Changes of Acid-Base Variables in Dairy Cows with Chronically Implanted Fetal and Maternal Catheters during Late Gestation and Calving.

The objective of the present study was to evaluate the changes in maternal and fetal arterial acid-base variables withdrawn from catheterized dams and fetuses during the last days before and during calving. The average gestation length in nine cows with chronically catheterized fetuses was 285 ± 10 (SD) days. The arterial acid-base variables of a catheterized dam and fetus were very stable during late gestation.

Development of a surgical technique for long-term catheterisation of bovine fetuses.

The aim of this study was to further develop and extensively describe a surgical technique in order to realise long-term fetal blood sampling in the bovine species. Eleven Holstein-Friesian 6- to 8-month pregnant cows (4-10 years old) were used for this study. Gestational age on the day of surgery varied from approximately 180 days (n = 1) to 240 days (minimum: 232 days, maximum 252 days; n = 10).