RESUMO
The transplacental transmission of parasites and hemoparasites is crucial for understanding the epidemiology of diseases. This study aimed to assess the prevalence of hemopathogens in bovine fetuses at various gestational periods. Samples were obtained from a slaughterhouse in the state of Minas Gerais, Brazil, and a total of 236 fetuses were collected. DNA extracted from blood samples (145) and organ samples (a pool of brain and spleen) (236) underwent a nested PCR (nPCR) assay to detect Babesia spp., Theileria spp., Trypanosoma vivax, Anaplasma marginale, Anaplasma bovis, Anaplasma phagocytophilum, Ehrlichia minasensis, and hemotropic Mycoplasma spp. Additionally, serological analysis of 145 plasma samples was conducted using the indirect fluorescent antibody test-IFAT to detect IgG against Babesia bovis, Babesia bigemina, A. marginale, and Trypanosoma vivax. The observed prevalence of transplacental transmission was 19.3 %, 6.2 %, 42.7 % and 2.7 %, for A. marginale, B. bigemina, 'Candidatus M. haemobos', and Mycoplasma wenyonii, respectively. The prevalence of A. marginale by gestational trimester was 16 % (13/81) in the second trimester and 23 % (14/60) in the third trimester, with no positive samples in the first trimester. Regarding the species B. bovis and B. bigemina, all evaluated animals tested negative by nPCR, and no serological evidence for B. bovis was found by the IFAT. Babesia bigemina demonstrated an overall seroprevalence of 6.2 % (9/145), with 4.8 % (7/145) in the last trimester and 1.3 % (2/145) in the second trimester of pregnancy. In total, 42.7 % (62/145) of blood samples were positive for 'Candidatus M. haemobos', with 42 % (34/81) in the middle trimester, and 43 % (26/60) in the final trimester of pregnancy. Mycoplasma wenyonni was detected in 2.7 % (4/145) blood samples, all in coinfection with 'C. M. haemobos'. The prevalence by pregnancy trimester was 25 % (1/4) in the first trimester; 1.2 % (1/81) in the second trimester and 3.3 % (2/60) in the third trimester of pregnancy. Hemopathogen DNA was detected in fetus blood samples but not the brain or spleen samples. All the samples were negative for T. vivax, Theileria spp., Anaplasma spp. and Ehrlichia spp. Overall, in this study, approximately 70 % of fetuses were positive for one or more of the studied parasites. No significant associations were observed between pairs of pathogens, except 'C. M. haemobos' and A. marginale.
Assuntos
Doenças dos Bovinos , Mycoplasma , Animais , Brasil/epidemiologia , Bovinos , Feminino , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Mycoplasma/isolamento & purificação , Gravidez , Prevalência , Babesia/isolamento & purificação , Feto/microbiologia , Feto/parasitologia , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/veterinária , Infecções por Mycoplasma/microbiologia , Theileria/isolamento & purificação , Trypanosoma vivax/isolamento & purificação , Transmissão Vertical de Doenças Infecciosas/veterinária , Anaplasma/isolamento & purificação , Babesiose/epidemiologia , Babesiose/parasitologia , Anaplasmose/epidemiologia , Anaplasmose/microbiologia , Ehrlichia/isolamento & purificaçãoRESUMO
A claudicação é considerada uma das três ocorrências mais comuns na bovinocultura de leite, juntamente com a mastite e os problemas reprodutivos. A claudicação é um sinal de dor, o que indica prejuízo ao bem- -estar animal, além de redução na produção de leite, aumento da chance de descarte precoce e piora do desempenho reprodutivo. De acordo com Silva et al. (2006), as afecções relacionadas ao sistema locomotor são a segunda maior causa de descarte de um rebanho bovino (18,5%), ficando atrás apenas dos problemas reprodutivos (27,7%). Apesar dos avanços no conhecimento das práticas de controle e tratamento da claudicação, sua frequência não diminuiu ao longo do tempo e, embora improvável, aparentemente está aumentando e hoje atinge prevalência inaceitável. No Brasil, a situação não é diferente e a incidência de claudicação é preocupante. Ferreira (2003) avaliou uma propriedade de sistema free-stall em um período de um ano e descreveu que a incidência de animais claudicantes foi de 122%, ou seja, alguns animais tiveram mais de um caso de claudicação durante o período. Já Costa et