ISOCUPRESSIC ACID, AN ABORTIFACIENT COMPONENT OF CUPRESSUS-MACROCARPA

Anecdotal reports suggest that abortion occurs in New Zealand cattle a fter ingestion of macrocarpa (Cupressus macrocarpa). The clinical sign s observed are similar to those seen in abortions caused by ponderosa pine (Pinus ponderosa Laws). Isocupressic acid has been identified as an abortifacient component of the needles of ponderosa pine. Macrocarp a collected from the Palmerston North area contained 0.89% and 1.24% i socupressic acid, compared to 1.70% isocupressic acid in Ponderosa pin e needles from Oregon in the United States as analysed by the USDA-ARS Poisonous Plant Research Laboratory. These findings support observati ons that macrocarpa causes abortion in late gestation cattle in New Ze aland and suggest the causal agent is probably isocupressic acid.