Heterologous Challenge with PRRSV-1 MLV in Pregnant Vaccinated Gilts: Potential Risk on Health and Immunity of Piglets.

The objective of the present study was to evaluate the potential risks of the four commercial PRRS-1 MLV vaccines in pregnant vaccinated gilts at the last stage of gestation under field conditions. The study was conducted at four pig farms, including 25 gilts from each farm (25 × 4 = 100 gilts), which were equally allocated to five different study groups. A PRRS-1 MLV vaccination was applied on the 100th day of their pregnancy with the different commercial vaccines that are available in the Greek market. The results indicated virus congenital infection and viremia in piglets (20/200 = 10% PRRSV infected piglets), and detection of PRRSV-specific antibodies (181/200 = 90.5% piglets found with PRRSV antibodies). The subsequent phylogenetic analyses revealed high percentages of similarity between the PRRSV-1 strain detected in infected litters and the PRRSV-1 vaccine strain to which the study gilts had been previously exposed to. Health status analyses of trial piglets resulted in differences between litters from vaccinated sows and litters from non-vaccinated sows at 110th day of gestation as regards the number of weak-born piglets, mummies, and piglets with splay-leg and/or respiratory symptoms. The current study's results indicate several potential dangers of the PRRS MLV vaccination in late gestation.

Report on the First African Swine Fever Case in Greece.

African swine fever (ASF) poses a major threat to swine health and welfare worldwide. After several European countries have reported cases of ASF, Greece confirmed officially the first positive case on 5 February 2020. The owner of a backyard farm in Nikoklia, a village in Serres regional unit, Central Macedonia, reported a loss of appetite, weakness, dyspnea, and the sudden death of 6 domestic pigs. Necropsy was performed in one gilt and findings were compatible with acute to subacute septicemic disease. Predominantly, hyperemic enlargement of spleen and lymph node enlargement and/or hemorrhage were observed. Description of vague clinical signs by the farmer suggested a limited resemblance to ASF-acute infection. However, the disease could not be ruled out once septicemic condition including splenomegaly, was diagnosed macroscopically at necropsy. In addition, considering the farm's location near to ASF protection zones, a further diagnostic investigation followed. Confirmation of the disease was obtained using a series of diagnostic tests on several tissue samples. Further clinical, molecular, and epidemiologic evaluation of the farm was performed. According to the contingency plan, authorities euthanized all 31 pigs on the farm, whilst blood testing revealed ASF virus infection. Further emergency measures were implemented to contain the spread of the disease.

Effect of Boar Sperm Proteins and Quality Changes on Field Fertility.

This study aimed to evaluate boar sperm characteristics and proteins, in relation to their importance regarding in vivo fertility. Sixty-five ejaculates were used and 468 sows (parity ≥ 2) were inseminated. Sperm CASA kinetics, morphology, viability, DNA fragmentation, mitochondrial membrane potential, sperm membrane biochemical activity (HOST) and sperm proteins (Heat Shock Protein 90-HSP90, glutathione peroxidase-5-GPX5, Osteopontin 70-OPN70) were assessed and related to field fertility (number of live-born piglets-NLBP, litter size ≥ 12 piglets-LS, farrowing rate-FR). Statistical analysis was conducted with simple and multiple regression models. Simple regression analysis showed that immotile sperm (IM) significantly affected the NLBP and LS, explaining 6.7% and 6.5% of their variation, respectively. The HOST positive spermatozoa significantly affected the NLBP and LS, explaining 24.5% and 7.8% of their variation, respectively. Similarly, sperm with activated mitochondria significantly affected the NLBP, explaining 13.5% of its variation. Moreover, the OPN70 affected LS and FR, explaining 7.5% and 10.8% of their variation, respectively. Sperm GPX5 protein affected FR, explaining 6.7% of its variation. Multiple regression analysis showed that the combination of IM and/OPN70 explains 13.0% of the variation regarding LS, and the combination of GPX5 and OPN70 explains 13.6% of the variation regarding FR. In conclusion, the estimation of parameters IM, membrane biochemical activity, mitochondrial membrane potential, OPN and GPX5 can provide useful information regarding semen doses for field fertility.

Prevalence and Risk Factors of Intestinal Parasite Infections in Greek Swine Farrow-To-Finish Farms.

