Prevalence and risk factors of Brachyspira spp. in pig herds with a history of diarrhoea in six European countries.

Swine dysentery and porcine intestinal spirochaetosis caused by Brachyspira (B.) hyodysenteriae and B. pilosicoli, respectively, are important diseases in swine production worldwide. The aim of this study was to assess the prevalence of both pathogens in farms with a history of diarrhoea within the last 12 months in Denmark, France, Germany, the Netherlands, Spain, and United Kingdom. In addition, risk factors for their prevalence and correlations between presence of different Brachyspira spp. and Lawsonia intracellularis were investigated. Therefore, faecal samples of 6355 nursery to finishing pigs out of 144 herds were sampled in 2017/2018 during a prevalence study on Lawsonia intracellularis, followed by polymerase chain reaction analysis for Brachyspira spp. detection. Herd prevalence differed significantly between countries, from 4.2% to 45.8% for B. hyodysenteriae and 8.3-87.5% for B. pilosicoli, respectively (p < 0.01). For the within-herd prevalence (in positive herds), these values ranged from 2.2% to 27.0% for B. hyodysenteriae and 3.3-50.8% for B. pilosicoli. Mixed infections occurred in 34.1% and 58.7% of B. hyodysenteriae positive samples with Lawsonia intracellularis or B. pilosicoli, respectively. In 43.2% of B. pilosicoli positive samples, Lawsonia intracellularis was detected simultaneously. Overall, nursery pigs were significantly less often positive for one of the pathogens than growing or finishing pigs (p < 0.001). The absence of gastrointestinal problems like diarrhoea, routine use of antimicrobials and well performed biosecurity measures were some of the factors associated with lower detection rate of Brachyspira spp. Surprisingly, deworming of different age categories also showed associations with the detection of Brachyspira spp. which, however, were not always equally directed, and therefore require further investigations. The only risk factor significant for both Brachyspira spp. was the median number of ≥ 30 nursery pigs per pen after weaning, compared to smaller group sizes. Both pathogens were detected with varying frequency between the six European countries. This should be considered in the probability of disease and in case of transnational transport, to prevent spread of pathogens. In addition, the frequent presence of mixed infections in some countries should be taken into account in diagnostics. The most important protective factors against Brachyspira spp. presence on farm are biosecurity measures, while potential new factors such as deworming still require further investigation.

Tail and ear necrosis in piglets of sows with increased weight loss over the suckling period.

INTRODUCTION: A farm belonging to a Swiss sow pool system reported increased cases of necrosis on the base of the tail or ears in their piglets. Therefore, herd examination was performed in February 2021, and it was found that about half of all examined litters included piglets with necrosis of different locations, and that the sows of these piglets were rather thin. Upon instruction, the farmer then documented the body condition score (BCS) and weight before farrowing and after weaning, and the number of liveborn piglets affected by necrosis of the tail or ear of the next four farrowing batches. In total, data of 97 sows with 1214 liveborn piglets were evaluated. Sows were retrospectively allocated into two groups: Those with piglets with ear and/or tail necrosis (NE), and those without (WN). Of the 97 litters, 40 included piglets with necrosis, with 28 of them having piglets only with tail necrosis, 8 only with ear necrosis, and 4 litters included piglets with both types of necrosis. The group NE lost significantly more weight and BCS points over the suckling period than the group WN, with a tendency of having a lower BCS after weaning (2,0 vs. 2,25/5,0). Blood samples of five sows were analyzed and tested positive for the Fusarium mycotoxin deoxynivalenol (DON). It could be possible that the sows previously consumed DON contaminated feed, which was then stored in their fat tissue, and released again into the blood stream during increased weight loss. Since DON can be transferred from the sow to her piglets during gestation or lactation, this release might have affected the piglets, leading to tail or ear necrosis. However, causative studies are needed to confirm this hypothesis.

