Genetic typing of porcine circovirus type 2 (PCV-2) isolates from Slovakia

Of 120 clinical specimens obtained from pigs bred on 28 PMWS-affected farms in Slovakia, porcine circovirus type 2 (PCV-2) was detected by single PCR in 77 samples. A short 224 bp fragment of ORF2 was used for preliminary grouping of isolates by phylogenetic analysis. Nucleotide sequences of the entire ORF2 region provided more precise genetic typing and segregation of preselected isolates (n = 10) into two known genotypes, PCV-2a (n = 1) and PCV-2b (n = 9). Complete genome sequencing of three selected isolates allowed their definitive grouping into genotype PCV-2b, cluster 1A or genotype PCV-2a, cluster 2D. No correlation between the mutations and the geographic origin of isolates was observed. Results confirmed that many PCV-2 isolates are genetically very stable since similar viruses circulate in Central and Western Europe.     

Effect of susceptibility to enterotoxigenic Escherichia coli F4 and of dietary tryptophan on gut microbiota diversity observed in healthy young pigs

Healthy weaned pigs susceptible to enterotoxigenic Escherichia coli F4 (ETEC) require more tryptophan (Trp) to maximize their performance. This may be related to an effect on intestinal microbiota. We studied the intestinal bacterial diversity of healthy pigs with different susceptibility to ETEC and fed different Trp levels. Thirty-six littermate weaned pigs were selected to obtain a set potentially formed of 50% ETEC-susceptible and 50% non-susceptible pigs, based on a Mucin 4 gene polymorphism. Pigs were fed a diet with 0.17 (TrpL) or 0.22 (TrpH) standardized ileal digestible Trp:Lys ratio for 21 days. Slaughtered pigs were classified into non-susceptible, mildly susceptible, and susceptible, by testing ETEC adhesion to intestinal villi. Bacterial diversity in jejunum content was assessed by the 16S rRNA gene-targeted denaturing gradient gel electrophoresis (DGGE) fingerprinting analysis and expressed by the Shannon index. Susceptible pigs had a reduced bacterial diversity, particularly with TrpL diet (p = 0.003). The ETEC adhesion class affected the quantification of enterobacteria DNA (p = 0.027). One DGGE band, which referred to Clostridium bartlettii, was not evidenced in all the susceptible pigs; less DNA from this microbe was quantified by RT-PCR in the jejunum from TrpH susceptible pigs (p = 0.025) compared to TrpL. The gene expression for β-galactoside α-2,3-sialyltransferase 1 was higher in jejunal tissue of ETEC-susceptible pigs (p = 0.019). In studies on pig gut microbiota, the presence of intestinal receptors for ETEC should be considered because of their contribution to a reduced bacterial diversity. This effect could be partially reversed by dietary Trp addition.     

Comparison of enzyme-linked immunosorbent assay and RT-PCR for the detection of porcine epidemic diarrhoea virus

Porcine epidemic diarrhoea (PED) is a contagious enteric disease of pigs caused by a coronavirus. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) based on the use of monoclonal antibodies was developed for the detection of porcine epidemic diarrhoea virus (PEDV). The DAS-ELISA was compared with RT-PCR in the examination of 506 specimens collected during 2006-2007 from pigs originating from different farms located in the Po valley. Both faecal samples obtained directly from the rectum of live animals showing clinical signs and intestinal samples collected from the caecum of deceased pigs were included in the study. The correlation between the two methods was higher when testing faecal samples (K = 0.97, 95% CI: 0.94-1.00) than testing intestinal samples (K = 0.62, 95% CI: 0.35-0.89). The use of ELISA technology provided an efficient and effective mean of evaluating the presence of coronavirus PED antigen in field samples and indicates that this procedure is a very useful tool in epidemiological studies.     