Intestinal parasites, helminths, and protozoa challenge health and welfare of pigs and deteriorate the sustainability of swine farms leading to monetary losses. A multicentric survey was conducted for approximately one year. Overall, 1150 fecal samples were collected from eight intensive farms in Greece at regular intervals and examined by flotation and Ziehl-Neelsen techniques. Age, season, and time of last recorded antiparasitic treatment were assessed as possible risk factors using binary regression models. The overall prevalence of intestinal parasitism in pigs was 44.7%. The most frequently detected parasites in the studied population were the protozoa Balantidium coli (37.8%), followed by Entamoeba spp. (8.3%), Cystoisospora suis (6.0%), and the nematodes Ascaris suum (3.7%), Trichuris suis (2.5%), and Oesophagostomum spp. (1.4%). Distribution of intestinal parasites in different age groups was as expected. In autumn, the prevalence of Balantidium coli infection enhanced whereas the prevalence of Entamoeba spp. and Cystoisospora suis infections increased in spring. Time of last recorded antiparasitic treatment influenced Balantidium coli and Trichuris suis infection levels. Our results demonstrated that swine intestinal parasitism in intensive farms of Greece seems to be relatively common and highlighted the importance of proper laboratory examinations, as well as the need for tailored made control programs.

A randomized controlled study on the efficacy of a novel combination vaccine against enzootic pneumonia (Mycoplasma hyopneumoniae) and porcine Circovirus type 2 (PCV2) in the presence of strong maternally derived PCV2 immunity in pigs.

BACKGROUND: Mycoplasma hyopneumoniae (M. hyo) and Porcine Circovirus Type 2 (PCV2) are major pathogens that cause significant health problems in swine worldwide. Maternal derived immunity (MDI) has been suggested as a significant immediate defence factor for newborn piglets and may interfere with piglet's vaccination-induced immunity. The study aimed to assess the efficacy of a novel combination vaccine (consisting of PCV2 subunits and inactivated M. hyo strain J), against PCV2 and M. hyo natural infection [Porcilis® PCV M Hyo (MSD Animal Health, Boxmeer, the Netherlands)], in the presence of strong maternally derived PCV2 immunity (antibody titre averaged 11.08 log2), under field conditions. The study was performed according to a controlled, randomized and blinded design in a Greek swine unit with Enzootic Pneumonia (EP) and subclinical PCV2 infection. In total, 600 healthy three-week-old suckling piglets were allocated randomly, either to treatment (vaccinated with the test product) or control group (injected with sterile buffered saline). RESULTS: Vaccination significantly reduced the severity of lung lesions at slaughter (lesions of cranio-ventral pulmonary consolidation) (P < 0.001). The overall mean lung lesion score (LLS) was 9.6 in the vaccinated group and 12.2 in controls. The level of PCV2 viraemia was significantly reduced in vaccinated pigs. Furthermore, 25 g higher average daily weight gain (ADWG) was observed during the finishing phase (P < 0.001) and 18 g greater ADWG overall (P < 0.001). CONCLUSIONS: Results of LLS, PCV2 viremia and ADWG support the test product's efficacy in the face of strong maternally derived PCV2 immunity.

Cross-Sectional Serosurvey and Risk Factors Associated with the Presence of Toxoplasma gondii Antibodies in Pigs in Greece.

INTRODUCTION: Toxoplasmosis is a worldwide reported zoonotic infection caused by the protozoon Toxoplasma gondii. Pigs may become infected by ingesting feed or water contaminated with cat faeces, by cannibalism, and/or by eating infected rodents. T. gondii infected edible tissues of pigs are a source of infection for humans. This study was undertaken to detect seropositivity of pigs against T. gondii and identify possible risk factors as well as to compare two serological methods. METHODS: A total of 609 blood samples were collected from 10% of the sows from 65 pig farms located in mainland Greece. Information about the geographical location, size, and biosecurity level of the herd was recorded. Samples were tested for the presence of antibodies against T. gondii employing the indirect fluorescent antibody test and the enzyme-linked immunosorbent assay. RESULTS: Twenty-six positive samples were detected (4.3%) in 17 out of the 65 farms tested (26.2%). The average seroprevalence in affected herds was 26.8% (95% confidence interval 21.0-32.6%). Among the categorical data evaluated, the biosecurity level (odds ratio 0.17, p < 0.01) and the geographical characteristics (odds ratio 13.55, p < 0.05) significantly affected the presence of toxoplasmosis in the herd. Toxoplasmosis was recorded in significantly higher percentages in mountainous farms as compared to lowlands (p < 0.05) and in those with poor biosecurity levels than in those with very good (p < 0.05). A very good agreement (κ = 0.958) was observed between the two serological methods. CONCLUSION: The presence of antibodies in pigs is indirect information on the risk of the infection and an indication of the necessity of biosecurity measures to be taken in order to control infection at least in the areas at highest risk.