INTRODUCTION: Une exploitation appartenant à un système suisse de pool de truies a signalé une augmentation des cas de nécrose à la base de la queue ou des oreilles chez ses porcelets. Par conséquent, un examen de l'effectif a été effectué en février 2021 et il a été constaté qu'environ la moitié de toutes les portées examinées comprenaient des porcelets présentant des nécroses à différents endroits et que les mères de ces porcelets étaient plutôt maigres. Sur instruction, l'éleveur a ensuite documenté la note d'état corporel (BCS) et le poids avant la mise bas et après le sevrage, ainsi que le nombre de porcelets nés vivants affectés par une nécrose de la queue ou de l'oreille des quatre lots de mise bas suivants. Au total, les données de 97 truies avec 1214 porcelets nés vivants ont été évaluées. Les truies ont été réparties rétrospectivement en deux groupes : Celles dont les porcelets présentaient une nécrose de l'oreille et/ou de la queue (NE), et celles qui n'en présentaient pas (WN). Sur les 97 portées, 40 comprenaient des porcelets atteints de nécrose, dont 28 uniquement avec une nécrose de la queue, 8 uniquement avec une nécrose de l'oreille et 4 avec les deux types de nécrose. Le groupe NE a perdu beaucoup plus de poids et de points BCS pendant la période d'allaitement que le groupe WN, avec une tendance à avoir un BCS plus faible après le sevrage (2,0 vs. 2,25/5,0). Les échantillons de sang de cinq truies ont été analysés et se sont révélés positifs pour la mycotoxine de Fusarium, le déoxynivalénol (DON). Il est possible que les truies aient consommé des aliments contaminés par le DON qui a ensuite été stocké dans leur tissu adipeux puis libéré dans le sang lors de la perte de poids. Comme le DON peut être transféré de la truie à ses porcelets pendant la gestation ou la lactation, cette libération pourrait avoir affecté les porcelets, entraînant une nécrose de la queue ou des oreilles. Cependant, des études causales sont nécessaires pour confirmer cette hypothèse.

Distribution, genetic heterogeneity, and antimicrobial susceptibility of Brachyspira pilosicoli in Swiss pig herds.

Brachyspira (B.) pilosicoli is a bacterium causing porcine intestinal spirochaetosis, a disease characterized by diarrhoea and depressed growth rates especially in nursery and fattening pigs. Knowledge of the epidemiology and antimicrobial susceptibility of this pathogen is limited. Therefore, the aim of this study was to analyse the distribution, genetic heterogeneity, and antimicrobial susceptibility of B. pilosicoli field isolates from Swiss pig farms. Faecal swabs of 693 animals originating from 156 herds were analysed for the presence of Brachyspira spp. using culture and polymerase chain reaction identification. Further characterisation was performed using multilocus sequence typing (MLST) and broth dilution antimicrobial susceptibility testing. With 52.6% positive herds, B. pilosicoli could be frequently isolated from herds with animals suffering from diarrhoea. In herds with animals without clinical signs of diarrhoea, detection was significantly less frequent with only 10.5% positive herds (p 0.001). Among 80 isolates used for typing, genetic heterogeneity was observed with 44 different sequence types (ST) which often differed from herd to herd. No predominant ST was observed. More than 73.0% of the 41 B. pilosicoli isolates analysed, showed minimal inhibitory concentration values above the wild type cut-off values for lincomycin, tylvalosin and/ or tylosin. For tiamulin, valnemulin and doxycycline, this was the case in 48.8%, 43.9% and 36.6%, respectively. In conclusion, a diverse population of B. pilosicoli exhibited decreased susceptibility to antimicrobials used against Brachyspira infections. Monitoring of resistance in Brachyspira spp. is highly recommended to support targeted use of antimicrobials in pigs.

Evaluation of different point-of-care tests to characterize the vaginal discharge of sows after parturition and parameters' correlation with subsequent reproductive performance.

The lochia is the physiological uterine discharge post-partum, whereas abnormal fluids are often indicators of puerperal disorders in sows, which negatively influence the further reproductive performance. The aim of the study was to characterize the vaginal discharge in sows employing simple and feasible tests and to correlate the evaluated parameters with the subsequent reproductive performance of these sows. The birth process of 48 clinically healthy free farrowing sows was monitored and several parameters characterizing the vaginal discharge such as total amount, colour, amount of cells (somatic cell count) and cell characteristics (cytology) were collected daily from first to fifth day after parturition. Finally, the reproductive performance of the following gestation was evaluated and compared to the characteristics of the lochia. The amount of vaginal discharge was significantly increased on the second (p < 0.01), third (p = 0.019) and fourth (p = 0.011) day post-partum compared to day one. Furthermore, a decrease in the percentage of neutrophilic granulocytes from day one to three (p = 0.038), four (p = 0.038) and five (p = 0.048) post-partum was observed. The percentage of neutrophilic granulocytes in the yellowish vaginal discharge was increased compared to whitish (p = 0.02) or clear (p = 0.027) vaginal discharge. In addition, obstetrics (p = 0.003) and an increased farrowing duration (p = 0.017) significantly increased the amount of vaginal discharge. Sows with a high amount of vaginal discharge had a significant higher body temperature than sows with no (p = 0.014) or low amount (p < 0.01) of vaginal discharge. No correlation was detected between the evaluated parameters of the lochia and the subsequent reproductive performance. It is hypothesised that the amount of vaginal discharge alone is not a predictor for the performance of sows during their next gestation. However, it might serve as indicator for acute endometritis. In summary, the different parameters of the vaginal discharge determined by means of point-of-care tests might be useful to strengthen a presumptive diagnose of endometritis in sows during the first five days after parturition.

