Blood collection at exsanguination is a method of collecting samples at abattoirs which itself has no effect on animal welfare, compared with collection prior to stunning. However, there is the potential for artefact to affect measurements. It was hypothesised that, for most blood analytes measured, the differences between lairage and exsanguination measurements would be minimal, except for creatine kinase, which was expected be higher in exsanguination samples. Fifty-nine male dairy calves approximately 5-10 days old were sampled prior to slaughter, and again during exsanguination after stunning. Each sample was analysed for packed cell volume, serum urea, beta-hydroxybutyrate, gamma-glutamyl transferase, total protein, glucose and creatine kinase concentrations. Exsanguination and lairage blood results were compared using a paired t-test. There were no significant differences between the measurements taken at exsanguination compared with lairage for packed cell volume, urea and beta-hydroxybutyrate. Glucose concentrations were higher in exsanguination samples, and total protein concentrations were lower, but for both of these analytes the differences were clinically small. Gamma-glutamyl transferase activity was lower in exsanguination samples compared with lairage samples. Creatine kinase activity was higher in exsanguination samples. It was concluded that collecting blood at exsanguination is a valid method for collecting samples for measurement of packed cell volume, urea, and beta-hydroxybutyrate in calves. Glucose and total protein can also yield useful measurements in these samples, though care needs to be taken with interpretation given the minor differences between exsanguination and lairage measurements. Exsanguination samples may be unsuitable for creatine kinase and gamma-glutamyl transferase measurement.

中文翻译：

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屠宰后放血后从牛犊采集的血液与在清扫过程中的体内采集相比，产生了相似的生化和填充细胞体积测量值。

放血采血是一种在屠宰场采血的方法，与在进行惊吓之前采血相比，采血本身对动物的福利没有影响。但是，伪影可能会影响测量。假设，对于大多数测得的血液分析物，乳清和放血测量之间的差异将很小，除了肌酸激酶（放血样品中的肌酸激酶预计会更高）之外。在屠宰前和屠宰后放血期间，对大约5-10天大的59只雄性奶牛进行了采样。分析每个样品的填充细胞体积，血清尿素，β-羟基丁酸酯，γ-谷氨酰转移酶，总蛋白，葡萄糖和肌酸激酶浓度。使用配对t检验比较了放血和血尿的结果。与充血细胞体积，尿素和β-羟基丁酸酯相比，在放血时进行的测量与充血相比没有显着差异。放血样品中的葡萄糖浓度较高，而总蛋白浓度较低，但对于这两种分析物，临床上的差异很小。与挤奶样品相比，放血样品中的γ-谷氨酰转移酶活性较低。放血样品中的肌酸激酶活性较高。结论是放血收集血液是一种有效的方法，可用于收集样品以测量犊牛中的细胞堆积量，尿素和β-羟基丁酸酯。葡萄糖和总蛋白也可以在这些样品中产生有用的测量值，鉴于放血和血统测量之间的微小差异，在解释时需要格外小心。放血样品可能不适合肌酸激酶和γ-谷氨酰转移酶的测量。