The composition of ruminal and abomasal fluid from catheterised fetal sheep during the last 50 days of pregnancy.

A catheterisation technique for obtaining fluid samples from the rumen and abomasum of fetal sheep between 90 and 140 days gestation is described. The osmolalities and sodium concentrations were higher and the potassium concentrations lower in the ruminal and abomasal fluids than in amniotic fluid, and the mean pH of the amniotic, ruminal and abomasal fluids was 7.0.