[The effect of parenteral administration of 25-hydroxycholecalciferol and 1 alpha-hydroxycholecalciferol on the mineral concentrations in the blood of cows in late pregnancy]. / Zur Wirkung von parenteral appliziertem 25-Hydroxycholecalciferol und 1 alpha-Hydroxy-cholecalciferol auf die Mineralstoffkonzentrationen im Blutplasma von hochträchtigen Kühen.

The effect of 1 - 3 intramuscular injections of the vitamin D3 metabolite 25-OHD3, synthetic 1 alpha-OHD3, and a combination of both on the plasma concentrations of calcium (Ca), inorganic phosphate (P(i)) and magnesium (Mg) was tested in 67 older dry dairy cows. Administering 4,0 mg 25-OHD3 reduced Ca and P(i) for some time while Mg blood levels remained constant. Injecting 210 micrograms 1 alpha-OHD3 plus 2.0 mg 25-OHD3 only brought a marked increase in P(i) concentrations, whereas 420 micrograms 1 alpha-OHD3 plus 4.0 mg 25-OHD3, and 350 micrograms 1 alpha-OHD3 alone significantly raised Ca and P(i) levels beginning on the 2nd day after injection and lasting for at least 6 days. These higher levels can be maintained by repeated injections. Another effect of injecting 1 alpha-OHD3 was to depress Mg blood levels, and a negative effect on the Ca and vitamin D3 metabolism is suggested which may cause hypocalcaemia when the effect of 1 alpha-OHD3 subsides. Metastatic calcifications of soft tissues were observed in some 1 alpha-OHD3-treated cows.

[Does the administration of derivatives of vitamin D to dairy cows in late pregnancy for the prevention of parturient paresis affect the maternal-fetal mineral metabolism?]. / Hat die Verabreichung von Derivaten des Vitamin D an hochträchtige Milchkühe zur Prophylaxe der Gebärparese Auswirkungen auf den maternal-fetalen Mineralstoff-wechsel?

Intramuscular injection of 1 alpha-hydroxyvitamin D3 (with or without 25-hydroxyvitamin D3) to highly pregnant dairy cows caused a significant increase of ionized calcium in blood and of total calcium and inorganic phosphate with a concomitant decrease of magnesium in blood plasma 3,5 +/- 1,9 days later (resp. 12-48 h a.p.). This brought about a higher Ca level at parturition preventing parturient paresis. The changes of maternal mineral and vitamin D status had no effect on the mineral concentrations of blood in newborn calves. However, the increase in calcium and phosphate concentrations in maternal blood after injection was accompanied by an increase of the minerals in the amniotic fluid reflecting their strong reciprocal exchange. On the other hand, the composition of allantoic fluid showed no significant changes. Therefore, analysis of both fetal fluids does not refer to disorders of fetal mineral metabolism. As a consequence, there seems to be no potential risk of intoxication after a prepartal injection of the substances to the mother for their offspring.

[The suitability of 1-alpha-hydroxycholecalciferol for the prevention of recurrent parturient paresis in dairy cows]. / Untersuchungen über die Eignung von 1-alpha-Hydroxycolecalciferol zur Prophylaxe von Gebärpareserezidiven der Milchkuh.

Sixty-four cows with parturient paresis were given a standard treatment of 500 ml calcium gluconate (10.7 g Ca++) infusion solution. Twelve of these cows (experimental group = EG 1) additionally received 420 micrograms 1-alpha-hydroxycholecalciferol (1-alpha-OHD3) with 4 mg 25-hydroxycholecalciferol (25-OHD3) by the intramuscular route. A further 9 and 10 cows were given 210 micrograms 1-alpha-OHD3 and 2 mg 25-OHD3 (EG 3) with the calcium infusion, while 10 cows received either 420 micrograms 1-alpha-OHD3 (EG 4) or 210 micrograms 1-alpha-OHD3 (EG 5). Twenty-three cows (EG 2 and 4) which were given a calcium infusion alone acted as controls. The incidence of recurrence could not be reduced by the administration of Vitamin D3 metabolites concurrently with a calcium infusion, although calcium and phosphorus levels were higher between 24 and 48 hours after calcium infusion alone. The combination of 1-alpha-OHD3/25-OHD3 at the higher dosage resulted in the highest calcium levels.

[Ionized calcium and total calcium in the blood of cattle, sheep, swine and horses of different ages, reproductive stages and uses]. / Ionisiertes Calcium und Gesamtcalcium im Blut von Rindern, Schafen, Schweinen und Pferden verschiedener Alters- und Reproduktionsstadien und Nutzungsrichtungen.

Concentrations of ionized calcium (Cai) in blood and of total calcium (Ca(t)) in serum were determined in 99 cattle, 58 sheep, 74 pigs and 59 horses of different age groups and reproductive periods as well as kinds of use of the animals. The values of Cai in blood in the groups taken into account for comparison of species decreased significantly in the order dairy cows < ewes < sows < horses. In cattle and pigs, there were significant differences in the Cai-level, according to age with the youngest animals having the highest values. In cows from the fourth lactation onward, one day post partum (p.p.) the smallest concentrations were measured, differing significantly from animals in other reproductive periods. In ewes, the lowest values were estimated one week before parturition. The level of Cai in blood of sows decreased between day one and 6 weeks p.p. significantly. No significant differences could be demonstrated between the different groups of horses. With regard to the concentrations of total Ca, differences between the groups were not so clear as with Cai.

The effects of intramuscularly administered vitamin D3, 25- and 1 alpha-hydroxycholecalciferol in cows on plasma mineral content, plasma 25-hydroxycholecalciferol and on mineral deposits in soft tissues.

The investigations were carried out to evaluate potential side effects of a prophylaxis with high doses of vitamin D3 and vitamin D metabolites in parturient paresis. For this reason, 10(7) IU vitamin D3 (= 250 mg), 4 mg 25-OHD3 or 420 micrograms 1 alpha-OHD3 were applied to non-gravid dairy cows at the end of lactation. The application was repeated 3 times at one week intervals and the changes of the mineral concentration and 25-OHD were measured in the plasma. The pathomorphological changes in the cardio-vascular system and other organs were examined macro- and microscopically. The application of vitamin D3 and 25-OHD3 led to an immediate and continuous increase of the 25-OHD concentration in the plasma. On the other hand, administration of 1 alpha-OHD3 resulted in a decrease of the 25-OHD level. After the application of vitamin D3 and 1 alpha-OHD3, the Ca and Pi concentration increased significantly. After 25-OHD3, the Ca concentration decreased below the initial level in the second week. The administration of all 3 compounds led to a significant decrease of the Mg concentration after the first injection. The administration of vitamin D3 and 1 alpha-OHD3 resulted in a significantly more pronounced calcinosis of inner organs while after the application of 25-OHD3 only occasionally calcium deposits were observed in the vascular system.