Effect of housing conditions, management procedures and traits of the external male reproductive tract on the sexual behaviour of natural mating boars.

Although artificial insemination in pig production is widespread, many farms rely on natural mating (NM). For NM to be successful, adequate sexual behaviour and a sufficient libido level in boars is crucial for appropriate reproductive performance. Therefore, this observational study evaluated the libido level of 59 boars of different breeds used for NM by a scoring system ranging from 0 (no libido) to a maximum of 23 points (perfect libido) and analysed their general and andrological health as well as housing and management factors influencing the libido. The boars showed a mean libido score of 16.7 (SD ± 2.3). Crossbreed (median: 17.5, min: 14.0, max: 21.0) (p < 0.01) and Landrace (median: 17.5, min: 17.0, max: 21.0) (p < 0.05) boars showed significantly higher libido scores compared to Piétrain boars (median: 14.0, min: 13.0, max: 17.0). A non-slippery mating area was found to be positively associated with libido (p < 0.05), whereas disorders such as lameness showed a negative correlation (p < 0.01). In winter, significantly higher libido values (median: 17.0, min: 14.0, max: 21.0) were recorded compared to spring (median: 16.0, min: 11.0, max: 21.0) (p < 0.05). In addition, high number of supports by farmers during natural mating and frequency of use for NM and for stimulation of artificially inseminated sows did not negatively influence the libido score. No significant correlation between the satisfaction of the farmer about the libido level of the boars and the evaluated libido score was detected. This is the first study investigating the effect of housing conditions and management procedures on the libido of boars used for NM under field conditions. The findings may therefore help to establish a successful mating management for herds applying NM on a regular basis. A systematic evaluation of the libido score is needed to detected boars with low libido levels, because it is often overlooked by the farmers. Moreover, genetics, general health condition and flooring in mating areas turned out to be critical parameters that influence the libido score of boars used for NM and therefore should be considered when examining natural mating on farm.

Application of an economic calculator to determine the cost of porcine reproductive and respiratory syndrome at farm-level in 21 pig herds in Germany.

BACKGROUND: Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) continues to be a major economic issue for the swine industry worldwide, not only due to acute outbreaks but also endemic infections. PRRS disease severity and consequently financial losses can vary greatly between endemically infected farms and estimation of damage is challenging. This study aimed to assess the economic effect of PRRS in a systematic way at individual farm-level for endemically infected herds, using a PRRS cost simulation tool. In total 21 German sow herds with endemic PRRSV infection were investigated. Data on health and production performance, farm management and environment to be fed into the calculator was collected on each farm, and blood samples taken to confirm the PRRSV status. RESULTS: All study farms experienced a significant loss attributable to PRRS. The median farm budget across all farms was - 31 € per sow and year, compared to a median simulated farm budget of 248 € if these farms had been PRRSV negative. The median total loss attributable to PRRS was 74,181 € per farm per year, corresponding to a median total loss per sow and year of 255 €. The impact of PRRS on farm profits was - 19.1% on average and - 41% in the worst case. CONCLUSIONS: The calculated losses give a good hint of the economic damage due to PRRS for the pig industry. Even in endemically infected farms, farmers face a non-negligible damage and profit from a concerted PRRS control. The calculator has proven itself in the field to render a valid estimation of losses due to PRRS in endemically infected farms.

Influence of different sow traits on the expulsion and characteristics of the placenta in a free farrowing system.

