Jørgensen R J, Nyengaard N R, Hara S, Enemark J M, Andersen P H
Cattle Research Group, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
Acta Vet Scand. 1998;39(3):331-8. doi: 10.1186/BF03547781.
Rumen motility was recorded on an experimental cow by means of telemetric signal transfer from strain gauge force transducers fixed surgically on the peritoneal surface of the rumen wall in the left flank. The normocalcaemic cow was given a standard milk fever treatment with calcium borogluconate (400 ml with 14 mg Ca/ml) intravenously. Transient clinical signs were: decreased rumination, muscle ticks, salivation and a heart rate reduction of 20%. Rectal temperature remained unaltered. Frequency of rumen contractions was reduced up to 40% whereas amplitude of contractions did not deviate from baseline values. Hypocalcaemia was induced in a second experiment by iv infusion of Na2EDTA. At 0.60 mmol/l ionized blood calcium periods of no motility were recorded whereas inactivity of rumen activity was persistent at 0.55 mmol/l ionized blood calcium. The cow went down at 0.45-0.48 mmol/l ionized blood calcium at which point the heart rate was increased by 40%. The high sensitivity of the method employed allowed the conclusion that already at a concentration of ionized blood calcium at 1.0 mmol/l both frequency and amplitude of rumen contractions decreased rapidly although eating behaviour and rumination appeared unaffected during the short term observation periods. Implications of this finding towards health and production in transition cows are discussed.
通过将应变片式力传感器手术固定在左侧胁腹瘤胃壁腹膜表面，并借助遥测信号传输，记录了一头实验奶牛的瘤胃蠕动情况。给血钙正常的奶牛静脉注射标准的葡萄糖酸钙（400毫升，含钙14毫克/毫升）进行乳热治疗。短暂的临床症状包括：反刍减少、肌肉抽搐、流涎以及心率降低20%。直肠温度未发生变化。瘤胃收缩频率降低了40%，而收缩幅度与基线值无偏差。在第二个实验中，通过静脉输注乙二胺四乙酸二钠（Na2EDTA）诱发低钙血症。当血钙离子浓度为0.60毫摩尔/升时，记录到瘤胃无蠕动期，而当血钙离子浓度为0.55毫摩尔/升时，瘤胃活动持续不活跃。当血钙离子浓度降至0.45 - 0.48毫摩尔/升时，奶牛卧倒，此时心率增加了40%。所采用方法的高灵敏度使得得出以下结论：尽管在短期观察期内采食行为和反刍似乎未受影响，但当血钙离子浓度为1.0毫摩尔/升时，瘤胃收缩的频率和幅度均迅速下降。本文讨论了这一发现对围产奶牛健康和生产的影响。
