Evaluation of a filter system to harvest plasma for total protein measurement in newborn calves of the holstein breed

• Autor(a) principal: Oliveira, Luiza da Costa Corrêa
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/17816
• topic: Calves; Colostrum; Failure of passive transfer; Domínio/Área Científica::Ciências Agrárias::Agricultura, Silvicultura e Pescas

The objective of this study was to evaluate a filter system to harvest plasma in order to assess failure of passive transfer (FPT) in newborn calves. Blood samples (n = 227) were collected from Holstein calves aged 1 to 6 days, from 4 commercial dairy herds in the northeast of Germany. Serum IgG concentration was determined in serum using an ELISA test. Failure of passive transfer was defined as IgG concentrations ≤ 10 mg/mL and used as a gold standard. An optical refractometer and 2 different digital BRIX refractometers were used to assess FPT in serum or plasma. Serum was obtained through centrifugation. Plasma was either obtained through a filter system or centrifugation. A receiver operating characteristic curve analysis was used to determine an optimum threshold for each of the 3 devices using different media. Sixty-seven (30%) calves had FPT. For device 1, the optimum threshold was 8.9% (Se 82.1%; Sp 63.8%; AUC 0.81), 9.4% (Se 76.1%; Sp 73.7%; AUC 0.80), using serum and centrifuged plasma, respectively. For device 2, the optimum threshold was 8.7% (Se 74.6%; Sp 76.2%; AUC 0.83), 9.5% (Se 80.6%; Sp70.6%; AUC 0.83), 9.2% (Se 58.2%; Sp 87.5%; AUC 0.80) using serum, centrifuged plasma, and filtered plasma, respectively. For device 3, the optimum threshold was 5.6 g/dL (Se 70.1%; Sp 80.0%; AUC 0.85), 6.3 g/dL (Se 82.1%; Sp 68.1%; AUC 0.84), 6.0 g/dL (Se 56.7%; Sp 90.0%; AUC 0.80) using serum, centrifuged plasma, and filtered plasma, respectively. Based on AUC the 3 devices yielded comparable test characteristics to identify calves with FPT. In conclusion, a filter system can be used to facilitate the evaluation of FPT as a point of care technique in calves without the need for serum centrifugation.