The last phase of parturition is the detachment and expulsion of the placentas and should not exceed a duration of 4 h after the birth of the last piglet. At present, only a small amount of information is available about factors influencing the expulsion of the placenta, especially in sows accommodated in free farrowing systems. This study aimed at investigating the influence of sow traits on placenta expulsion in a free farrowing system in Switzerland. In this study, 48 crossbred sows were included and the following traits of the sows were investigated: Backfat thickness, birth induction with at least 116 days of gestation with prostaglandin F2α, placenta parts and weight, placental efficiency (quotient of litter weight and placental weight) and expulsion of the first placenta part in relation to the last piglet. In addition, the farrowing process and litter parameters were recorded. The piglet expulsion duration (260.3 ± 199.5 min) and placenta expulsion duration (388.7 ± 300.2 min) were positively correlated (p = 0.001). Sows that expelled the first placenta part simultaneously with the last piglet or even before the last piglet was born showed a significantly prolonged piglet expulsion duration in comparison to sows that expelled the first placenta part after the last piglet was born (305 ± 216 min vs. 139.0 ± 34.9 min; p < 0.01). Sows with 2-4 placenta parts had a significantly shorter farrowing (292.91 ± 117.92 min) and placenta expulsion duration (160.73 ± 104.00 min) than sows with 5-7 placenta parts (634.63 ± 330.79 min farrowing duration; 460.77 ± 337.32 min placenta expulsion duration) and sows with 8-10 placenta parts (599.00 ± 138.20 min farrowing duration; 438.43 ± 117.98 min placenta expulsion duration) (p < 0.01). Sows with placental efficiency <5 were characterized by a significantly higher number of liveborn piglets compared to sows with a placental efficiency ≥5 (17.1 ± 2.7 piglets vs. 13.6 ± 2.8 piglets; p = 0.002). This is the first study that evaluated the placental characteristics in a free farrowing system and compared it with specific sow traits. Especially, the expulsion of the first placenta and the number of placenta parts could be a reliable parameter to detect sows with obstetric problems and therefore enable improvement sow and piglet health.

Risk factors for tail lesions in undocked fattening pigs reared on Swiss farms.

INTRODUCTION: Tail lesions caused by tail biting are a major welfare and economic concern in fattening pigs. The aims of this study were to describe the prevalence and incidence of tail lesions in undocked pigs on individual animal level during the fattening period, to elucidate potential risk factors associated with tail lesions, and to describe the stockpersons' attitudes towards tail biting on Swiss farms. Thirty-eight farms were visited three times during the fattening period (beginning, mid-point, end). During each farm visit, tail lesions were scored on 30-126 individually marked pigs per farm (total: 2209 pigs), information on potential risk factors for tail lesions was recorded, and a standardized interview with the farmer was conducted to explore his/her opinion on tail biting. Potential risk factors were defined by indices when adequate, and their influence on the occurrence of tail lesions was analyzed using mixed effects logistic regression models. During the first and the second half of the fattening period, on average 14,1 and 15,4 pigs, respectively, out of 100 developed new tail lesions or aggravation of old lesions. The risk for new or aggravated tail lesions increased with higher scores for a «disease index¼ and with increasing group size, and it decreased with higher space allowances and with restrictive compared with ad libitum feeding. The prevalence of tail lesions on arrival was not associated with the incidence of tail lesions in the first and the second half of the fattening period, neither at farm level nor at pen level. In the interviews, farmers expressed their interest in getting professional advice on how to reduce tail biting on their farms. In conclusion, our study identified several risk factors for tail lesions in undocked fattening pigs indicating that the incidence of tail lesions could be reduced by improving animal health and housing conditions.

