Sonntag N, Borchardt S, Heuwieser W, Sargent R, Sutter F
Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Königsweg 65, 14163 Berlin, Germany.
The Saskatoon Colostrum Co. Ltd. (SCCL), Saskatoon, SK, Canada, S7K 6A2.
JDS Commun. 2023 Mar 2;4(4):269-273. doi: 10.3168/jdsc.2022-0335. eCollection 2023 Jul.
The objective of the study was to compare 4 different methods of serum collection to assess failed transfer of passive immunity (FTPI) in dairy calves. We hypothesized that centrifuged serum, filtered serum and clotted serum at room temperature, and clotted serum at refrigerator temperature measured with Brix refractometry would highly correlate with IgG concentration assessed by radial immunodiffusion (RID; gold standard) in centrifuged serum. Blood samples were collected from 321 newborn dairy calves. In centrifuged serum (r = 0.88), serum clotted at room temperature (20.2°C ± 6.47; r = 0.86), serum clotted at refrigerator temperature (7.6°C ± 0.91; r = 0.87), and filtered serum (r = 0.70), total solids (TS) in % Brix, and IgG concentrations measured with RID were highly correlated. Regarding the refractometry results among the different serum types, the TS results of serum clotted at room temperature, clotted at refrigerator temperature, and filtered serum showed high correlation coefficients compared with the TS results of centrifuged serum (r = 0.99, r = 0.98, and r = 0.89), respectively. The test characteristics of clotted serum were as accurate as centrifuged serum and generate comparable results. Filtered serum was slightly less accurate. All serum types are valid methods to detect an FTPI in dairy calves, if the specific Brix thresholds for each serum type are considered. Nevertheless, serum clotted at refrigerator temperature should not be the preferred method to avoid the risk of hemolysis.
本研究的目的是比较4种不同的血清采集方法，以评估奶牛犊牛被动免疫失败（FTPI）情况。我们假设，用糖度折射仪测量的室温下的离心血清、过滤血清和凝块血清，以及冷藏温度下的凝块血清，与通过离心血清中的放射免疫扩散法（RID；金标准）评估的IgG浓度高度相关。从321头新生奶牛犊牛采集血样。在离心血清（r = 0.88）、室温（20.2°C ± 6.47；r = 0.86）下凝结的血清、冷藏温度（7.6°C ± 0.91；r = 0.87）下凝结的血清和过滤血清（r = 0.70）中，用糖度表示的总固体（TS）与用RID测量的IgG浓度高度相关。关于不同血清类型的折射仪结果，室温下凝结的血清、冷藏温度下凝结的血清和过滤血清的TS结果与离心血清的TS结果相比，显示出较高的相关系数（分别为r = 0.99、r = 0.98和r = 0.89）。凝块血清的检测特性与离心血清一样准确，并产生可比的结果。过滤血清的准确性略低。如果考虑每种血清类型的特定糖度阈值，所有血清类型都是检测奶牛犊牛FTPI的有效方法。然而，冷藏温度下凝结的血清不应作为首选方法，以避免溶血风险。
