Clinico-Pharmacological Studies of 1,25(OH)_2D_3 to Hypocalcemia in Cows.

1.在试验一中，将1，25(OH)_2D_3[1，25(OH)_2D_3]注射于妊娠晚期奶牛产前12-48小时，观察其预防产妇低血钙症的效果。12头荷斯坦奶牛，至少第二胎，被分成两组。其中7头奶牛给予1μg/kg的1，25(OH)_2D_3乙醇溶液(1，25(OH)_2D_3组)，另外5头奶牛仅给予乙醇(对照组)。所有奶牛在给药后12-48小时产犊。1，25(OH)2D3组产前1d至产后0.5d血浆1，25(OH)2D3浓度显著高于对照组。结论：1.1，25(OH)_2D_3组在分娩前0.5天至产后2天血浆钙和IP水平一直处于较高水平，并显著高于对照组。结论：1，1，25(OH)_2D_3组在产犊前1~2天肌肉注射1，25(OH)_2D_3对产后低血钙症有预防作用。第二项研究的目的是调查乳房热的发生与骨代谢之间的关系。为了观察骨代谢的变化及其与乳房热发生发展的关系，对83头奶牛各哺乳期的血清抗酒石酸酸性磷酸酶(TRAP)活性进行了测定，证实了血清TRAP活性可用于评价奶牛的骨代谢。在牛奶热频繁的养殖场发现TRAP活性低，认为奶热的发生与骨代谢不活跃有关。认为血清TRAP活性测定可用于预防乳热。

1. In the first study, 1,25-dihydroxyvitamin D_3 [1,25(OH)_2D_3] was injected into late-pregnant cows 12-48 hours prepartum to evaluate the effect of 1,25(OH)_2D_3 for prevention of parturient hypocalcemia. Twelve Holstein cows, at least second parity, were assigned to two groups. Seven cows received 1 μg/kg of 1,25(OH)_2D_3 (1,25(OH)_2D_3 group) in ethanol, and the other five received only ethanol (control group). All cows calved 12-48 hours after administration. Plasma 1,25(OH)_2D_3 concentration in 1,25(OH)_2D_3 group was significantly higher 1 day pre- to 0.5 day postpartum than in control group. Plasma Ca and iP levels in 1,25(OH)_2D_3 group kept high near parturition, and were significantly higher than those in control group from 0.5 day before parturition to 2 days after parturition.In conclusion, it was considered that the intramuscular injection of 1,25(OH)2D3 before 1-2 day(s) of calving had prophylactic effect for parturient hypocalcemia.2. The aim of the second study was to investigate association between occurrence of milk fever and bone metabolism. To observe changes in bone metabolism and associations between it and the development of milk fever, we investigated serum tartrate-resistant acid phosphatase (TRAP) activity at each lactating stage n 83 cows.In this study, it was confirmed utilization of Trap activity in serum for evaluation of bone metabolism in cow. Occurrence of milk fever thought to be related with inactive bone metabolism from the finding of low TRAP activity in milk fever frequent farm. It was thought that measuring of serum TRAP activity was applied to prevent milk fever.