Abstract
A simple technique for measuring the rate of fermentation of rumen microorganisms is described. It allows quick preparation and handling of the rumen sample immediately after collection. The average rate of fermentation of rumen samples collected from a lactating cow fed on alfalfa hay and concentrate in the ratio of 2:1 was very similar to the rate obtained by other methods. On the assumption that when substrate is in excess, the fermentation rate is proportional to the total microbial cells, the method was used to estimate the net growth of rumen microorganisms. The maximal fermentation rate of subsamples, taken at the beginning and after 1 hr of incubation of a sample, was measured. The results indicate a net average growth of 8% per hr, or 192% per day, in approximate agreement with rumen turnover time. The highest net growth does not necessarily coincide with the highest gas-production rate in the rumen, in part because the bicarbonate concentration in the rumen contents varies. In a cow fed on hay and concentrate, the net growth was lowest before feeding and immediately after feeding.
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Selected References
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- BAUCHOP T., ELSDEN S. R. The growth of micro-organisms in relation to their energy supply. J Gen Microbiol. 1960 Dec;23:457–469. doi: 10.1099/00221287-23-3-457. [DOI] [PubMed] [Google Scholar]
- CARROLL E. J., HUNGATE R. E. The magnitude of the microbial fermentation in the bovine rumen. Appl Microbiol. 1954 Jul;2(4):205–214. doi: 10.1128/am.2.4.205-214.1954. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CASTLE E. J. The rate of passage of foodstuffs through the alimentary tract of the goat. I. Studies on adult animals fed on hay and concentrates. Br J Nutr. 1956;10(1):15–23. doi: 10.1079/bjn19560005. [DOI] [PubMed] [Google Scholar]
- HUNGATE R. E., FLETCHER D. W., DOUGHERTY R. W., BARRENTINE B. F. Microbial activity in the bovine rumen: its measurement and relation to bloat. Appl Microbiol. 1955 May;3(3):161–173. doi: 10.1128/am.3.3.161-173.1955. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HUNGATE R. E., MAH R. A., SIMESEN M. Rates of production of individual volatile fatty acids in the rumen of lactating cows. Appl Microbiol. 1961 Nov;9:554–561. doi: 10.1128/am.9.6.554-561.1961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WELLER R. A., GRAY F. V., PILGRIM A. F. The conversion of plant nitrogen to microbial nitrogen in the rumen of the sheep. Br J Nutr. 1958;12(4):421–429. doi: 10.1079/bjn19580056. [DOI] [PubMed] [Google Scholar]