Diagnóstico de mastites subclínicas em caprinos
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2016-04-05
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Existem vários métodos disponíveis para o diagnóstico de mastites subclínicas. No entanto, é necessário ter em consideração que há diferenças entre espécies, principalmente no que diz respeito às contagens de células somáticas. Assim, a extrapolação dos resultados verificados em ovinos e bovinos pode conduzir a erros na deteção de casos de inflamação da glândula mamária em caprinos. Com este estudo pretendeu-se avaliar, comparativamente, a utilidade da contagem bacteriana por cultura (PCA-Plate Count Agar), do Teste Californiano de Mastites (TCM), da contagem de células somáticas pelo método fluoro-opto-eletrónico (Fossomatic) e do doseamento de Amilóide A do leite através de um ensaio imunoenzimático no diagnóstico de mastites em caprinos. Adicionalmente, estimou-se a ocorrência de mastites subclínicas segundo o número de lactações dos animais e a influência do número de partos na contagem de células somáticas. Avaliou-se, ainda, a variação das contagens destas células durante o período em que decorreu o estudo. Para a realização deste trabalho foram utilizadas 144 amostras, correspondentes a uma metade mamária de 12 cabras Serranas, recolhidas semanalmente, durante 6 semanas consecutivas, no período da manhã e previamente à ordenha. O número de metades mamárias infetadas obtido foi de 37 (25,7%). Verificou-se uma associação entre os resultados da cultura e do TCM. Segundo os valores obtidos, as metades mamárias com resultado igual ou superior a 2 são diagnosticadas como infetadas, com uma sensibilidade de 43,2% e especificidade de 77,6%, o que sugere que este teste é mais eficiente em identificar úberes sem infeção do que infetados. A média aritmética da contagem de células somáticas das metades mamárias sem infeção foi superior às infetadas, 3472.000 e 1999.000 células/mL, respetivamente. Já o valor da média geométrica foi superior nas glândulas mamárias com resultado positivo na cultura bacteriana, 1261.000 células/mL, face às que apresentaram resultados negativos, 920.000 células/mL, porém as diferenças encontradas não foram estatisticamente significativas. Os resultados das concentrações de Amilóide A do leite mostraram diferenças significativas entre as glândulas mamárias saudáveis e as que apresentavam mastites subclínicas e entre o grupo com mastites subclínicas inespecíficas e os restantes grupos.
Neste estudo as fêmeas multíparas apresentaram uma ocorrência de infeção intramamária (32%) superior às primíparas (13%). Animais com maior número de lactações revelaram contagens de células somáticas significativamente mais elevadas do que os mais jovens. Todavia, durante o período em decorreu o estudo, não possível verificar uma variação marcada na contagem de células somáticas.
There are several methods available for the diagnosis of subclinical mastitis. However, it is necessary to take into account that there are differences between species, particularly with somatic cells count. Thus, the extrapolation of the results in sheep and cattle can lead to mistakes in detecting cases of inflammation of the mammary gland in goats. The aim of this study was to comparatively evaluate the utility of bacterial counting by culture (PCA-Plate Count Agar), California Mastitis Test (CMT), the somatic cells count by the fluoro-opto-electronic method (Fossomatic), and the measuring of milk Amyloid A through the Enzyme Linked Immuno Sorbent Assay (ELISA) to diagnose mastitis in goats. Additionally, we estimated the occurrence of subclinical mastitis according to the number of lactations and the influence of the number of births in somatic cells count. We also evaluated the variation of these cells counts during the period of the present study. In this study 144 samples were analysed, corresponding to one udder half of 12 Serranas goats, collected weekly for 6 consecutive weeks, in the morning and prior to the milking. The number of infected udder halves was 37 (25.7%). There was an association between the results of the culture and CMT. According to the obtained values, the udder halves results in equal or higher than 2, these are diagnosed as infected with a sensitivity of 43.2% and specificity of 77.6%, suggesting that assay is more efficient to identify healthy udder halves that infected. The arithmetic mean of the somatic cells count of udder halves non-infected was higher comparing to the infected halves, 3472.000 and 1999.000 cells/mL, respectively. The geometric mean was higher in mammary glands with positive results in bacterial culture, 1261.000 cells/mL, comparing to those samples with negative results, 920.000 cells/mL, but the differences were not statistically significant. The results of milk Amyloid A concentrations showed significant differences between healthy mammary glands and mammary glands with subclinical mastitis, and between the group presenting non-specific subclinical mastitis and the other groups. In this study, multiparous females showed an intramammary infection occurrence (32%) higher than the primiparous (13%). Animals with the largest number of lactations revealed a somatic cells count significantly higher than the younger ones. However, during the period of the study, it was not possible to detect an important variation in the somatic cells count.
There are several methods available for the diagnosis of subclinical mastitis. However, it is necessary to take into account that there are differences between species, particularly with somatic cells count. Thus, the extrapolation of the results in sheep and cattle can lead to mistakes in detecting cases of inflammation of the mammary gland in goats. The aim of this study was to comparatively evaluate the utility of bacterial counting by culture (PCA-Plate Count Agar), California Mastitis Test (CMT), the somatic cells count by the fluoro-opto-electronic method (Fossomatic), and the measuring of milk Amyloid A through the Enzyme Linked Immuno Sorbent Assay (ELISA) to diagnose mastitis in goats. Additionally, we estimated the occurrence of subclinical mastitis according to the number of lactations and the influence of the number of births in somatic cells count. We also evaluated the variation of these cells counts during the period of the present study. In this study 144 samples were analysed, corresponding to one udder half of 12 Serranas goats, collected weekly for 6 consecutive weeks, in the morning and prior to the milking. The number of infected udder halves was 37 (25.7%). There was an association between the results of the culture and CMT. According to the obtained values, the udder halves results in equal or higher than 2, these are diagnosed as infected with a sensitivity of 43.2% and specificity of 77.6%, suggesting that assay is more efficient to identify healthy udder halves that infected. The arithmetic mean of the somatic cells count of udder halves non-infected was higher comparing to the infected halves, 3472.000 and 1999.000 cells/mL, respectively. The geometric mean was higher in mammary glands with positive results in bacterial culture, 1261.000 cells/mL, comparing to those samples with negative results, 920.000 cells/mL, but the differences were not statistically significant. The results of milk Amyloid A concentrations showed significant differences between healthy mammary glands and mammary glands with subclinical mastitis, and between the group presenting non-specific subclinical mastitis and the other groups. In this study, multiparous females showed an intramammary infection occurrence (32%) higher than the primiparous (13%). Animals with the largest number of lactations revealed a somatic cells count significantly higher than the younger ones. However, during the period of the study, it was not possible to detect an important variation in the somatic cells count.
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Dissertação de Mestrado Integrado em Medicina Veterinária
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Mastite , Infecções assintomáticas , Contagem de células somáticas , Bactéria , Cultura de células , Amiloide A do leite , Teste californiano de mastites