Evaluation on the pathogenicity of Erysipelothrix tonsillarum for pigs by immunosuppression with cyclophosphamide or dexamethasone

The pathogenicity of Erysipelothrix tonsillarum was evaluated in pigs immunosuppressed with cyclophosphamide (CY) or dexamethasone (DM). Animals were treated with 15 mg/kg CY (n = 8, five injections), 1 mg/kg DM (n = 8, nine injections) or left untreated (n = 8). On the fifth day after the beginning of drug treatments, swine were inoculated with one of two E. tonsillarum serovar 7 strains (approximately 10⁶ CFU per pig). In the CY-treated group, both circulating neutrophil and lymphocyte counts decreased, whereas in the DM-treated group, lymphocyte counts decreased but neutrophil counts increased. During the observation period, none of the CY- or DM-treated pigs developed clinical signs or gross lesions, as well as non-treated pigs. Growth agglutination antibody titres in all pigs remained unchanged. Our findings indicate that E. tonsillarum strains are avirulent for swine, regardless of immune status.     

Effect of piglet birth weight on body weight,growth, backfat,and longissimus muscle area of commercial market swine

The objective of this study was to estimate the effect of piglet birth weight on future BW, growth, backfat, and longissimus muscle area of pigs in a commercial U.S. production system. Pigs (n = 5727) at a commercial farm were individually weighed and identified within 24 h of birth. Weights were collected prior to weaning (n = 4108), after finisher placement (n = 3439), and 7 (n = 1622) and 16 (n = 1586) weeks into finishing; hot carcass weight was also collected (n = 1693). Average daily gain during lactation, nursery, finishing, and overall (birth to 16 weeks into finishing) was calculated. During BW collection 16 weeks into finishing, real-time ultrasound backfat thickness and longissimus muscle area were measured. Sex × birth weight (linear and quadratic) interactions were observed for BW at weaning and finisher placement and daily gain during pre-weaning and nursery. Linear birth weight × cross foster interactions were observed for weaning weight and pre-weaning gain. Linear and quadratic effects of birth weight on BW at weaning, finisher placement, 7 and 16 weeks into finishing, and hot carcass weight and average daily gain during pre-weaning, nursery, finishing, and total were observed. For all measures of BW and average daily gain, as birth weight increased subsequent BW and average daily gain increased at a decreasing rate; however, for the sex × birth weight (linear and quadratic) interactions, heavier birth weight barrows were lighter and grew slower than gilts of comparable birth weight. Worth noting, the birth weight × sex interactions described very few pigs in the extreme portion of the birth weight distribution. For birth weight × cross foster interactions, non-cross fostered pigs were increasingly heavier and faster growing as birth weight increased compared to cross fostered pigs. Heavier birth weight pigs tended to have increased backfat depth (P = 0.07). Linear and quadratic effects of birth weight on longissimus muscle area were observed; as birth weight increased muscling increased at a decreasing rate. Regardless of interactions or period of production, increased birth weight resulted in heavier future BW, faster daily gain along with larger longissimus muscle area prior to harvest. In all instances the magnitude of the negative effect of birth weight increased as birth weight decreased.     

Molecular epidemiology of Mycobacterium avium subspecies paratuberculosis: IS900 PCR identification and IS1311 polymorphism analysis from ruminants in the Punjab region of India

Johne's disease is chronic granulomatous infectious enteritis of animals caused by Mycobacterium avium subspecies paratuberculosis. A total of 153 animals from 19 dairy farms, 2 gaushalas (unproductive-animal rehabilitation centers), 2 goat and 2 sheep farms from different districts of the Punjab region were selected on the basis of clinical signs of disease. All samples from cattle (n = 86), buffalo (n = 34), goat (n = 25) and sheep (n = 26) were subjected to Ziehl-Neelsen staining and DNA extraction by a freeze and thaw method. Ziehl-Neelsen staining detected 71% samples positive for acid-fast bacilli whereas IS900 PCR detected 55% positive for Map DNA. IS1311 PCR-REA analysis of IS900 positive samples revealed ‘Bison’ type as the most prevalent (82%) genotype of Map, infecting all domestic ruminants. ‘Cattle’ type was present in a minority of cases (15%) from cattle, buffaloes and goats. This is the first report of ‘Cattle’ type Map from buffalo and goat species in India.     

