Technological level and epidemiological aspects of sheep husbandry in Minas Gerais, southeastern Brazil / Nível tecnológico e aspectos epidemiológicos da ovinocultura no estado de Minas Gerais, Sudeste do Brasil

Epidemiological and health aspects of sheep husbandry were assessed on 213 sheep flocks in 142 municipalities from the state of Minas Gerais, southeastern Brazil. An updated questionnaire was filled out for each flock, requesting data on the farm, the flock and the farmer by the veterinarians of the State Government Agency for Animal Health (Instituto Mineiro de Agropecuária). Thirteen important variables were selected and scored to determine the technological level of the 117 farms; 0.9% of them was classified as high technological level, 45.3% as medium technological level and 53.0% as low technological level. Lamb production was the main objective of the farms and the main features were low-frequencies of individual identification of animals (16.9%), technical assistance (31.9%), use of quarantine for newly acquired animals (0.9%) the separation of animals by age group (3.7%) and requeste the sanitary certificate at purchasing of animals (11.7%). The main health problems reported were abortion (23.9%), keratoconjunctivitis (17.9%), contagious ecthyma (13.6%), pneumonia (10.3%), diarrhea (9.3%) and caseous lymphadenitis (6.1%). Information of the epidemiological situation and the mainly health measures used in the sheep farms are important to improve the productivity and quality of the lamb...

Os aspectos epidemiológicos e sanitários da ovinocultura foram levantados em 213 rebanhos ovinos em 142 municípios do estado de Minas Gerais, sudeste do Brasil. Um questionário atualizado foi preenchido para cada rebanho, com informações sobre a fazenda, o rebanho e do fazendeiro, por veterinários do Instituto Mineiro de Agropecuária. Treze variáveis importantes foram selecionadas e pontuadas para determinar o nível tecnológico em 117 fazendas; 0,9% foram classificadas como de alto nível tecnológico, 45,3% como de médio nível tecnológico e 53,0% como de baixo nível tecnológico. A produção de carne de cordeiro foi o principal objetivo das fazendas amostradas e as principais características foram baixa frequência de identificação individual dos animais (16,9%), assistência técnica (31,9%), uso de quarentena para os animais recém-adquiridos (0,9%), separação de animais por faixa etária (3.7%) e solicitação de certificados sanitários na compra de animais (11,7%). Os principais problemas sanitários relatados foram o aborto (23,9%), ceratoconjuntivite (17,9%), ectima contagioso (13,6%), pneumonia (10,3%), diarreia (9,3%) e linfadenite caseosa (6,1%). Informações sobre a situação epidemiológica e das principais medidas sanitárias utilizadas nas propriedades com ovinos são importantes para melhorar produtividade e a qualidade da carne ovina...

Evaluation of ERIC-PCR as genotyping method for Corynebacterium pseudotuberculosis isolates.

The aim of this study was to evaluate the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis isolates from eight different hosts in twelve countries. Ninety-nine C. pseudotuberculosis field strains, one type strain (ATCC 19410T) and one vaccine strain (1002) were fingerprinted using the ERIC-1R and ERIC-2 primers, and the ERIC-1R+ERIC-2 primer pair. Twenty-nine different genotypes were generated by ERIC 1-PCR, 28 by ERIC 2-PCR and 35 by ERIC 1+2-PCR. The discriminatory index calculated for ERIC 1, ERIC 2, and ERIC 1+2-PCR was 0.89, 0.86, and 0.92, respectively. Epidemiological concordance was established for all ERIC-PCR assays. ERIC 1+2-PCR was defined as the best method based on suitability of the amplification patterns and discriminatory index. Minimal spanning tree for ERIC 1+2-PCR revealed three major clonal complexes and clustering around nitrate-positive (biovar Equi) and nitrate-negative (biovar Ovis) strains. Therefore, ERIC 1+2-PCR proved to be the best technique evaluated in this study for genotyping C. pseudotuberculosis strains, due to its usefulness for molecular epidemiology investigations.

Validation of a microsatellite panel for parentage testing of locally adapted and commercial goats in Brazil.