INTRODUCTION: Les lésions de la queue causées par morsure sont un problème majeur de bien-être et d'économie chez les porcs d'engraissement. Les objectifs de cette étude étaient de décrire la prévalence et l'incidence des lésions de la queue pendant la période d'engraissement chez les porcs non écaudés au niveau de chaque animal, d'élucider les facteurs de risque potentiels associés aux lésions de la queue et de décrire les attitudes des éleveurs à l'égard des morsures de queue dans les exploitations suisses. Trente-huit exploitations ont été visitées trois fois pendant la période d'engraissement (début, mi-parcours, fin). Lors de chaque visite, les lésions de la queue ont été notées sur 30 à 126 porcs marqués individuellement par l'exploitant (total: 2209 porcs), des informations sur les facteurs de risque potentiels de lésions de la queue ont été enregistrées et un entretien standardisé avec l'éleveur a été mené pour connaitre son avis sur les morsures de queue. Les facteurs de risque potentiels ont été définis par des indices lorsqu'ils étaient adéquats et leur influence sur la survenue des lésions caudales a été analysée à l'aide de modèles de régression logistique à effets mixtes. Pendant la première et la deuxième moitié de la période d'engraissement, en moyenne 14,1 et 15,4 porcs, respectivement, sur 100 ont développé de nouvelles lésions de la queue ou une aggravation d'anciennes lésions. Le risque de nouvelles lésions de la queue ou d'aggravation augmentait avec des scores plus élevés pour un «indice de maladie¼ et avec l'augmentation de la taille du groupe et il diminuait avec des allocations d'espace plus élevées et avec une alimentation restrictive par rapport à l'alimentation à volonté. La prévalence des lésions de la queue à l'arrivée n'était pas associée à l'incidence des lésions de la queue dans la première et la seconde moitié de la période d'engraissement, ni au niveau de l'exploitation ni au niveau des boxes. Dans les entretiens, les agriculteurs ont exprimé leur intérêt à obtenir des conseils professionnels sur la façon de réduire les morsures de queue dans leurs exploitations. En conclusion, notre étude a identifié plusieurs facteurs de risque de lésions de la queue chez les porcs d'engraissement non écaudés indiquant que l'incidence des lésions de la queue pourrait être réduite en améliorant la santé animale et les conditions de logement.

Ultrasonographic examination of postpartum uterine involution in sows.

Physiological uterine involution during the puerperium period is essential for sow reproductive health. Uterine involution in sows has mainly been described using macroscopic and histological examination after slaughter. The aim of this study, therefore, was to describe the continuous regression of uterine diameter from day 2-14 after parturition and on the day before weaning using ultrasonography in sows housed in a free farrowing system and in farrowing crates. Diameter of three uterine cross-sections was measured at 24 -hs intervals in 46 sows housed in a free farrowing system in Switzerland and 49 sows housed in farrowing crates in Germany. Overall, there was continuous regression of uterine diameter during the lactation period in both groups. Median diameter of the uterus decreased from 32.4 mm (min: 18.6 mm, max: 52.3 mm) on day 2-9.0 mm (min: 7.6 mm, max: 12.7 mm) on the day before weaning (on average 30 days p.p.) in sows housed in free farrowing systems. Median diameter of the uterus of sows in farrowing crates decreased from 38.5 mm on day 2 (min: 21.6 mm, max: 56.3 mm) to 10.1 mm (min: 8.8 mm, max: 13.6 mm) the day before weaning (on average 29 days p.p.). Interestingly, parity, obstetrical intervention and administration of oxytocin was not associated with the decrease of uterine diameter during the study period. In summary, the ultrasonic examination is a suitable method to evaluate diameter of the uterus during the puerperium period in sows and to describe uterine involution in vivo.

[Retrospective study on the eradication of Swine Dysentery (Brachyspira hyodysenteriae) in Switzerland]. / Retrospektive Studie zur Sanierung von Beständen mit Schweinedysenterie (Brachyspira hyodysenteriae) in der Schweiz.

INTRODUCTION: The eradication of Swine Dysentery (infection with Brachyspira hyodysenteriae) within farm populations is extremely complex and its success is significantly linked to the compliance of pig farmers performing the onsite eradications, emphasizing the importance of their motivation. The present study focuses on the motivation and satisfaction of Swiss pig farmers concerning eradication of Swine Dysentery on their farms and has the intention of generating data to establish a basis for decision-making regarding future eradications. A structured survey was conducted on 68 Swiss pig farms where an eradication of Swine Dysentery had already taken place. The data collected were then statistically analyzed. Of the study's population, 50 (73.5%) farms underwent eradication using the total depopulation method and 18 (26.5%) farms conducted an eradication process using the partial depopulation method; both in accordance to the guidelines of Switzerland's Pig Health Service (SUISAG Schweinegesundheitsdienst; SGD). When asked about the driving factors behind their decision to perform the eradications, owners cited their own interest (57.4%; 39/68) (primarily due to financial aspects (38.5%; 15/39)) or external pressure (42.7%; 29/68) (predominantly through marketers as well as through the health status assigned by the SGD (each 11/29)). The duration of the eradication on farms differed significantly and costs varied considerably within the different production types as well as the type of eradication performed. Utilized means and processes for eradication were the same (drugs, disinfectant for manure) or much alike (e.g. emptying of the pigpens) however stock-specific and individual variations were exhibited. The majority of the interviewed livestock owners were motivated to perform the eradication (86.6%; 58/67), satisfied with having performed the eradication and satisfied with the outcome of the eradication (89.7%; 61/68). The cost efficiency of the farms (54.4%; 37/68) and the health status of the herds (63.2%; 43/68) were perceived as having improved and the usage of drugs having diminished (59.7%; 40/67) post eradication. The effort of an eradication was described as acceptable to too great. The study showed herd eradication of Swine Dysentery to be perceived as mainly positive. However, effort as well as costs are felt to be considerable and could, therefore, provide the most important starting point to increasing the willingness of pig owners to perform eradications.