Inflammation-associated responses in piglets induced with post-weaning colibacillosis are influenced by dietary protein level

Forty piglets (average body weight = 5.32 kg) were used to investigate the effect of dietary crude protein (CP) content on immunological responses following a challenge with enterotoxigenic Escherichia coli (ETEC) K88. Pigs, housed 4 per pen, were randomly allotted to 2 diets: 1) a high, 225 g/kg CP diet (HCP) or 2) a low, 176 g/kg CP diet (LCP) supplemented with crystalline amino acids. Pigs were orally challenged with 6 mL of an ETEC K88 suspension containing 10¹⁰ cfu/mL on d 8 after weaning. Blood samples were collected from 10 pigs (1 pig/pen) on d 7 (at weaning), −24 h, 8 h, 72 h and 7 d after the challenge for determination of plasma urea N (PUN) and serum concentrations of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) and haptoglobin (Hp). Tumor necrosis factor alpha, IL-1β and Hp were measured as indicators of inflammatory responses. The concentrations of serum TNF-α at 8 h, 72 h and 7 d after challenge were similar to the level observed at 24 h before challenge but higher (P < 0.05) than the weaning level. Pigs fed the LCP diet had lower (P = 0.032) concentrations of IL-1β (72 vs. 116 pg/mL) at 8 h post-challenge compared with those fed the HCP diet. Likewise, pigs fed the LCP diet tended to have lower (P = 0.088) concentration of Hp (9 vs. 25 mg/dL) compared with those fed the HCP diet at 8 h post-challenge. Compared with the weaning concentration, PUN concentration at 72 h after ETEC challenge was higher (P < 0.05) in pigs fed the HCP diet. The results indicate that the LCP diet supplemented with crystalline amino acids reduced inflammatory responses, as indicated by serum IL-1β, in piglets infected with ETEC K88.     

Pathogenesis of GIII.2 bovine norovirus,CV186-OH/00/US strain in gnotobiotic calves

The pathogenesis of GIII.2 bovine norovirus (BoNoV) is not well understood. Our study demonstrated persisting diarrhea and prolonged fecal shedding, but with a lack of significant intestinal lesions in gnotobiotic (Gn) calves infected with GIII.2 BoNoV, CV186-OH/00/US strain. Nine 4 to 7-day-old Angus/Jersey crossbred Gn calves were orally inoculated with 10.0–11.9 log₁₀ genomic equivalents (GE)/calf of CV186-OH (n = 7) or mock (n = 2). Calves were euthanized at post-inoculation day (PID) 1 (n = 1) when moderate to severe lethargy was observed and at PIDs 2–6 (n = 4) after lethargy had subsided. Two calves were kept longer term (until PID 30) for monitoring fecal shedding patterns by TaqMan real-time RT-PCR (qRT-PCR). Most infected calves exhibited two clinical signs: (i) acute but persisting diarrhea and (ii) acute moderate to severe lethargy. The two infected calves, followed longer-term, had prolonged fecal viral RNA shedding [peak average titer of 11.8 (±0.2) log₁₀ GE/ml] at least until PID 20. By qRT-PCR, 5 infected calves had low viral RNA titers in serum, ranging from 4.0 to 5.8 log₁₀ GE/ml, at PIDs 1–5, but not (<2.7 log₁₀ GE/ml) at PIDs 6–30. The latter observation coincided with the presence of serum IgG antibody to BoNoV at PIDs 8–30. Collectively, the GIII.2 BoNoV strain CV186-OH induced only mild enteropathogenicity, evident by the lack of significant intestinal lesions, but it led to persisting mild diarrhea and prolonged fecal virus shedding in Gn calves. The prolonged fecal shedding of GIII.2 BoNoV might partially explain how this virus is maintained as endemic infections in cattle.     

Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt

Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n = 1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n = 1242) and wild birds (n = 807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n = 306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p < 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F = 29.5, p < 0.0001).     

