RESUMEN

Bovine genital leptospirosis is a chronic disease that causes reproductive disorders such as abortions, stillbirths, and estrus repetition, as well as economic losses. Despite clinical signs related to reproductive failure, the majority of studies have focused on the detection of Leptospira spp. in the urine, while few have considered the reproductive tract. Consequently, the aim of the present study was to investigate the uterus as an important extra-renal site of leptospiral infection in cows. A total of 42 non-pregnant cows were studied at a slaughterhouse. Blood samples and uterine fragments were collected for serology and molecular analysis, respectively. Concerning serologic results, 20.5 % presented as reactive, all of them against the Sejroe serogroup. Regarding lipL32 PCR, 26.2 % (11/42) of samples were positive for pathogenic Leptospira sp. Sequencing the secY gene short region enabled nine strains to be characterized, all of which were L. interrogans, with high identity (98.8 %-99.8 %) with serovar Hardjo. The use of molecular tools substantially improved the sensitivity of Leptospira sp. detection at species level and demonstrated that the uterus is an important site of bovine leptospiral infection. The findings of the present study reinforce our understanding that leptospiral uterine infection are associated to members of the Sejroe serogroup.

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RESUMEN

Reproductive efficiency is one of the key elements for any milk production system to be successful. In this regard, reproductive management must be planned properly and the identification of the main reproductive disorders that affect the herd is primordial for decision-making. The aim of the present study was to identify the main reproductive problems that affect dairy herds on Rio de Janeiro (RJ), Brazil. Data regarding breed, age, reproductive disorder occurrence, and breeding system were individually collected from dairy cows raised at 25 farms located at RJ. The occurrence of reproductive disorders was reported in 37% of the studied animals. Estrous repetition (76.2%) and abortion (15.6%) were the most frequent reproductive problems reported. Estrous repetition was more common in older animals (>6 years old). However, an association between abortion and age of animal was not observed, nor an association between breeding system and occurrence of abortion. The present results demonstrated that estrous repetition is the main obstacle to the reproductive efficiency in dairy herds at RJ, and that the replace of older cows by heifers is an important point within reproductive management of a dairy herd.

A eficiência reprodutiva é um dos principais elementos para qualquer sistema de produção de leite ser bem-sucedida. Neste contexto, o manejo reprodutivo deve ser planejado adequadamente e a identificação das principais desordens reprodutivas que afetam o rebanho é essencial para a tomada de decisão. O objetivo do presente estudo foi identificar os principais problemas reprodutivos que acometem rebanhos leiteiros no Rio de Janeiro (RJ), Brasil. Dados relacionados com a raça, idade, ocorrência de problema reprodutivo e o sistema de acasalamento foram individualmente coletados de vacas leiteiras criadas em 25 fazendas localizadas no RJ. A ocorrência de desordens reprodutivas foi relatada em 37% dos animais estudados. A repetição de estro (76,2%) e abortamento (15,6%) foram os problemas reprodutivos mais frequentemente relatados. A repetição de estro foi mais comum em animais mais velhos (>6 anos). Contudo, uma associação entre abortamento e idade do animal não foi observada, nem uma associação entre o sistema de acasalamento e a ocorrência abortamento. Os presentes resultados demonstraram que a repetição de estro é o principal obstáculo para a eficiência reprodutiva nos rebanhos leiteiros do RJ, e que a substituição de animais mais velhos por novilhas é um importante ponto dentro do manejo reprodutivo de um rebanho leiteiro.

Asunto(s)

RESUMEN

Reproductive efficiency is one of the key elements for any milk production system to be successful. In this regard, reproductive management must be planned properly and the identification of the main reproductive disorders that affect the herd is primordial for decision-making. The aim of the present study was to identify the main reproductive problems that affect dairy herds on Rio de Janeiro (RJ), Brazil. Data regarding breed, age, reproductive disorder occurrence, and breeding system were individually collected from dairy cows raised at 25 farms located at RJ. The occurrence of reproductive disorders was reported in 37% of the studied animals. Estrous repetition (76.2%) and abortion (15.6%) were the most frequent reproductive problems reported. Estrous repetition was more common in older animals (>6 years old). However, an association between abortion and age of animal was not observed, nor an association between breeding system and occurrence of abortion. The present results demonstrated that estrous repetition is the main obstacle to the reproductive efficiency in dairy herds at RJ, and that the replace of older cows by heifers is an important point within reproductive management of a dairy herd.(AU)

A eficiência reprodutiva é um dos principais elementos para qualquer sistema de produção de leite ser bem-sucedida. Neste contexto, o manejo reprodutivo deve ser planejado adequadamente e a identificação das principais desordens reprodutivas que afetam o rebanho é essencial para a tomada de decisão. O objetivo do presente estudo foi identificar os principais problemas reprodutivos que acometem rebanhos leiteiros no Rio de Janeiro (RJ), Brasil. Dados relacionados com a raça, idade, ocorrência de problema reprodutivo e o sistema de acasalamento foram individualmente coletados de vacas leiteiras criadas em 25 fazendas localizadas no RJ. A ocorrência de desordens reprodutivas foi relatada em 37% dos animais estudados. A repetição de estro (76,2%) e abortamento (15,6%) foram os problemas reprodutivos mais frequentemente relatados. A repetição de estro foi mais comum em animais mais velhos (>6 anos). Contudo, uma associação entre abortamento e idade do animal não foi observada, nem uma associação entre o sistema de acasalamento e a ocorrência abortamento. Os presentes resultados demonstraram que a repetição de estro é o principal obstáculo para a eficiência reprodutiva nos rebanhos leiteiros do RJ, e que a substituição de animais mais velhos por novilhas é um importante ponto dentro do manejo reprodutivo de um rebanho leiteiro.(AU)

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Leptospirosis is an important cause of reproductive failure in cattle. The standard diagnostic tool (MAT) is recommended for herd but not for individual diagnosis. The aim of this study was to evaluate the humoral response of bovines face to their own recovered isolates. A total of 25 bovine from which leptospires were recovered were tested by MAT against reference strains and their own isolates. Only three cows (12%) presented seroreactivity against their own isolates. This study demonstrates that cattle may not react against their own isolates and highlights the importance of interpreting serological negative results with caution.

