slaughter process in 18 different Belgian commercial slaughterhouses. Four pre-slaughter phases were determined: firstly after arrival of the truck at the slaughterhouse and just before unloading, secondly during unloading, thirdly at lairage and finally while moving to the stunner. A total of 8508 pigs was examined during the pre-slaughter process, of which the pH(LT) (M. longissimus thoracis), at 30 min post-mortem was measured. For each pre-slaughter phase, variables which might influence pork quality were determined. Moreover, this study made it possible to infer a checklist to represent and predict PSE traits of pork for all kind of pre-slaughter situations. The checklist shows also that the impact on pork quality is more decisive for the variables measured close to the stunning phase. Hence, this information is useful for the industry to optimize handling of pigs, reducing the risk for PSE traits.

Sound levels above 85 dB pre-slaughter influence pork quality.

This study investigates whether sound levels above 85 dB(A), determined in literature as a critical sound level to induce stress in pigs, has also an effect on the pH of pork. Sound levels were recorded during pre-slaughter phases. A measure was taken after the arrival of the truck at the slaughterhouse, during unloading, lairage and just before stunning. The pH of the Longissimus thoracis or lumborum, 30 min after sticking (pH(30LT)) was measured. 8508 pigs were examined and the pH was measured on the carcasses. The results show that the cut-off value of 85 dB(A) during the pre-slaughtering phase is not only a threshold to evaluate animal welfare but can also be associated with a slower drop of pH if sound levels are b85 dB(A). Finally a linear mixed model for pH(30LT) was built with the sound level during lairage and the sound level prior to stunning as independent variables, having statistically the highest impact on pH(30LT) of pork.

Pre-slaughter rectal temperature as an indicator of pork meat quality.

This study investigates whether rectal temperature of pigs, prior to slaughter, can give an indication of the risk of developing pork with PSE characteristics. A total of 1203 pigs were examined, measuring the rectal temperature just before stunning, of which 794 rectal temperatures were measured immediately after stunning. pH30LT (M. Longissimus thoracis) and temperature of the ham (Temp30Ham) were collected from about 530 carcasses, 30 min after sticking. The results present a significant positive linear correlation between rectal temperature just before and after slaughter, and Temp30Ham. Moreover, pH30LT is negatively correlated with rectal temperature and Temp30Ham. Finally, a linear mixed model for pH30LT was established with the rectal temperature of the pigs just before stunning and the lairage time. This model defines that measuring rectal temperature of pigs just before slaughter allows discovery of pork with PSE traits, taking into account pre-slaughter conditions.

Lung lesions increase the risk of reduced meat quality of slaughter pigs.

Lung lesions of about 1000 pigs (nN) were scored in the slaughter line. Carcass weight, back fat thickness, loin muscle depth, pHi and PQMi were measured on 460 pigs. Twenty-four hours after slaughter pHu, PQMu, brightness, redness, yellowness and drip loss were measured on 59 carcasses. A score for lung lesions was assessed at batch level, based on observations of all pigs in that batch, i.e. about 130. Pigs systematically selected from batches scoring more than 25% lung lesions had a lower pH of LD muscle (P≤0.0003) and a six fold higher risk for P(ale)S(oft)E(xudative) traits (P≤0.050) compared to batches scoring less than 5%.

Automated reading and processing of quantitative IgG, IgM, IgA, and IgE isotypic agglutination results in microplates. Development and application in parasitology-mycology.

Microplate agglutination techniques represent a simple and commonly used approach for the quantitative or qualitative isotypic analysis of specific antibodies. However, they require optical reading by the investigator and are thus prone to an important degree of variability. In order to solve some of the problems associated with the variability of optical readings, we have used an automatic reader scanning each of the 96 wells of a standard microplate in 32 different locations. The inherent advantages of the automatic reader were further maximized by coupling it to a dedicated computer running customized software designed to process data coming on-line from the spectrophotometer. This approach has been applied to the diagnosis of human toxoplasmosis and candidosis. Suspensions of Toxoplasma gondii tachyzoites or of sensitised erythrocytes were used for the determination of IgG antibodies or the quantification of IgM, IgA, or IgE specific isotypes. This procedure allows the simple and reproducible collection of objective results. Moreover, it permits a reduction in cut-off values and direct interpretation of results with automatic conversion of scores into titer, units, index, or into any other scale appropriate for standardization purposes.

Metabolic response to halothane in piglets susceptible to malignant hyperthermia: an in vivo 31P-NMR study.

Using in vivo 31P-nuclear magnetic resonance spectroscopy, we studied the skeletal muscle metabolism of 17 anesthetized malignant hyperthermia-susceptible piglets and 25 control piglets during and after a halothane stress test. At rest, the phosphocreatine- (PCr) to-ATP ratio was 12% higher in the anesthetized piglets than in the control piglets, which may reflect a higher proportion of fast glycolytic fibers in the former. About 15 min of halothane administration sufficed to provoke onset of a reaction, which was characterized by a reciprocal drop in PCr and an increase in Pi with commencing intracellular acidosis. Halothane was withdrawn after a 20% drop in PCr. Within the next few minutes, intracellular pH dropped sharply and phosphomonoesters (PME) accumulated excessively. ATP was observed to decrease in 8 of the 17 animals. Halothane inhalation provoked a switch of metabolism toward glycolysis. Accumulation of PME suggests a mismatch between glycogenolysis and glycolysis. Despite severe acidification, glycolysis was not completely halted. Recovery of PCr and Pi started approximately 5 min after halothane withdrawal, with a longer time constant for recovery of the former. PME and intracellular pH aberrations lingered and started to recover later. Lost ATP was never restored within the observed recovery period of approximately 20 min.

A modulating effect of beta-endorphin on pigs' coping strategies during transport.

Pigs were selected at random from three genetic lines (homozygote halothane positive and negative, heterozygotes), and were transported twice. Before and after each transport, blood samples were taken from the jugular vein to measure plasma cortisol and beta-endorphin content. During each transport behaviour and heart rate of the pigs were measured. Descriptive statistics of behavioural, endocrinological and heart rate data provided no evidence for a predetermined idiosyncratic response pattern (i.e., active vs. passive) with respect to transport stress, nor an interaction from the halothane gene, nor an habituation effect. However, from the endocrinological point of view a potentially of passive and active coping strategy (i.e., high vs. low basal plasma cortisol content) was observed before transport. But classification of pigs according to an active and passive coping strategy was unrepeatable during successive transports, when based on heart rate and plasma cortisol content measurements during successive transports. This was explained by a potential modulating effect of beta-endorphin on the relationship between cortisol and heart rate.

Economic evaluation of national identification and recording systems for pigs in Belgium.

Four national identification and recording (I&R) systems for the Belgian pig industry were evaluated economically, using a computer simulation model. These systems were: (1) the previous system; (2) a revised system (based on the previous one); (3) a system based on electronic identification; (4) a system similar to (3) but which also allows electronic monitoring of individual pigs. The evaluation of the systems particularly concerned their use in the control of classical swine fever (CSF). Four factors have shown to be very influential in economic decision making with respect to I&R systems: (1) the economic losses per CSF epidemic; (2) the frequency of CSF epidemics; (3) the operational costs of the I&R system; (4) the possibility of additional use of the system besides CSF control. It was concluded that for the Belgian situation, replacement of the previous I&R system by the revised one is economically justifiable. Because of high operational costs, electronic identification systems are only economically feasible in very specific situations, e.g. when a higher degree of additional use is possible or with a relatively high frequency of CSF epidemics.