INTRODUCTION: L'assainissement d'exploitations avec de problèmes de dysenterie porcine (infection à Brachyspira hyodysenteriae) peut prendre beaucoup de temps et son succès est étroitement lié à l'observance des personnes qui l'exécutent. C'est pourquoi les éleveurs de porcs doivent être motivés pour effectuer cette lutte. La présente étude a notamment porté sur la motivation et la satisfaction des détenteurs suisses de porcs en ce qui concerne l'assainissement de la dysenterie porcine afin de générer des données et, partant, des aides à la décision pour de futures mesures de lutte. Pour cela, des données ont été collectées au moyen d'un entretien structuré et analysées statistiquement dans 68 exploitations suisses après un assainissement complet de la dysenterie. Dans ces exploitations, 50 assainissements totaux (73.5%) et 18 assainissements partiels (26,5%) ont été effectués conformément aux directives du Service sanitaire porcin suisse (SUISAG SGD). L'intérêt propre (57,4%, 39/68) (principalement dû aux aspects financiers (38,5%; 15/39)) et la pression externe (42,7%; 29/68) (principalement par statut SGD ou par les négociants (chacun pour 11/29)) étaient les raisons de l'assainissement. La durée de l'assainissement et les coûts variaient considérablement selon les types de production de même que selon les types d'assainissement. Dans le cadre de l'assainissement, les moyens utilisés et les processus étaient les mêmes (médicaments, désinfectant de fumier) respectivement étaient similaires (par exemple, la vidange des écuries) mais présentait des variations individuelles spécifiques à l'exploitation. La majorité des propriétaires d'animaux interrogés étaient motivés à un assainissement (86,6%, 58/67) et étaient également satisfaits de l'avoir fait (97,1%, 66/68) et du résultat (89,7%, 61/68). Après l'assainissement, la rentabilité (54,4%; 37/68) et la santé du cheptel (63,2%; 43/68) ont été jugées subjectivement meilleures et la consommation de médicaments (59,7%; 40/67) inférieure. Le coût de l'assainissement était, selon le type de production, considéré comme justifié jusqu'à élevé. On a pu montrer que l'assainissement de la dysenterie porcine est généralement évalué positivement. Cependant, les efforts et les coûts sont considérables et représentent des points de départ possibles pour optimiser la volonté des éleveurs de porcs.

Isolation of Brachyspira hyodysenteriae from a crow (Corvus corone) in close proximity to commercial pigs.

The aim of this study was to determine whether crows (Corvus corone) can harbour Brachyspira hyodysenteriae, the cause of swine dysentery, and whether the organism carried by crows is related to strains infecting pigs. B. hyodysenteriae was isolated from one crow in close proximity to two pig farms in Switzerland. This isolate, along with five isolates of B. hyodysenteriae from one of the farms, belonged to sequence type (ST) 66 using multilocus sequence typing. This finding suggests that crows are potential vectors of B. hyodysenteriae, but further studies will be necessary to clarify the role of crows in the epidemiology of this organism.

Modelling the economic efficiency of using different strategies to control Porcine Reproductive & Respiratory Syndrome at herd level.

