In vivomeasurements of the production rates of bacteria in the rumen

Summary The production rates of bacteria have been measured in the rumen of zebu calves and buffalo calves. The animals were fed green oat continuously at 2 h intervals. [ 35 S]sodium sulphate was fed to the animals for 5 days at 2 h intervals by mixing in the feed. On the sixth day the radioactive feed was stopped and replaced by non-radioactive feed. The decline in the specific radioactivity of bacterial cells in the rumen as a function of time was taken for calculating t /2. Simultaneously rumen volume was determined and pool size of bacterial cells was calculated in the rumen. A mathematical equation was applied to calculate the production rates of bacteria. The production rates of bacteria, on average, were 100·5 and 72·3 mg/min for buffalo calves and zebu calves, respectively.