A study was conducted on 21 pig herds using one-site production system in the southeast region of Brazil to assess the relationships among serological results for primary pathogens involved in respiratory diseases (Actinobacillus pleuropneumoniae, App; Mycoplasma hyopneumoniae, Mhyo; and swine influenza virus, SIV), cough index, pneumonia index, pleuritis and herd characteristics. The prevalence of antibodies against Mhyo and SIV increased throughout the raising phases, with the highest prevalence in slaughtered pigs (> 40%), while pigs in 65% (14/21) of nurseries demonstrated marked seroprevalence of App that decreased until the day of slaughter. Pleuritis and pulmonary consolidations were recorded in 9.0 and 72.4%, respectively, of the 908 evaluated lungs. Histopathological analysis of the lung lesions revealed suppurative bronchopneumonia in almost half of the lungs (48.9%). Regression analyses were conducted to identify risk factors associated with the cough index; pleuritis; pulmonary consolidation; and App, Mhyo and SIV serological results. All-in-all-out management in nursery buildings reduced the seroprevalence of Mhyo in herds. App seroprevalence was associated with pleuritis, and the presence of cough episodes in growing pigs was associated with SIV seropositivity in nursery pigs.

Background The objective of the study was to evaluate the occurrence and severity of Porcine Respiratory Diseases Complex (PRDC) pathogens in the Goiás State, Brazil. Were assessed the serological antibodies occurrency of Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae and swine influenza virus (SIV), as well as the evaluation of pulmonary Mycoplasma-like lung lesions, pleuritis, histopathological lesions and diseases occurrence associated with risk factors, such as management, housing and productive indexes. We conveniently selected 2536 animals for serology testing, and 900 lungs at slaughtering of animals from 30 multisite herds in Goiás State, Brazil. Results For M. hyopneumoniae, all herds presented seropositive animals at some stage of production. Even though most herds (29/30) vaccinated against this pathogen, 90.0% (27/30) of the herds presented at least 50.0% of seropositive animals in finishing and slaughter. Overall, antibodies against A. pleuropneumoniae were present in lower occurrence, varying from 22.4% of the animals in the nursery phase to 1.3% of the animals at slaughter. Conversely, SIV circulated in most herds, with 29 seropositive herds without vaccination. The occurrence of anti-SIV antibodies was higher at slaughter (74.5% of the animals) than nursery (41.8% of the animals), and at slaughter, 23 herds (76.7%) presented at least 50.0% of seropositive animals. All herds presented animals with pulmonary Mycoplasma-like lung lesions, and of the 900 lungs evaluated in the slaughterhouse, 665 (73.9%) presented an average Mycoplasma-like lung lesions of 7.3%. Evaluations of the pneumonia index (PI) showed that 73.3% of the herds were strongly affected by a pathology that manifested itself in different presentation forms. Microscopically, there was a predominance of bronchopneumonia lesions (74.6% of affected lungs), with a high occurrence of the chronic form (57.1%), and there was a moderate to marked proliferation of bronchial associated lymphoid tissue (BALT) in 64.1% of the affected lungs. Pleuritis were observed in 13.5% of the animals. Conclusion Serological tests evidenced that antibodies against App and SIV were present in the Goiás State herds, and high occurrence of M. hyopneumoniae antibodies in finishing phases and slaughter may be influenced by pathogen circulation in vaccinated herds, leading to respiratory lesions at slaughter. Additionally, swine influenza virus was broadly disseminated in technified herds in Goiás State.