PRRS is among the diseases with the highest economic impact in pig production worldwide. Different strategies have been developed and applied to combat PRRS at farm level. The broad variety of available intervention strategies makes it difficult to decide on the most cost-efficient strategy for a given farm situation, as it depends on many farm-individual factors like disease severity, prices or farm structure. Aim of this study was to create a simulation tool to estimate the cost-efficiency of different control strategies at individual farm level. Baseline is a model that estimates the costs of PRRS, based on changes in health and productivity, in a specific farm setting (e.g. farm type, herd size, type of batch farrowing). The model evaluates different intervention scenarios: depopulation/repopulation (D/R), close & roll-over (C&R), mass vaccination of sows (MS), mass vaccination of sows and vaccination of piglets (MS + piglets), improvements in internal biosecurity (BSM), and combinations of vaccinations with BSM. Data on improvement in health and productivity parameters for each intervention were obtained through literature review and from expert opinions. The economic efficiency of the different strategies was assessed over 5 years through investment appraisals: the resulting expected value (EV) indicated the most cost-effective strategy. Calculations were performed for 5 example scenarios with varying farm type (farrow-to-finish - breeding herd), disease severity (slightly - moderately - severely affected) and PRRSV detection (yes - no). The assumed herd size was 1000 sows with farm and price structure as commonly found in Germany. In a moderately affected (moderate deviations in health and productivity parameters from what could be expected in an average negative herd), unstable farrow-to-finish herd, the most cost-efficient strategies according to their median EV were C&R (€1'126'807) and MS + piglets (€ 1'114'649). In a slightly affected farrow-to-finish herd, no virus detected, the highest median EV was for MS + piglets (€ 721'745) and MS (€ 664'111). Results indicate that the expected benefits of interventions and the most efficient strategy depend on the individual farm situation, e.g. disease severity. The model provides new insights regarding the cost-efficiency of various PRRSV intervention strategies at farm level. It is a valuable tool for farmers and veterinarians to estimate expected economic consequences of an intervention for a specific farm setting and thus enables a better informed decision.

Cost of porcine reproductive and respiratory syndrome virus at individual farm level - An economic disease model.

Porcine reproductive and respiratory syndrome (PRRS) is reported to be among the diseases with the highest economic impact in modern pig production worldwide. Yet, the economic impact of the disease at farm level is not well understood as, especially in endemically infected pig herds, losses are often not obvious. It is therefore difficult for farmers and veterinarians to appraise whether control measures such as virus elimination or vaccination will be economically beneficial for their farm. Thus, aim of this study was to develop an epidemiological and economic model to determine the costs of PRRS for an individual pig farm. In a production model that simulates farm outputs, depending on farm type, farrowing rhythm or length of suckling period, an epidemiological model was integrated. In this, the impact of PRRS infection on health and productivity was estimated. Financial losses were calculated in a gross margin analysis and a partial budget analysis based on the changes in health and production parameters assumed for different PRRS disease severities. Data on the effects of endemic infection on reproductive performance, morbidity and mortality, daily weight gain, feed efficiency and treatment costs were obtained from literature and expert opinion. Nine different disease scenarios were calculated, in which a farrow-to-finish farm (1000 sows) was slightly, moderately or severely affected by PRRS, based on changes in health and production parameters, and either in breeding, in nursery and fattening or in all three stages together. Annual losses ranged from a median of € 75'724 (90% confidence interval (C.I.): € 78'885-€ 122'946), if the farm was slightly affected in nursery and fattening, to a median of € 650'090 (90% C.I. € 603'585-€ 698'379), if the farm was severely affected in all stages. Overall losses were slightly higher if breeding was affected than if nursery and fattening were affected. In a herd moderately affected in all stages, median losses in breeding were € 46'021 and € 422'387 in fattening, whereas costs were € 25'435 lower in nursery, compared with a PRRSV-negative farm. The model is a valuable decision-support tool for farmers and veterinarians if a farm is proven to be affected by PRRS (confirmed by laboratory diagnosis). The output can help to understand the need for interventions in case of significant impact on the profitability of their enterprise. The model can support veterinarians in their communication to farmers in cases where costly disease control measures are justified.

Multicystic degeneration of the Cowper's gland in a Large White boar.

The present report describes a case of multicystic degeneration of the Cowper's gland in a 1.3-year-old purebred Large White intact boar with reduced fertility in Switzerland. Based on the case history, a general physical examination, an andrological investigation and a transrectal ultrasonography combined with a subsequent thorough pathological examination including histology a multicystic degeneration of the Cowper's gland were diagnosed. The case indicates that cystic degeneration of the bulbourethral gland should be contemplated in the differential diagnoses of andrological disorders even though it has not been described in pigs so far. While selecting breeding boars, a morphological check of the bulbourethral gland can be performed, since degeneration of the gland would potentially have an impact on future fertility.

