Ocorrência de anticorpos para os agentes de doenças infecciosas de importância sanitária em rebanhos leiteiros

Abstract

According to the Ministry of Agriculture, Livestock and Supply (MAPA), Brazil has the largest commercial cattle herd in the world and is the fourth largest milk producer. According to IBGE (2022), bed production in Brazil exceeded 35 billion liters. Despite this favorable scenario, production rates are lower than other countries with lower production, mainly due to infectious agents that negatively impact the reproductive efficiency of herds. Several infectious agents such as bacteria, viruses and protozoa are known for their impact on the reproductive health of livestock. Many of these diseases, in addition to reproductive problems, cause great economic losses in dairy herds, reaching great importance in animal health. Therefore, the objective of this work was to verify the occurrence of antibodies to the causative agents of Brucellosis, Leptospirosis, Enzootic Bovine Leucosis (EBL) and Paratuberculosis in dairy cattle herds in the Lavras region and within a maximum radius of 120 km from the Federal University of Lavras (UFLA), associating it with the main risk factors for diseases in the region. Fifty-four rural properties were visited, collecting blood samples from lactating dairy cows for serological examination for each disease studied and carrying out an epidemiological interview on each property, with questions related to production characteristics and sanitary practices. With the answers to the questionnaire, the farms were characterized in terms of their breeding system, reproductive and health management, presence of other animal species on the property, movement of animals and the occurrence of diseases on the property. In this study, the disease with the highest occurrence in the properties studied was LBE, with 96.29% of properties positive for the agent and with a prevalence of 73.89% of positive animals within the herds studied. leptospirosis and paratberculosis were diseases in which a high occurrence was observed on properties with 87.04% and 72.22% respectively. While brucellosis was the disease that had the lowest occurrence on properties, 9.26%, and also had the lowest prevalence within herds, just 1.37% of animals. The vast majority of properties showed occurrence for at least 2 agents studied (52/54), and it was observed that some predisposing factors for the occurrence of diseases were common to them. It was observed that the use of bulls in reproduction, the occurrence of abortion and the destination of these fetal remains, the introduction of animals and their previous testing were some factors common to all the diseases studied, showing that changes in management can lead to good results. results in controlling these diseases.