V. S. Silva

Comparação entre métodos de tuberculinização no diagnóstico da infecção por agentes do complexo Mycobacterium avium ou M. bovis em suínos

The efficiency of the tuberculin delayed-type skin hypersensitivity test was evaluated in swine. A comparison of the tuberculin skin tests was performed with avian and bovine protein derivatives (PPD), in the detection of Mycobacterium avium-Complex or M. bovis infected swine. The methods were evaluated as to define criteria for readings and results interpretation, to determine their capacity in detecting Mycobacterium avium complex (MAC) infected swine and their performance in differentiating MAC from M. bovis-infected individuals. Three trials were performed with naturally MAC-infected swine, experimentally MAC-infected or experimentally M. bovis-infected animals. The skin test readings positive or negative were, respectively, correlated to the presence or absence of gross lesions and histological alterations in lymph nodes at slaughter age. Reaction with both antigens were observed in MAC and M. bovis-inoculated animals as well. Reactions wider then 0.5cm in diameter or showing skin thickness increasing more then 0.2cm in the time frame between inoculation and reading were considered to be positive, as compared to the average results of the group. Herds with MAC-infected swine could be detected with either avian or bovine PPD. Both diameter and skin thickness were efficient in detecting MAC-infected swine, however, reading the diameter of the reaction was shown to be more easily and economically performed.

Concentração de macronutrientes e metais pesados em maravalha de unidade de suínos em cama sobreposta

The swine production industry in Brazil has been severely criticized due to pollution, mainly in water, that has been noticed in regions where swine production is concentrated. This fact puts in question the current production model. Deep bedding system for swine production appears as a promising alternative, because it reduces the risks of contamination by converting manure management from liquid to solid phase. Additionally, it makes possible the production of organic compost, which can generate extra income or can be applied in the same farm to implement an organic agricultural production. This study evaluated the increase of macronutrients, copper and zinc concentrations in wood shavings used as a substrate in four stalls during a period when 8 groups of 70 animals were raised. Each stall had animals installed during 35 days, according to their age of entrance (nursery = 21, S1 = 56, S2 = 91 and S3 = 126 days). Results have shown that average concentrations of nutrients in beds are in compliance with legislation for simple organic fertilizer. The concentration of zinc in the nursery bed was about 5 times higher than other stalls, which shows the influence of diet on the composition of the compost.

Linfadenite granulomatosa em suínos: linfonodos afetados e diagnóstico patológico da infecção causada por agentes do Complexo Mycobacterium avium

A study to evaluate the distribution of granulomatous lesions in the lymph nodes of swine carcasses was accomplished. The main objective was to compare the methods of isolation of mycobacteria of the Mycobacterium avium Complex (MAC), Ziehl-Neelsen (ZN) staining, histopathological examination and immunohistochemistry (IHC) for the diagnosis of granulomatous lymphadenitis caused by MAC. A total of 431 samples of lymph nodes from 394 swine carcasses kept in 12 cold storage rooms of southern Brazil, which had the Service of Federal Inspection (SFI), were analyzed. Lymph nodes with granulomatous lesions were submitted to histological examination, ZN staining and IHC with monoclonal antibody produced with cellular extract of M. avium. The agreement between the exams was measured by the Kappa test at a 95% confidence level. The macrocospic examination done by SFI correctly identified 90.3% of granulomatous lesions, when compared with histological examination, and the majority of carcasses (92.5%) showed the lesions only in lymph nodes of the alimentary chain. Histological examination confirmed the presence of granulomatous lesions in 90.3% of the lymph nodes. The agreements between histological examination, ZN staining (Kappa: 0.342), IHC and the isolation of MAC (Kappa: 0.102) were low, however high between IHC and histology with typical presence of granulomas in the lymph nodes (Kappa: 0.973). IHC together with histological examination revealed to be efficient for identification of the granulomatous lymphadenitis caused by MAC.

Evaluation of litter material and ventilation systems in poultry production: I. overall performance

The objective of the present work was to evaluate the performance, mortality and the incidence of lesion on the foot-pad of broilers and litter enterobacteriaceae load in two ventilation systems and two litter materials. The experiment was carried out in four 12 m × 10 m broiler houses, internally divided in 4 pens, with 200 birds/pen for four consecutive flocks, each one with 42 days of duration and interval of 15 days of downtime between flocks. It was evaluated two ventilation systems (stationary and oscillating fans), and two litter materials (soybean straw and rice husks). Performance variables studied were body weight, weight gain, feed conversion ratio and mortality of birds at 21, 35, and 42 days of age. Flock mortality was daily recorded, and total mortality was used for analysis. Evaluation of lesions by using foot-pad macroscopic examination was performed in all birds at final weighing. It was also performed quantitative examinations of litter enterobacteria. Statistical analyses were performed by using the mixed model theory for repeated measures and logistical regression. Rice husks litter promoted the best performance of birds at all studied ages. Results did not permit to recommend a ventilation system inasmuch as both had similar performances. Soy straw litter causes a high incidence of foot-pad lesions. Enterobacteria occurrence is lower in reused litter.