Occurrence of Brachyspira hyodysenteriae in multiplier pig herds in Switzerland.

OBJECTIVE: This research was aimed to determine the occurrence of Brachyspira (B.) hyodysenteriae in Swiss multiplier pig herds. MATERIALS AND METHODS: In a pilot study a direct real-time polymerase chain reaction (PCR) method for B. hyodysenteriae was compared to culture followed by PCR on 106 samples from three herds. Subsequently 40 multiplier herds were epidemiologically characterized and analysed for the presence of B. hyodysenteriae using direct PCR on 1412 rectal swabs. For external validation 20 swabs obtained from two positive conventional herds were analysed. RESULTS: The comparison of direct PCR with culture followed by PCR resulted in a moderate agreement (kappa index: 0.58). In the two conventional herds, 35% of the samples (7/20) tested positive. Samples from 39 multipliers tested negative. In one multiplier herd, 25% (9/36) of the samples tested PCR positive. Risk factors in the multiplier herd may have been rodents or birds, but not pig purchase. CONCLUSION AND CLINICAL RELEVANCE: B. hyodysenteriae have been detected in a Swiss multiplier herd, which underlines the threat of potential spread by replacement pigs. Consequently, a Brachyspira monitoring programme was established for Swiss multiplier herds.

An Outbreak of Porcine Reproductive and Respiratory Syndrome Virus in Switzerland Following Import of Boar Semen.

An outbreak of porcine reproductive and respiratory syndrome virus (PRRSV) occurred in November 2012 in Switzerland (CH), traditionally PRRSV-free. It was detected after a German boar stud informed a semen importer about the detection of PRRSV during routine monitoring. Tracing of semen deliveries revealed 26 Swiss sow herds that had used semen from this stud after its last negative routine monitoring and 62 further contact herds. All herds were put under movement restrictions and examined serologically and virologically. As a first measure, 59 sows from five herds that had previously been inseminated with suspicious semen were slaughtered and tested immediately. Investigations in the stud resulted in 8 positive boars with recent semen deliveries to CH (Seven with antibodies and virus, one with antibodies only). In one boar out of six tested, virus was detected in semen. Of the 59 slaughtered sows, five from three herds were virus-positive. In one herd, the virus had spread, and all pigs were slaughtered or non-marketable animals euthanized. In the remaining herds, no further infections were detected. After confirmatory testings in all herds 3 weeks after the first examination gave negative results, restrictions were lifted in January 2013, and Switzerland regained its PRRSV-free status. The events demonstrate that import of semen from non-PRRS-free countries--even from negative studs--poses a risk, because monitoring protocols in boar studs are often insufficient to timely detect an infection, and infections of sows/herds occur even with low numbers of semen doses. The outbreak was eradicated successfully mainly due to the high disease awareness of the importer and because immediate actions were taken before clinical or laboratory diagnosis of a single case in the country was made. To minimize the risk of an introduction of PRRSV in the future, stricter import guidelines for boar semen have been implemented.

Attitudes and Beliefs of Pig Farmers and Wild Boar Hunters Towards Reporting of African Swine Fever in Bulgaria, Germany and the Western Part of the Russian Federation.

This study investigated the attitudes and beliefs of pig farmers and hunters in Germany, Bulgaria and the western part of the Russian Federation towards reporting suspected cases of African swine fever (ASF). Data were collected using a web-based questionnaire survey targeting pig farmers and hunters in these three study areas. Separate multivariable logistic regression models identified key variables associated with each of the three binary outcome variables whether or not farmers would immediately report suspected cases of ASF, whether or not hunters would submit samples from hunted wild boar for diagnostic testing and whether or not hunters would report wild boar carcasses. The results showed that farmers who would not immediately report suspected cases of ASF are more likely to believe that their reputation in the local community would be adversely affected if they were to report it, that they can control the outbreak themselves without the involvement of veterinary services and that laboratory confirmation would take too long. The modelling also indicated that hunters who did not usually submit samples of their harvested wild boar for ASF diagnosis, and hunters who did not report wild boar carcasses are more likely to justify their behaviour through a lack of awareness of the possibility of reporting. These findings emphasize the need to develop more effective communication strategies targeted at pig farmers and hunters about the disease, its epidemiology, consequences and control methods, to increase the likelihood of early reporting, especially in the Russian Federation where the virus circulates.