Effect of Monensin capsules on blood metabolites near calving in twin-pregnant and single-pregnant beef cows

摘要

The aim of this study was to test the hypothesis that Ruraensin capsules administered during late pregnancy would have equally beneficial effects in single- and twin-pregnant beef cows, on circulating levels of beta-hydroxy butyrate (BOH), magnesium (Mg) and glucose. Forty cows, half of which were twin pregnant, were treated with either a single Rumensin capsule from a mean of 66 d prior to calving, or remained asuntreatedcontrols.Plasmasamples were taken ond 66, 38, 23, 13 and 5 prior to calving. Rumensin lowered BOH concentration by the second sampling time (0.53 vs. 0.76 mmol/1, P<0.01) and maintained this concentration until calving. Rumensin was without effect on Mg or glucose concentrations. The effects of Rumensin were additive to those of pregnancy status (twin vs. single) for all three metabolites thus confirming our hypothesis. Rumensin may therefore be useful in the late pregnancy management of twin pregnant cows.