Bartonella and Babesia infections in cattle and their ticks in Taiwan

Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n = 254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25 (42.4%) beef cattle and 40 (15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n = 10, 1.9%) or B. bigemina (n = 3, 0.6%).     

Efficacy of a single high oxfendazole dose against gastrointestinal nematodes in naturally infected pigs

The goal of the current experiment was to assess the clinical efficacy of oxfendazole (OFZ) administered as a single oral dose (30 mg/kg) to pigs naturally parasitized with Ascaris suum, Oesophagostomum spp., Metastrongylus spp. and Trichuris suis. Thirty-six local ecotype piglets were divided into three independent experiments, named I, II and III (n = 12 each), respectively. Each experiment involved two different groups (n = 6): Untreated Control and OFZ treated. Animals were naturally parasitized with A. suum (Experiments I, II and III), Oesophagostomum spp. (Experiments I and II), T. suis (Experiments II and III) and Metastrongylus spp. (Experiment I). Pigs in the treated group received OFZ (Synanthic^®, Merial Ltd., 9.06% suspension) orally at 30 mg/kg dose. At five (5) days post-treatment, animals were sacrificed and the clinical efficacy of the OFZ treatment was established following the currently available WAAVP guidelines for a controlled efficacy test. None of the animals involved in this experiment showed any adverse events during the study. OFZ treatment given as a single 30 mg/kg oral dose showed a 100% efficacy against all the nematode parasites present in the three experiments. In conclusion, under the current experimental conditions, OFZ orally administered to naturally parasitized piglets at a single dose of 30 mg/kg was safe and highly efficacious (100%) against adult stages of A. suum, Oesophagostomum spp., T. suis and Metastrongylus spp.     

Porcine circovirus type 2 (PCV2) vaccination reduces PCV2 in a PCV2 and Salmonella enterica serovar Choleraesuis coinfection model

We previously reported that prior porcine circovirus type 2 (PCV2) infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of Salmonella enterica serovar Choleraesuis in infected pigs. Here, we evaluated whether PCV2 vaccination is effective in reducing fecal shedding and tissue dissemination of S. Choleraesuis and improving clinical signs associated with PCV2 and S. Choleraesuis infection in 15 Cesarean-derived, colostrum-deprived pigs randomly assigned to 3 groups (n = 5/group). The vaccinated and co-infected (VAC-COINF) group received 2 ml of a commercial PCV2 vaccine at age 3 weeks. The VAC-COINF and co-infected (COINF) groups were inoculated intranasally with PCV2 and S. Choleraesuis at 5 and 7 weeks of age, respectively. The CONTROL group pigs received a similar volume of PBS for sham-vaccination and sham-inoculation. PCV2 vaccination clearly reduced PCV2 DNA load in the serum and postmortem tissue samples and decreased PCV2 antigen levels in tissue samples of the VAC-COINF group. After S. Choleraesuis infection, the incidence of several clinical signs increased in the VAC-COINF group compared to that in the COINF group. The microscopic lung lesions and weight gain, fecal shedding and tissue dissemination of S. Choleraesuis except in the spleen were not significantly different in the VAC-COINF and COINF groups. Thus, PCV2 vaccination reduced PCV2 in the S. Choleraesuis and PCV2 coinfection model and the effects on S. Choleraesuis were minimal.     

Effects of dibutyryl cAMP on growth performance and carcass traits in finishing pigs

