The effect of certain feedingstuffs on rumen ciliate protozoain vitro

Abstract

SUMMARYMeadow hay and mixed food containing 13·3 or 26·9% of concentrates were used for culturing ciliates taken from the rumen of water buffalo. The culture medium was the sterilized rumen fluid or a solution of mineral salts. The cultures were mixed every 24h and one-half of the contents of each culture flask was transferred to an equal volume of fresh medium containing the appropriate food.Anoplodinium denticulatumand seven species ofEntodiniumwere the only protozoa which survived until the end of the experiment, but to maintain them on food containing 26·9% of concentrates an alkaline or neutral medium was required. Using rumen fluid and mineral medium the total number of protozoa was on average, respectively: 2·7 x 103and 2·2 x 103/ml in cultures on hay only; 9·4 x 103and 17·5 x 103/ml in cultures on food containing 26·9% of concentrates; and 14·0 x 103and 17·;8 x 103/ml in cultures on food containing 13·3% of concentrates.Entodiniumformed 66·6 and 72·5%; 95·5 and 91·8%; and 96·1 and 97·7% of the total counts. In cultures on hay alone there were 33·4 and 27·5% ofAnoplodinium denticulatum, while they formed only 4·5 and 8·2% and 3·9 and 2·3% in cultures on food containing 26·9 and 13·3% of concentrates respectively.The relation between number of ciliates and composition of food only partly agreed with the relation found previously under natural conditions. Changes in pH of the medium would appear to be the chief cause.