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Leptospirosis is a worldwide zoonosis which can affect many species. Control programs need accurate diagnosis to be successful, and currently, diagnosis relies on serology. It presents three main issues: the sampling, the antigen panel, and the cutoff point. Herein, we propose a systematic review on leptospirosis among dogs, pigs, and horses in Latin America in order to improve the understanding of the seroepidemiology of leptospirosis in these species in the region as well as the temporal development of the research on this topic and, consequently, improve the chances of success on control programs. Internet databases were consulted over 2015. Inclusion criteria included serosurvey using MAT; a relevant number of animals; the presence in the antigen panel of at least one representative of serogroups Icterohaemorrhagiae and Canicola for dogs, Icterohaemorrhagiae, Australis, and Pomona for pigs, and Icterohaemorrhagiae and Australis for horses; and a cutoff point of ≥100. Overall, 240 papers were studied, of which 87 referred to dogs, 66 to pigs, 39 to horses, and 48 to more than one of the studied species. In relation to those that met all the inclusion criteria, it was 45 (66.2%) in dogs, 23 (41.8%) in pigs, and 23 (63.9%) in horses. Leptospirosis is widespread in Latin America. Predominant serogroups are Canicola to dogs and Icterohaemorrhagiae to pigs and horses. Therefore, research on animal leptospirosis should be encouraged in Latin America, in order to reach a greater standardization in studies and then achieve better results on control programs.

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ABSTRACT: Reproductive efficiency is one of the key elements for any milk production system to be successful. In this regard, reproductive management must be planned properly and the identification of the main reproductive disorders that affect the herd is primordial for decision-making. The aim of the present study was to identify the main reproductive problems that affect dairy herds on Rio de Janeiro (RJ), Brazil. Data regarding breed, age, reproductive disorder occurrence, and breeding system were individually collected from dairy cows raised at 25 farms located at RJ. The occurrence of reproductive disorders was reported in 37% of the studied animals. Estrous repetition (76.2%) and abortion (15.6%) were the most frequent reproductive problems reported. Estrous repetition was more common in older animals (>6 years old). However, an association between abortion and age of animal was not observed, nor an association between breeding system and occurrence of abortion. The present results demonstrated that estrous repetition is the main obstacle to the reproductive efficiency in dairy herds at RJ, and that the replace of older cows by heifers is an important point within reproductive management of a dairy herd.

RESUMO: A eficiência reprodutiva é um dos principais elementos para qualquer sistema de produção de leite ser bem-sucedida. Neste contexto, o manejo reprodutivo deve ser planejado adequadamente e a identificação das principais desordens reprodutivas que afetam o rebanho é essencial para a tomada de decisão. O objetivo do presente estudo foi identificar os principais problemas reprodutivos que acometem rebanhos leiteiros no Rio de Janeiro (RJ), Brasil. Dados relacionados com a raça, idade, ocorrência de problema reprodutivo e o sistema de acasalamento foram individualmente coletados de vacas leiteiras criadas em 25 fazendas localizadas no RJ. A ocorrência de desordens reprodutivas foi relatada em 37% dos animais estudados. A repetição de estro (76,2%) e abortamento (15,6%) foram os problemas reprodutivos mais frequentemente relatados. A repetição de estro foi mais comum em animais mais velhos (>6 anos). Contudo, uma associação entre abortamento e idade do animal não foi observada, nem uma associação entre o sistema de acasalamento e a ocorrência abortamento. Os presentes resultados demonstraram que a repetição de estro é o principal obstáculo para a eficiência reprodutiva nos rebanhos leiteiros do RJ, e que a substituição de animais mais velhos por novilhas é um importante ponto dentro do manejo reprodutivo de um rebanho leiteiro.

RESUMEN

The diagnosis of leptospirosis commonly relies on serology, which has three issues that are referred: the sampling, the antigen panel, and the cutoff point. We propose a systematic review of the bovine leptospirosis in Latin America, in order to provide a better understanding of the evolution of the research and of the seroepidemiology of bovine leptospirosis in that region. Internet databases were consulted over the year of 2014. Inclusion criteria for analysis included serosurvey using microscopic agglutination test (MAT), a relevant number of animals, the presence in the antigen panel of at least one representant of serogroup Sejroe, and a cutoff point of ≥100. A total of 242 articles that referred to cattle, leptospir*, and one region of Latin America was found. Only 105 articles regarding to serosurveys using MAT were found in several countries, and 61 (58.1 %) met all the inclusion criteria. In conclusion, this systematic review demonstrated a high prevalence of the infection (75.0 % at herd level and 44.2 % at animal level), with predominance of strains of serogroup Sejroe (80.3 %). It was evident that there is the necessity of more studies in several countries, as well as the need for greater standardization in studies, especially with regard to the adopted cutoff point at serological tests.

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