This study was designed to investigate the effects of dietary supplementation with N⁶, 2′-O-dibutyryl adenosine 3′,5′-cyclic monophosphate (dbcAMP) on growth performance, carcass traits, histochemical characteristics and serum constituents in finishing pigs. Seventy-two Duroc × (Landrace × Large White) barrows (57.3 ± 0.6 kg) were randomly allotted to 3 treatments with 6 replicate pens/treatment (4 pigs/pen). The pigs were fed diets containing 0, 10 and 20 mg dbcAMP/kg, respectively, until the final slaughter weight of approximately 90 kg. There were no differences in growth performance among dietary treatments. Leaf fat proportion and first rib backfat thickness were reduced (P < 0.05), whereas tenth rib backfat thickness tended to decrease (P = 0.10), in pigs fed 10 mg dbcAMP/kg. Lean percentage was greater (P < 0.05) and longissimus muscle area tended to increase (P = 0.10) in pigs fed 10 mg dbcAMP/kg when compared to the control group, but hot carcass weight was not affected by dbcAMP. Growth rate of fat-free lean tissues tended to increase (P = 0.09) in dbcAMP-supplemented pigs. Dietary dbcAMP decreased (P < 0.05) adipocytes diameter in subcutaneous fat, whereas longissimus muscle fiber diameter tended to increase (P = 0.06) with dbcAMP supplementation; however, no difference in longissimus muscle cell density was detected among treatments. Serum concentrations of total protein and 3′,5′-cyclic adenosine monophosphate increased (P < 0.05) in response to dbcAMP, but concentrations of triglycerides, total cholesterol, glucose and urea in serum did not differ among dietary treatments. These results indicate that dbcAMP had a positive effect on carcass traits. Addition of 10 mg dbcAMP/kg to the diet was beneficial for growth performance and lean percentage, as well as improving protein and fat metabolism.     

Evidence for widespread Leishmania infantum infection among wild carnivores in L. infantum periendemic northern Spain

Leishmania spp. infection was investigated in tissue samples of wild carnivores from the Spanish Basque Country (BC), by PCR and DNA sequencing. The region is at the northern periphery of Leishmania infantum endemic Iberian Peninsula and infection in the dog (reservoir) or other species has not been previously reported. Leishmania kinetoplast DNA was detected by real-time PCR (rtPCR) in 28% (44/156) of animals. Specifically, in 26% of Eurasian badgers (n = 53), 29% of foxes (n = 48), 29% of stone martens (n = 21) and in 25–50% of less numerous species including genets, wild cats, pole cats, European mink and weasels. Infected animals particularly badgers, were most prevalent in the southernmost province of the BC (Araba) in areas dominated by arable land. Subsequent amplification and sequencing of a fragment of the rRNA internal transcribed spacer 2 (ITS2) from a subset of rtPCR positives samples confirmed the species as L. infantum, showing a high sequence homogeneity with ITS2 sequences of L. infantum from dogs and humans from southern Spain. In summary, this study reports for the first time L. infantum infection in wild carnivores from the BC including in stone martens, pole cats and minks in which infection has not been previously described. It supports the need to study infection in dogs and people in this region and is an example of the value of infection surveillance in wildlife to assess potential risks in the domestic environment and their role in spreading infections in non-endemic areas.     

Evaluation of serum galactomannan detection for diagnosis of feline upper respiratory tract aspergillosis

Measurement of serum galactomannan (GM), a polysaccharide fungal cell-wall component, is a non-invasive test for early diagnosis of invasive aspergillosis in humans. Feline upper respiratory tract (URT) aspergillosis is an emerging infectious disease in cats. Diagnosis requires biopsy for procurement of tissue specimens for cytological or histological detection of fungal hyphae and for fungal culture. The aim of this study was to evaluate serum GM measurement as a non-invasive diagnostic test for URT aspergillosis in cats. A one-stage, immunoenzymatic sandwich ELISA was used to detect serum GM in 4 groups of cats; Group 1 (URT aspergillosis) – confirmed URT aspergillosis (n = 13, sinonasal aspergillosis (SNA) n = 6 and sino-orbital aspergillosis (SOA) n = 7), Group 2 (URT other) – other URT diseases (n = 15), Group 3 (β-lactam) – cats treated with β-lactam antibiotics for non-respiratory tract disease (n = 14), Group 4a – healthy young cats (≤1 y of age, n = 28), Group 4b – healthy adult cats (>1 y of age, n = 16). One cat with SNA and two cats with SOA caused by an Aspergillus fumigatus-mimetic species, tested positive for serum GM. For a cut-off optical density index of 1.5, the overall sensitivity and specificity of the assay was 23% and 78% respectively. False positive results occurred in 29% of cats in Group 3 and 32% of cats in Group 4a. Specificity increased to 90% when Groups 3 and 4a were excluded from the analysis. Overall, serum GM measurement has a poor sensitivity but is a moderately specific, non-invasive screening test to rule out infection in patients with suspected feline upper respiratory tract aspergillosis.     

