Densities of Ruminal Protozoa of Sheep Established Under Different Dietary Conditions

Faunal and some floral studies were made on the rumen of sheep under different dietary conditions.The density of rumen protozoa in animals fed hay plus concentrate was generally larger than that in animals fed hay.Density differences between the two dietary conditions were specific with respect to the kind of protozoa.Numbers of Dasytrieha ruminantium were unaffected by the two dietary conditions, and those of species belonging to Entodinium decreased moderately in one species and greatly in three species when aninmls were fed hay.With respect to higher oligotrichs, when Polyplastro~ multivesiculatum existed, it showed an intermediate mode between Dasytricha and Entodinium.Another three co-existing higher oligotrichs in other animMs, Eudiplodinium maggi, Epidinium ecaudatum f. caudatun b and Diplodinium dentatum~ showed diverse responses to the dietary change.These results and another observation which was seen in an animal fed hay are discussed with regard to known nutritional requirements of each species.It is suggested that four species belonging to Entodinium, the genus hitherto not dealt with specifically, have different feeding habits.Eaxlier reports that ruminants can grow apparently healthy without ruminal protozoa, seemed to invahdate an active role of protozoa in rumen fermentation.Recent experiments based on careful choice of experimental conditions, however, indicate that there are noticeable differences in animal growth and in chemical components in the runlen between faunated and defaunated animals (1, 5, 11).Thus, the role of ruminal protozoa again beans to attract attention.Feeding habits and enzymatic activities toward several carbohydrates were analyzed with ~eceived for publication August 5, 1968.