Occurrence of Protozoa in the Bovine Stomach

Abstract

The digestive tracts of Jersey calves were devoid of protozoa at birth. Examination of samples taken freshly from the stomach compartments and ileums of 12 Jersey calves and a cow from the station herd showed 18 spp. of 8 genera of protozoa. Protozoa were teeming in the rumino-reticular cavity, some living ones persisted in the omasum, nearly all in the abomasum were non-motile (dead?) and none was seen intact in the ileum. This disappearance suggests that their main activity took place in the first-named compartment and that, after being rendered non-motile, they were digested by the host. Green inclusions (chlorophyll) were observed in Entodinium bursa. Calves appeared to acquire more spp. of protozoa as they became older.