Antibiotic resistances of intestinal lactobacilli isolated from wild boars

Acquired antibiotic resistances have been reported in lactobacilli of various animal and food sources, but there are no data from wild boar. The objective was a preliminary examination of the antibiotic resistance prevalence of intrinsically vancomycin-resistant lactobacilli isolated from wild boar intestines and analysis of the genetic determinants implicated. Out of three wild boars, 121 lactobacilli were recovered and grouped according to their whole cell protein patterns. Initial phenotypic screening revealed that all were susceptible to erythromycin (2 μg/ml), but 30 were resistant to tetracycline (32 μg/ml). Based on Randomly Amplified Polymorphic DNA-PCR clustering, 64 strains were selected as representative genotypes for identification and minimum inhibitory concentration (MIC) determination. Partial 16S rRNA gene sequencing identified four species: (i) L. mucosae (n = 57), (ii) L. reuteri (n = 47), (iii) L. fermentum (n = 12), and (iv) L. murinus (n = 5). Most heterofermentative strains displayed low MICs for ampicillin (AMP), chloramphenicol (CHL), streptomycin (STR), kanamycin (KAN), gentamicin (GEN), erythromycin (ERY), quinupristin/dalfopristin (Q/D), and clindamycin (CLI). Atypical MICs were found mainly in L. mucosae and L. reuteri for TET, KAN, STR, AMP and CHL, but except the TET MICs of L. mucosae mostly at low level. L. murinus strains revealed atypical MICs for aminoglycosides, and/or CHL, AMP, CLI. PCR screening detected tet(W) in 12 and tet(M) in one of heterofermentative strains, as well as the aph(3′)-III kanamycin gene in L. murinus. This is the first report showing acquired antibiotic resistance determinants in intestinal lactobacilli of wild boar origin.     

Evaluation of the immune response induced by intradermal vaccination by using a needle-less system in comparison with the intramuscular route in conventional pigs

The immune response induced by intradermal vaccination using a needle-less device was evaluated in conventional pigs in comparison with the more conventional intramuscular vaccination; to this purpose, vaccination against Aujeszky’s Disease (AD) was used as a model of antiviral immunity. Two groups of pigs (n = 10 each) were vaccinated 4 weeks apart respectively by the intramuscular (IM group) and intradermal route (ID group; needle-less I.D.A.L.® vaccinator) with an AD modified live virus. Ten pigs injected with the vaccine adjuvant only were kept as sham-vaccinated controls (C group).On blood samples collected at 0, 2, 4, 5, 6 and 7 weeks post-vaccination (PV) ADV-specific virus neutralizing (VN) antibodies, IFN-γ secreting cells (SC), lymphocyte subsets and IFN-γ gene expression in PBMC were evaluated.VN antibodies increased after the 1st vaccination and peaked after the 2nd vaccination in both vaccinated groups. Also IFN-γ SC reached maximum levels in both groups after administration of the booster dose. Pigs in the control group remained negative for both parameters throughout the study. Flow cytometry showed persistently higher levels of CD3−CD8α+ Natural Killer cells in both vaccinated pigs. The ID group showed an earlier and regulated activation characterized by an increase of cytotoxic CD8β+ T lymphocytes and CD25+ cells after the boosting dose. No statistically significant differences between treated and control groups were detected for memory CD4+CD8α+^low T cells. Upregulation of IFN-γ gene expression in PBMC was detected in ID and IM pigs after both vaccine administrations, although at a different extent. Overall, the results showed that the intradermal vaccine delivery by a needle-less device can prime a strong humoral and cellular immune response comparable to that obtained by the intramuscular vaccination.     