Brazilian goats are generally kept in small herds and extensive rearing systems, mainly in the northeastern region of the country. Despite production improvement in recent years, the lack of pedigree control has affected genetic progress. This study aimed to validate a panel of 16 microsatellites for parentage testing in locally adapted and commercial goats breeds raised in Brazil, as well as to compare its efficiency with the panel recommended by the Brazilian Ministry of Agriculture, Livestock and Supplies (MAPA) in 2004. The number of alleles and expected heterozygosity (He) per marker ranged from four to 18, and from 0.051 to 0.831, respectively. Using all markers, 100% of parentage cases of the validation dataset were resolved with a strict confidence level of 95%. The 16 microsatellites panel showed adequate exclusion power (99.99%) and identity accuracy (99.99%). Suggestions for improvement of the marker panel endorsed by MAPA are provided.

Distribution of caprine arthritis encephalitis virus provirus, RNA, and antigen in the reproductive tract of one naturally and seven experimentally infected bucks.

Caprine arthritis encephalitis is a worldwide, multisystemic disease caused by a small ruminant lentivirus. Although the main route of transmission is oral, detection of proviral DNA of the caprine arthritis encephalitis virus (CAEV) in caprine semen has been previously described. However, the presence of viral antigens in the male reproductive tract has apparently never been reported. The objective was to study lesions in the buck reproductive system and to detect, in these tissues, the presence of proviral DNA, viral RNA and CAEV antigens. Tissues from eight CAEV-infected bucks (one naturally and seven experimentally infected) were analyzed by histopathology, nested polymerase chain reaction, reverse transcriptase-polymerase chain reaction, and immunohistochemistry. Interstitial pneumonia, synovitis, and lesions in the male reproductive tract were detected in some of the bucks. Proviral DNA was detected in the lungs and joints as well as in the reproductive systems of all animals, whereas viral RNA was detected only in the genital tract of the naturally infected buck. Viral antigens were immunostained in most of the organs of the male reproductive tract. This report was apparently the first to clearly demonstrate CAEV antigen expression in the male reproductive tract, which indicates the possibility of venereal transmission of CAEV.

Management practices to control gastrointestinal parasites in sheep farms in Minas Gerais, southeastern Brazil / Práticas de manejo para controle de parasitas gastrointestinais em fazendas com ovinos em Minas Gerais, Sudeste do Brasil

Parasite related problems are considered one of the major health problems for sheep breeding, causing considerable economic losses to commercial husbandry. The aim of this study was to determine the technological level and the level of knowledge of farmers regarding management practices to control gastrointestinal parasites in sheep in Minas Gerais state, southeastern Brazil. The analysis was based on 213 questionnaires applied by official veterinarians of the State Government Agency for Animal Health (Instituto Mineiro de Agropecuária, IMA), covering 16.6% of all counties. From two hundred and thirteen sheep farms sampled, 117 farms had their technological level determined. From the samples, 0.9% were characterized as high level, 45.3% as medium, and 53.0% as low technological level. The flock size ranged from 2 to 1843 with an average of 80.5 sheep per farm. The majority of the sheep production systems was extensive/semi-extensive (74.5%). The management practices adopted by the farmers to reduce parasitism were: split young and adult animals (5.6%), change pasture after deworm the animals (5.2%), use quarantine for incoming animals (2.3%), deworm newly arrived sheep (1.5%), and have regular technical assistance (31.9%). Although 76.5% of the farmers medicate the animals, treatments were performed without any major technical criteria, with an average interval of 4.6 months. The most commonly used drug families were macrocyclic lactones (38.5%) and benzimidazoles (24.9%). The management practices adopted in Minas Gerais are based on old recommendations and may not return in a good set of strategies to prevent parasite infections. Field observations reinforce the finding where farmers have obtained unsatisfactory results in maintaining the health and productivity level of their enterprises.