Field efficacy study of a novel ready-to-use vaccine against mycoplasma hyopneumoniae and porcine circovirus type 2 in a Greek farm.

BACKGROUND: The primary objective of this study was to assess the efficacy, under field conditions, of a novel ready-to use Mycoplasma hyopneumoniae (M hyo) and Porcine circovirus type 2 (PCV2) combination vaccine given to piglets as one vaccination (1-shot) at 3 weeks of age. The study was carried out according to a controlled, randomised, and blinded design in a Greek pig herd with clinical M. hyo and subclinical PCV2 infection. Moreover, based on serology at the time of vaccination, the average PCV2 titre was 9.15 log2 and represented the level of maternally derived antibodies (MDA). In total 602 healthy suckling piglets, originating from 4 weekly farrowing batches were allocated randomly, within litters, to one of two groups. The pigs in one group were vaccinated with the test product and the other pigs were injected with saline. RESULTS: Vaccination significantly reduced lesions of craneo-ventral pulmonary consolidation in vaccinated group [expressed as lung lesion score (LLS)] (Mixed model ANOVA: p < 0.0001). The mean LLS was 17.1 in the controls and 10.6 in the treatment group, respectively. The average daily weight gain (ADWG) during the finishing (54 g better in the treatment group) and whole study period (34 g better in vaccinated animals) was significantly greater in vaccinated than control pigs. The vaccinated pigs had a significant reduction of PCV2 viraemia when compared with the controls. CONCLUSIONS: The test product was considered effective in the face of average MDA, based on significantly reduced severity of LLS and PCV2 viral load, as well as improved ADWG in vaccinated versus control pigs.

Effect of a natural feed additive (Macleaya cordata), containing sanguinarine, on the performance and health status of weaning pigs.

The aim of this study was to investigate the efficacy of Sangrovit(®) , a plant-derived feed additive, given throughout the nursery stage via feed at 15 ppm and 50 ppm, on the health status and performance of weaners against negative controls. In a 900-sow farrow-to-finish farm, a total of 864 piglets were divided into three groups: (i) negative controls (NC); (ii) Sang 15: same feed as NCs, plus 15 g Sangrovit(®) /t of feed; (iii) Sang 50: same feed as NCs plus 50 g Sangrovit(®) /t of feed. The results indicated that administration of 50 ppm(-) Sangrovit(®) had the most beneficial effects on growth performance in weaning pigs. Specifically there was increase of body weight and average daily gain, as well as reduction of feed conversion ratio. Blood analysis from the Sang groups and especially the Sang 50 group revealed low values of haptoglobin and serum amyloid A.

Future directions in the European union for veterinary education as related to food-producing animals, with special reference to Greece.

During the past 50 years, procedures for raising food-producing animals have changed. Intensification of food production was necessary to keep prices low and to fulfill market demands for the continuously increasing worldwide population. Intensification of farming procedures produced many new problems, some of which had a considerable impact on public opinion about how animals are raised and how food of animal origin is produced and preserved. "Man made diseases" of animals such as bovine spongiform encephalopathy (BSE); contamination of foods with dioxins either through contamination of animal feeds or from the environment; and increased microbial resistance to drugs used for treatment, for prophylaxis of animals from infectious agents, and for growth promotion are some well-known hazards of intensified farming. Veterinarians working on food-producing animals are faced with an increased demand for foods of high quality and safety in developed countries, and higher quantities in the rest of the world. These qualitative and quantitative changes indicate that they must adjust to these new conditions. They will be most successful if their education is adjusted to meet the challenges that the public has created for them through new concepts of the production of food of animal origin. One such concept is the production of foods under fully certified procedures from the farm to the consumer's table. Food safety measures protecting public health will better be achieved if the education of the future veterinarian includes the principles of Hazard Analysis Critical Control Points (HACCP) starting at farm level. This article provides some market-driven ideas in this direction for European Union (EU) countries, including Greece.