Canine babesiosis caused by Babesia canis vogeli in rural areas of the State of Minas Gerais, Brazil and factors associated with its seroprevalence

This epidemiological survey on canine babesiosis was carried out in three distinct rural regions (Lavras, Belo Horizonte and Nanuque) of the State of Minas Gerais, Brazil. Ticks and blood samples were collected during a dry season (Lavras, n = 92; Belo Horizonte, n = 50; Nanuque, n = 102) and the subsequent rainy season (Lavras, n = 71; Belo Horizonte, n = 28; Nanuque, n = 66) from dogs living on farms. Plasma samples were analyzed by the indirect fluorescent antibody test for detection of anti-Babesia canis vogeli antibodies. DNA was extracted from blood of serologically positive dogs and molecular characterization of Babesia species was performed. Rhipicephalus sanguineus, Amblyomma cajennense and Boophilus microplus were the tick species identified in all regions. In Lavras, in addition to those tick species, A. tigrinum and A. ovale were also identified. The most prevalent tick species was A. cajennense (35.3%), followed by R. sanguineus (19%) and B. microplus (4.0%). Dogs living in Nanuque region were more heavily infested with ticks than dogs living in Belo Horizonte and Lavras regions. The overall frequency of anti-B. c. vogeli antibodies in the canine population in rural areas of Minas Gerais was 28.7%, with prevalence rates of 49.0% in Nanuque, 34.0% in Belo Horizonte and 3.3% in Lavras. The age of the animals and tick infestation were associated with seroprevalence of B. c. vogeli. The sequence analysis showed that B. c. vogeli was the only Babesia species present in all three regions. This study showed different rates of prevalence and incidence of canine babesiosis among the three rural regions sampled in Minas Gerais State. The results point to the importance of canine babesiosis in rural areas and to the need for further studies related to its transmission and maintenance in nature.     

Intra-uterine insemination with low numbers of frozen–thawed boar spermatozoa in spontaneous and induced ovulating sows under field conditions

The present study was conducted to evaluate non-return rate (NR), farrowing rate (FR), and number of total pigs born/litter (TB) of weaned sows after intra-uterine insemination (IUI) using low numbers of frozen–thawed (FT) spermatozoa. Semen from 6 boars was cryopreserved individually in a 0.5-ml straw, at a concentration of 1 × 10⁹ spermatozoa/ml. A total of 40 multiparous sows with weaning-to-estrus interval of 3 to 7 days were included. The sows were detected for standing estrus twice daily and randomly assigned to two groups: I) spontaneous ovulation (n = 20) and II) induced ovulation (n = 20) which the sows were given 750 IU human chorionic gonadotrophin (hCG) i.m. immediately at estrus detection. Ovulation was determined every 12 h using transrectal ultrasonography. FT semen containing 1 × 10⁹ motile spermatozoa/dose was used to IUI. In group I, the sows were inseminated at 24 h after the detection of estrus and repeated every 12 h until ovulation. In group II, the sows were inseminated at 36, 42 and/or 48 h after hCG treatment. The results showed that the interval from standing estrus to ovulation (EOI) differed significantly between group I (40.2 h) and group II (35.6 h; P = 0.01). Variation of EOI among sows within each group seemed to be lower in group II (4.5 h SD) than in group I (5.5 h SD; P = 0.5). The number of IUI per sow was 2.9 ± 0.6 times in group I and was 2.4 ± 0.5 times in group II. There were no significant differences (P > 0.05) in the NR (80 vs 85%), FR (60 vs 65%) and the TB (8.0 ± 2.8 vs 9.4 ± 3.7 piglets/litter) between the groups. These results indicated that multiple doses of IUI with a low number of FT boar spermatozoa provided a fairly good NR, and reasonable FR and TB both in spontaneous and induced ovulating sows. The number of inseminations required for attaining acceptable fertility tended to be lower in the weaned sows with induced ovulation.