Ogilvie T H, Butler D G, Gartley C J, Dohoo I R
Can J Comp Med. 1983 Apr;47(2):108-11.
A study was designed to compare the metabolic alkalosis produced in cattle from the use of an antacid (magnesium oxide) and a saline cathartic (magnesium sulphate). Six, mature, normal cattle were treated orally with a magnesium oxide (MgO) product and one week later given a comparable cathartic dose of magnesium sulphate (MgSO(4)). The mean percent dry matter content of the cattle feces changed significantly (P<0.001) following administration of both MgO (15.6-8.1) and MgSO(4) (17.0-8.7) but there was no significant difference between treatments. The mean rumen pH values changed significantly (P<0.001) following administration of both MgO (7.-8.7) and MgSO(4) (7.3-8.3) but there was no significant difference between treatments. However, use of the MgO product caused a more severe (P<0.001) metabolic alkalosis as determined by base excess values. The base excess values remained elevated for 24 hours in the MgO treated group compared to only 12 hours after MgSO(4) administration. Following MgO administration, mean hydrogen ion concentration (pH), bicarbonate ion concentration ([HCO(3)-]) and base excess were 7.44, 33.3 mmol/L and +8.0 respectively compared to 7.38, 27 mmol/L and +3.0 after MgSO(4). Since the oral use of MgO in normal cattle causes a greater and more prolonged metabolic alkalosis compared to MgSO(4), MgO is contraindicated as a cathartic in normal cattle or in cattle with abomasal abnormalities characterized by pyloric obstruction and metabolic alkalosis.
一项研究旨在比较使用抗酸剂（氧化镁）和盐类泻药（硫酸镁）给牛造成的代谢性碱中毒情况。六头成熟、健康的牛口服一种氧化镁（MgO）产品，一周后给予剂量相当的硫酸镁（MgSO₄）泻药。给予氧化镁（MgO）（从15.6降至8.1）和硫酸镁（MgSO₄）（从17.0降至8.7）后，牛粪便的平均干物质含量百分比均有显著变化（P<0.001），但两种处理之间无显著差异。给予氧化镁（MgO）（从7.0升至8.7）和硫酸镁（MgSO₄）（从7.3升至8.3）后，瘤胃平均pH值均有显著变化（P<0.001），但两种处理之间无显著差异。然而，根据碱剩余值判断，使用氧化镁产品导致更严重的（P<0.001）代谢性碱中毒。与给予硫酸镁（MgSO₄）后仅12小时相比，氧化镁处理组的碱剩余值在24小时内一直升高。给予氧化镁后，平均氢离子浓度（pH）、碳酸氢根离子浓度（[HCO₃⁻]）和碱剩余分别为7.44、33.3 mmol/L和 +8.0，而给予硫酸镁（MgSO₄）后分别为7.38、27 mmol/L和 +3.0。由于正常牛口服氧化镁比口服硫酸镁会导致更严重且持续时间更长的代谢性碱中毒，因此氧化镁禁忌作为泻药用于正常牛或患有以幽门梗阻和代谢性碱中毒为特征的皱胃异常的牛。