Fatores de risco associados à ocorrência de linfadenite em suínos na fase de crescimento-terminação

An epidemiological study in 60 units of swine termination (UT), pertaining to producers integrated with the main Agribusiness of the States of Santa Catarina and Rio Grande do Sul. These units had been selected due to the occurrence of lymphadenitis in slaughtered pigs. The batch size studied in each UT varied from 22 to 960 pigs. The animals were considered positive or negative for lymphadenitis, following the evaluation routine of the Service of Federal Inspection (SIF) at slaughter. For data collection at the UTs, a questionnaire with 156 variables was applied at a single visit to the farms. In the 60 UT studied, the percentage of positive animals for lymphadenitis was 10.37%. Among the variables analyzed, nine risk factors were identified (explicative variables) and associated with the occurrence of lymphadenitis (objective variables). The explicative variables were: bad hygiene of the feeders and drinking fountains, untreated drinking water, bad conservation of the facilities, use of the same truck for ration and animal transportation, production of ration inside the farm, free access of other animals to the ingredients of ration, storage of ready usable ration in boxes or bags and handling of the production of animals in an continuous system.

Impact of treatments for recycled broiler litter on the viability and infectivity of microorganisms

The microbiological risk of recycled litter depends on the efficacy of the management system applied to inactivate residual microorganisms and preserve the health of the successive broiler flock. This study aimed to assess the viability and infectivity of the Newcastle Disease Virus (NDV), Infectious Bursal Disease Virus (IBDV) and Salmonella Heidelberg in recycled litter exposed to different treatments. The litter was contaminated with microorganisms and submitted to the treatments (T): T1: shallow fermentation; T2: quicklime (calcium oxide); T3: shallow fermentation followed by addition of quicklime; T4: no treatment. Sentinel chicks housed on the treated litter showed that T1 and T3 inactivated residual IBDV. Analysis of the litter subjected to T1 also showed reduced levels of total enterobacteria. T2 was not able to reduce the microorganisms assessed and its association with T1 (T3) failed to enhance the effect of the treatment. NDV did not survive in the broiler litter, regardless of the treatment applied, and it was also not detected in the sentinel chicks. S. Heidelberg remained viable in the litter submitted to all studied treatments, being isolated from the sentinel chicks of all the experimental groups. The antimicrobial activity of T1 and T3 was associated to higher ammonia contents in the broiler litter. The results indicate that the shallow fermentation treatment is efficient for controlling residual IBDV and total enterobacteria in the recycled litter.

Nem tudo que parece ser, é lesão: aspectos anatômicos, não lesões, artefatos, lesões sem significado clínico e alterações post mortem encontrados na necropsia de suínos domésticos e selvagens (Sus scrofa)

The interpretation of the changes observed at necropsy is an important step for the success of the final diagnosis. This article aims to describe and illustrate the anatomical structures, non-lesions, artifacts, lesions without clinical significance and postmortem changes observed in domestic and wild pigs. Moreover, the article also recommends collection techniques of organs or structures for the diagnosis of diseases affecting this species. The main anatomical structures and non-lesions described are marginal lingual papillae, pars oesophagea of the stomach, torus pyloricus, and well demarcated lobular pattern of the liver (gastrointestinal system); tonsils of the soft palate, gastric lymphoid tissue, Peyers patches of the small intestine, marginal folds of the spleen (hematopoietic system); prominent mediastinum testis and placental areolae (reproductive system); pulmonary atelectasis and periople (fetus); and carpal glands (integumentary system). The discussed artifacts related to euthanasia are petechiae on the surface of the lung and kidney, false anemia due to exsanguination, subdural hemorrhage due to cerebral concussion, pseudoinfarcts of the spleen, and cerebriform appearance of the small intestine. Lesions without clinical significance described are renal cysts, lymph nodes with iron pigment, papillomas and hemangiomas on the scrotum, osseous metaplasia in the mesentery, and hyperemia of the gastric mucosa. Commonly found postmortem changes are livor mortis, pale muscles, pseudomelanosis, and serosanguinous fluid in the thoracic and abdominal cavities of fetuses.