Mycoplasma suis and Mycoplasma parvum bind strongly to erythrocytes and may cause clinical hemoplasmosis in swine, affecting several age groups. Mycoplasma spp. infected animals may be asymptomatic carriers and/or show nonspecific clinical signs.In Brazil, information on genetic diversity associated with porcine hemoplasmas (PH) has not been described yet. Therefore, this study has aimed to detect, quantify and characterize the genetic diversity of PH in finishing pigs from technified farms in the state of Goiás, central-western Brazil. Ethylenediaminetetraacetic acid-blood samples from 450 swine belonging to 30 different farms from Goiás state were collected at the slaughterhouse. Quantitative real-time PCR (qPCR) assays were performed for the molecular detection and quantification of PH 16S rRNA gene fragments. Cloning and sequencing of 16S and 23S rRNA amplicons were performed to evaluate the genetic diversity. Moreover, a questionnaire was applied to each farm manager to obtain epidemiological information about the herd. The results on qPCR showed herd occurrence of 68.89% for PH. Quantification values (starting quantity [SQ]) ranged from 8.43 × 10 −1 to 4.69 × 10 6 copies/µl, and 52.71% of the samples presented SQ values equal or lower than 1 × 10 3 copies/µl. Risk factors were not evaluated once all farms had at least one positive animal. However, Spearman's coefficient test revealed that the occurrence of PH was inversely associated with the number of farrows per week, weaned piglets per week, and weight at slaughter. Phylogenetic analysis based on maximum likelihood and Bayesian methods showed that the 16S rRNA and 23S rRNA gene sequences obtained from five samples formed a single cluster closely related to M. parvum. Genotype analysis using DNASP software confirmed seven and four different 16S and 23S rRNA genotypes among the cloned amplicons, indicating that there are several genotypes of M. parvum circulating in individual pigs and among pig farms in central-western Brazil. K E Y W O R D S emerging disease, genotypes, intensive pig farming, Mycoplasma parvum, Mycoplasma suis, porcine hemoplasmas | 1163 SONALIO et AL. | INTRODUC TI ONHemotropic mycoplasmas (HMs) are known for infecting several mammal species, including wild and domestic pigs. Three hemoplasmas have been described in swine, namely Mycoplasma suis (Kinsley, 1932), Mycoplasma parvum (Splitter, 1950) and 'Candidatus M. haemosuis ' (Fu et al., 2017). The above-mentioned HMs induce red blood cells (RBCs) to undergo programmed cell death, also known as eryptosis, characterized by cell shrinkage, membrane blebbing, activation of proteases and phosphatidylserine exposure on the outer membrane leading to recognition by macrophages and, therefore, phagocytosis (Felder

RESUMO -O objetivo foi avaliar os efeitos da amamentação parcelada nas primeiras seis horas após o nascimento, sobre o peso ao desmame, aos 60 dias de idade e a dosagem de imunoglobulinas G séricas em leitões de porcas de diversas ordens de parto. Trinta e três fêmeas suínas foram usadas em delineamento inteiramente casualizado e em esquema fatorial 2 × 3, composto de dois manejos de leitões pós-nascimento e três agrupamentos por ordem de parto. No manejo tradicional, os leitões disputavam as tetas e mamavam aleatoriamente, enquanto no manejo com alimentação parcelada foram distribuídos em dois grupos para mamar. A coleta de sangue dos leitões foi realizada seis horas após o término do parto para titulação de IgG. Aos 21 e 60 dias de idade, os leitões foram pesados. O manejo de alimentação parcelada não afetou o peso nem a dosagem de IgG sérica dos leitões, independentemente da ordem de parição das porcas, no entanto os leitões das porcas primíparas apresentaram menor peso ao desmame. O manejo de alimentação parcelada resultou em aumento da concentração de IgG sérica dos leitões de porcas primíparas. A amamentação parcelada deve ser utilizada em primíparas, mas não necessariamente em porcas de segunda parição em diante, pois os leitões de primíparas submetidos ao manejo de alimentação parcelada apresentam maiores concentrações de IgG sérica.Palavras chave: IgG, imunidade passiva, manejo de leitões ao parto, suínos Split suckling in relation to the parturition order of sows ABSTRACT -The objective was evaluate the effects of the split suckling at the six first hours after the birth, on the weight at weaning and at 60 days of age and on the serum IgG rate, in piglets from sows of different parturition order. Thirtythree sows were used in a completely randomized design and 2 × 3 factorial arrangement: two post-birth management practices and three groups by parturition order. In the traditional management, piglets fought for the teats and suckled randomly, while in the split suckling, piglets were divided in two groups for suckling. Bood collection was performed at six hours after the end of the birth, for the IgG titration. At 21 and 60 days of age, piglets were weighed. The split suckling management did not affect the weight or the serum IgG rate of the piglets from sows of different parturition order, but the piglets of primiparous sows had lower weaning weight. The split suckling management resulted in increase of serum IgG concentration in piglets of primiparous sows. The split suckling must be used in primiparous sows, but not necessarily in sows of second parturition on, because the piglets of primiparous submitted to the split suckling management present higher concentrations of serum IgG. IntroduçãoOs leitões nascem sem proteção, mas adquirem imunidade passiva por meio da ingestão do colostro nas primeiras horas após o nascimento (Le Dividich et al., 2005;Svendsen et al., 2005). Leitões que não são amamentados por um período de até 60 minutos ou mais após o nascimento (Beynon, 2009) ou que não conseguem in...