Problemas relacionados com parasitas são considerados um dos principais problemas sanitários na criação de ovinos, causando consideráveis perdas econômicas para criação comercial. O objetivo deste estudo foi determinar o nível tecnológico e o nível de conhecimento dos criadores sobre práticas de manejo para o controle de parasitas gastrintestinais em ovinos no estado de Minas Gerais, sudeste do Brasil. A análise foi baseada em 213 questionários aplicados pelos veterinários oficiais da Agência de Governo Estudal de Saúde Animal (Instituto Mineiro de Agropecuária, IMA), cobrindo 16,6% de todos os municípios. Duzentos e treze propriedades com ovinos foram amostradas e 117 tiveram o seu nível tecnológico determinado. A partir da amostra, 0,9% foi caracterizado como nível elevado, de 45,3%, como de médio e 53,0% como baixo nível tecnológico. O tamanho do rebanho variou de 2 a 1843 com uma média de 80,5 ovinos por propriedade. A maioria dos sistemas de produção de ovinos eram extensivos/semi-extensivos (74,5%). As práticas de manejo adotadas pelos criadores para reduzir o parasitismo foram: separar animais jovens e adultos (5,6%), mudança de pastagem após vermifugar os animais (5,2%), uso de quarentena para animais recem adiquiridos (2,3%), vermifugação de ovelhas recém-chegadas (1,5%) e assistência técnica regular (31,9%). Apesar de 76,5% dos criadores vermifugarem os animais, os tratamentos foram realizados sem qualquer critério técnico importante, com um intervalo médio de 4,6 meses. As famílias de drogas mais comumente usadas foram lactonas macrocíclicas (38,5%) e benzimidazóis (24,9%). As práticas de manejo adotadas em Minas Gerais são baseadas em recomendações antigas e não em estratégias para prevenir infecções parasitárias. As observações de campo reforçam os achados em que os proprietários obtiveram resultados insatisfatórios na manutenção dos níveis de saúde e produtividade de seus empreendimentos.

High sero-prevalence of caseous lymphadenitis identified in slaughterhouse samples as a consequence of deficiencies in sheep farm management in the state of Minas Gerais, Brazil.

BACKGROUND: Caseous lymphadenitis (CLA), caused by Corynebacterium pseudotuberculosis, is one of the most important diseases of sheep and goats, causing considerable economic losses for herd owners. RESULTS: We assessed the seroprevalence of infection with C. pseudotuberculosis in 805 sheep from 23 sheep farms that supply slaughterhouses in the state of Minas Gerais; we also analyzed management practices that could be associated with CLA occurrence, used on these and nearby farms that also supplied animals to the slaughterhouse (n = 60). The serum samples for assaying CLA infection were taken at the slaughterhouse. Frequency of infection with C. pseudotuberculosis was estimated at 43.7%, and farm frequency was estimated at 100%. Management practices were analyzed through a questionnaire. All farmers (60/60) had extensive/semi-extensive rearing system; 70.0% (42/60) identified sheep individually; 11.7% (7/60) had periodical technical assistance; 41.7% (25/60) disinfected the facilities; 86.7% (52/60) used barbed wire fences and did not implement adequate CLA control measures; only 11.7% (7/60) of breeders reported vaccination against C. pseudotuberculosis; 13.3% (8/60) took note of animals with clinical signs of CLA; 1.7% (1/60) opened and sanitized abscesses, and isolated the infected animals; 10.0% (6/60) knew the zoonotic potential of this disease and 1.7% (1/60) of the farmers culled animals in case of recurrence of abscesses. CONCLUSIONS: It can be concluded that C. pseudotuberculosis infection is widely spread in sheep flocks in Minas Gerais state in Brazil and that there is a lack of good management measures and vaccination, allowing transmission of this infectious agent throughout the production network.

Development and evaluation of a species-specific PCR assay for the detection of Brucella ovis infection in rams.

Brucella ovis infection is a major cause of epididymitis and infertility in rams, resulting in reproductive failure and significant economic losses worldwide. The goal of this study was to develop a PCR test targeting specific B. ovis genomic sequences. Specific primer pairs were designed targeting 12 of those ORFs. Samples of blood, serum, semen, urine, and preputial wash were collected from experimentally infected rams (n=9) every other week up to 180 days post infection (dpi), when tissue samples were obtained. Blood, serum, semen, urine, and preputial wash samples were obtained, in weekly intervals for 1 month, from eight rams belonging to a B. ovis-free flock. Semen samples were also obtained from rams belonging to naturally infected flocks (n=40). The limit of detection of this PCR protocol was 100, 10, and 1 CFU/mL for semen, urine and prepucial wash samples, respectively. Sensitivity and specificity values obtained with this PCR method were similar to that of bacteriology when evaluating biological samples. Agreement between PCR and bacteriology results was greater than 90%. These results clearly indicate that this species-specific PCR method is highly efficient for the diagnosis of B. ovis infection in semen, urine, preputial wash and tissue samples from infected rams.