Diurnal variation in ciliate protozoa in the rumen of black buck (Antilope cervicapra) fed green forage

The protozoa in the rumen of a black buck were a B‐type population with numbers varying between 0·31 and 0·61 times 106cells/ml rumen liquor, when the animal was fed either vegetative green oat or third cut berseem. The total protozoa, total holotrichs, Dasytricha, total spirotrichs and small spirotrichs were significantly higher (P < 0·01) on berseem feeding than those on oat feeding, while the numbers of Isotricha and large spirotrichs were unaffected by change of diet. Numerically the most important group of protozoa was small spirotrichs (74·4–75·6% of total population) which accounted for only 9·85–13·61% of protozoal cell mass in the rumen.