al. (2018), ao avaliarem a prevalência de claudicação em rebanhos alojados em sistema de free- -stall, compost barn e sistema de free-stall + compost barn, localizados no estado do Paraná, relatou que, de forma geral, a prevalência de claudicação foi de 42,5%. Estudos em rebanhos de bovinos de leite a pasto em Minas Gerais e no Paraná mostram prevalência não menos preocupantes, variando de 5 a 76% nos rebanhos estudados. Essas dificuldades enfrentadas evidenciam a necessidade de que, para conseguir melhorar a saúde do casco, também são necessárias pesquisas que trabalhem fatores socioeconômicos, entendendo a realidade e as dificuldades que os produtores enfrentam para controlar as doenças podais. Para que se possa realizar qualquer mudança no intuito de diminuir as afecções podais, é preciso uma motivação de todos os envolvidos nesse sentido e o conhecimento dos entraves que podem impedir a progressão do problema.(AU)
Assuntos
Animais , Feminino , Bovinos/anatomia & histologia , Casco e Garras/diagnóstico por imagem , Claudicação Intermitente/históriaRESUMO
Several direct or indirect methods can be used to assess immunoglobulin G (IgG) concentrations in calves, which evaluates the transfer of passive immunity (TPI). Radial immunodiffusion (RID) is the gold standard method to measure serum IgG in bovines. Previous studies have shown that colostrum provides several molecules in addition to immunoglobulins, which play an important role in the passive immunity of the calf. However, no studies have yet determined the level of interference of these components in the immunity, health and survival of calves. In this sense, the objective of this study is to review the methods of evaluation available for the laboratory and field diagnosis of TPI in calves and discuss the main aspects of each technique. Several methods available for TPI evaluation in calves may provide insights into the various components of colostrum involved in passive immunity.
RESUMO
The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average initial BW of 435.1 kg at 180, 210 and 240 days of gestation, obtained using respirometry. Twelve animals in two groups (six per genetic group) received a restricted diet equivalent to 1.3 times the net energy for maintenance (NEm). The proportion of gross energy intake (GEI) lost as feces did not differ between the evaluated breeds and corresponded to 28.65% on average. The daily methane production (L/d) was greater for (P<0.05) F1 HxG compared to Gyr animals. However, when expressed as L/kg dry matter (DM) or as percentage of GEI there were no differences between the groups (P>0.05). The daily loss of energy as urine (mean of 1.42 Mcal/d) did not differ (P>0.05) between groups and ranged from 3.87 to 5.35% of the GEI. The metabolizable energy intake (MEI) of F1 HxG animals was greater (P < 0.05) at all gestational stages compared to Gyr cows when expressed in Mcal/d. However, when expressed in kcal/kg of metabolic BW (BW0,75), the F1 HxG cows had MEI 11% greater (P<0.05) at 240 days of gestation and averaged 194.39 kcal/kg of BW0,75. Gyr cows showed no change in MEI over time (P>0.05), with a mean of 146.66 kcal/kg BW0. 75. The ME used by the conceptus was calculated by deducting the metabolizable energy for maintenance (MEm) from the MEI, which was obtained in a previous study using the same cows prior to becoming pregnant. The values of NEm obtained in the previous study with similar non-pregnant cows were 92.02 kcal/kg BW0.75 for F1 HxG, and 76.83 kcal/kg BW0.75 for Gyr (P = 0.06). The average ME for pregnancy (MEp) was 5.33 Mcal/d for F1 HxG and 4.46 Mcal/d for Gyr. The metabolizability ratio, averaging 0.60, was similar among the evaluated groups (P>0.05). The ME / Digestible Energy (DE) ratio differed between groups and periods evaluated (P<0.05) with a mean of 0.84. The heat increment (HI) accounted for 22.74% and 24.38% of the GEI for F1 HxG and Gyr cows, respectively. The proportion of GEI used in the basal metabolism by pregnant cows in this study represented 29.69%. However, there were no differences between the breeds and the evaluation periods and corresponded to 29.69%. The mean NE for pregnancy (NEp) was 2.76 Mcal/d and did not differ between groups and gestational stages (P>0.05).