Division of Animal Sciences, University of Missouri, Columbia, MO, USA.
Department of Veterinary Medicine and Epidemiology, University of California, Davis, CA, USA.
Theriogenology. 2022 Aug;188:145-155. doi: 10.1016/j.theriogenology.2022.05.024. Epub 2022 May 30.
To determine changes in suckling neonatal beef calf blood chemistry and body temperature during the first 72 h of life, jugular blood samples and rectal temperatures were obtained from 24 healthy, fall-born Angus-cross and Hereford calves (average calving date = September 11) at 0 (after standing, but pre-suckling), 6, 12, 24, 48, and 72 h postnatally. Serum chemistry panels were conducted, and plasma triglycerides and serum non-esterified fatty acids (NEFA) were also determined. Data were analyzed using sampling hour as a repeated effect, and individual data points were compared to adult bovine reference intervals. All serum chemistry measures were affected by hour of age except bicarbonate (P = 0.48). Serum glucose, total protein, and globulin concentrations increased (P < 0.001) from 0 to 24 h. Plasma triglycerides increased (P < 0.001) from 0 to 6 h and 24 to 72 h. Serum urea nitrogen increased (P < 0.001) from 0 to 6 h and decreased (P = 0.01) from 48 to 72 h. Serum NEFA and creatine kinase (CK) increased (P < 0.001) from 0 to 6 h, but decreased (P ≤ 0.02) from 12 to 72 h. Serum magnesium, aspartate aminotransferase (AST), and total and direct bilirubin increased (P < 0.001) during the first 12 h, then decreased (P < 0.001) from 24 to 72 h. Gamma-glutamyl transpeptidase (GGT) increased (P < 0.001) from 0 to 12, and then decreased (P < 0.003) from 12 to 48 h. Serum creatinine decreased (P < 0.001) from 0 to 72 h, and albumin decreased (P < 0.01) from 0 to 12 h but increased (P < 0.001) from 24 to 48 h. Anion gap decreased (P ≤ 0.05) from 6 to 24 h. No serum components measured were within adult bovine reference intervals for all calves at all sampling times. All serum albumin concentrations were outside of reference intervals, and the majority of serum glucose, calcium, phosphorus, potassium, CK, GGT, and total bilirubin were outside of reference intervals. More serum chemistry measures diverged from reference intervals in the first 24 h of neonatal life. Rectal temperature decreased (P = 0.003) from 0 to 6 h of age, then increased (P ≤ 0.02) from 12 to 48 h. In summary, blood chemistry profiles of healthy, suckling neonatal beef calves change over the first 72 h of life, indicating rapid changes in metabolism and physiology. Bovine reference intervals based on adults do not appear to represent neonatal calves; thus, neonatal status and animal age should be taken into consideration when interpreting serum chemistry in a clinical or research setting.
为了确定哺乳期新生安格斯杂交和海弗牛犊牛在出生后前 72 小时内的哺乳行为对血液化学和体温的影响，在出生后 0（站立后但未哺乳前）、6、12、24、48 和 72 小时，从 24 头健康的秋季出生的安格斯杂交和海弗牛犊牛中采集颈静脉血样和直肠温度。进行血清化学分析，并测定血浆甘油三酯和血清非酯化脂肪酸（NEFA）。使用采样时间作为重复效应进行数据分析，并将各时间点的数据与成年牛的参考区间进行比较。除了碳酸氢盐（P=0.48）外，所有血清化学指标均受小时数的影响。血清葡萄糖、总蛋白和球蛋白浓度在 0 至 24 小时内增加（P<0.001）。血浆甘油三酯在 0 至 6 小时和 24 至 72 小时之间增加（P<0.001）。血清尿素氮在 0 至 6 小时之间增加（P<0.001），48 至 72 小时之间减少（P=0.01）。血清 NEFA 和肌酸激酶（CK）在 0 至 6 小时之间增加（P<0.001），但在 12 至 72 小时之间减少（P≤0.02）。血清镁、天门冬氨酸氨基转移酶（AST）和总胆红素和直接胆红素在最初的 12 小时内增加（P<0.001），然后从 24 至 72 小时之间减少（P<0.001）。γ-谷氨酰转肽酶（GGT）在 0 至 12 小时之间增加（P<0.001），然后在 12 至 48 小时之间减少（P<0.003）。血清肌酐在 0 至 72 小时之间减少（P<0.001），白蛋白在 0 至 12 小时之间减少（P<0.01），但在 24 至 48 小时之间增加（P<0.001）。阴离子间隙在 6 至 24 小时之间减少（P≤0.05）。在所有采样时间点，所有小牛的所有血清成分均不在成年牛的参考区间内。所有血清白蛋白浓度均超出参考区间，大多数血清葡萄糖、钙、磷、钾、CK、GGT 和总胆红素均超出参考区间。在新生儿生命的前 24 小时内，更多的血清化学指标与参考区间不符。直肠温度在 0 至 6 小时之间减少（P=0.003），然后在 12 至 48 小时之间增加（P≤0.02）。总之，健康哺乳的新生安格斯杂交和海弗牛犊牛的血液化学特征在生命的前 72 小时内发生变化，表明新陈代谢和生理学发生了快速变化。基于成年动物的牛参考区间似乎不能代表新生小牛；因此，在临床或研究环境中解释血清化学时，应考虑新生状态和动物年龄。
