Yamagishi Norio, Kawashima Chiho
Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka599-8531, Japan.
Division of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido080-8555, Japan.
J Dairy Res. 2022 Mar 15:1-9. doi: 10.1017/S0022029922000218.
We investigated whether prepartum levels of serum bone biomarkers are related to the degree of parturient hypocalcaemia and risk of milk fever (MF) in dairy cows with advancing parity. A total of 58 late-pregnant cattle were assigned to four groups: nulliparous, primiparous, multiparous in the 2nd lactation and multiparous in the 3rd-5th lactation. The multiparous cows were further assigned to MF and non-MF groups according to the onset of MF. Serum samples were obtained from the cows during the 3 weeks prepartum to 5 d postpartum period for the measurement of serum calcium (Ca) and three bone biomarkers: tartrate-resistant acid phosphatase isoform 5b (TRAP5b), osteoprotegerin (OPG) and bone isoenzyme of alkaline phosphatase (ALP3). The ratios of OPG to TRAP5b (O/T ratio) and ALP3 to TRAP5b (A/T ratio) were calculated. The data from all cattle showed that the severity of hypocalcaemia at parturition increased with advancing parity/age. The MF cows had elevated serum TRAP5b activity and a decreased O/T ratio after parturition, suggesting an increased number of osteoclasts due to osteoclastogenesis, in response to severe hypocalcaemia. The MF cows showed lower serum ALP3 activity during the 3 weeks prepartum than the non-MF cows, therefore, prepartum osteoblast function was likely weak in the MF cows. During the 2-3 weeks prepartum, serum ALP3 activity and the A/T ratio had moderate associations with the serum Ca concentration at day 0 (day of calving) in the multiparous cows, and receiver operating characteristic curve analysis revealed that ALP3 activity had excellent ability to predict MF. In conclusion, prepartum serum ALP3 activity is a promising biomarker to predict MF in multiparous cows.
我们研究了随着胎次增加，奶牛产前血清骨生物标志物水平是否与产犊母牛低钙血症程度及产乳热（MF）风险相关。总共58头妊娠后期母牛被分为四组：未产母牛、初产母牛、第二胎经产母牛和第三至五胎经产母牛。经产母牛根据产乳热发病情况进一步分为产乳热组和非产乳热组。在产前3周至产后5天期间采集母牛血清样本，用于测定血清钙（Ca）和三种骨生物标志物：抗酒石酸酸性磷酸酶同工型5b（TRAP5b）、骨保护素（OPG）和骨碱性磷酸酶同工酶（ALP3）。计算OPG与TRAP5b的比值（O/T比值）以及ALP3与TRAP5b的比值（A/T比值）。所有母牛的数据显示，分娩时低钙血症的严重程度随着胎次/年龄的增加而增加。产乳热母牛产后血清TRAP5b活性升高，O/T比值降低，这表明由于破骨细胞生成增加，对严重低钙血症产生反应，破骨细胞数量增多。产乳热母牛在产前3周的血清ALP3活性低于非产乳热母牛，因此，产乳热母牛的产前成骨细胞功能可能较弱。在产前2 - 3周，经产母牛的血清ALP3活性和A/T比值与产犊日（第0天）的血清钙浓度呈中度相关，受试者工作特征曲线分析显示，ALP3活性具有出色的预测产乳热的能力。总之，产前血清ALP3活性是预测经产母牛产乳热的一个有前景的生物标志物。
