Effect of asynchronous nitrogen and energy supply on growth of ruminal bacteria in batch culture.

J. R. Newbold*, S. R. Rust

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

47 Citations (Scopus)


The effects of an asynchronous supply of fixed amounts of N and carbohydrate on bacterial growth were measured in two batch culture experiments. In Exp. 1, aqueous glucose and urea solutions were added at hourly intervals to culture flasks containing strained ruminal liquor and phosphate/bicarbonate buffer. The ratio of urea N to glucose was either constant (Synchrony, 26 mg of N/g of glucose) or increased exponentially over time (Asynchrony, .013 to 48,900 mg of N/g of glucose). After 12 h, identical quantities of glucose and urea had been added in both treatments. Bacterial population size (estimated from optical density) was greater (P less than .001) from 5 to 8 h of incubation for Synchrony than for Asynchrony, but after 12 h there was no difference (P greater than .1) between treatments. In Exp. 2, large (1 to 1.5 mm) and small (less than .5 mm) corn particles were used as slowly and rapidly degraded energy sources, with soybean meal (1 to 1.5 mm) and a papaic digest of soybean meal as sources of slowly and rapidly degraded N. At incubation times, when the ratio between total starch and N degraded was equal between treatments, bacterial population size was unaffected by the relative rate of N and OM supply. In both experiments, bacterial growth recovered quickly from transient restriction caused by deficits of N.

Original languageEnglish
Pages (from-to)538-546
Number of pages9
JournalJournal of Animal Science
Issue number2
Publication statusPrint publication - Feb 1992
Externally publishedYes

Bibliographical note

Copyright © 1992 by American Society of Animal Science


Dive into the research topics of 'Effect of asynchronous nitrogen and energy supply on growth of ruminal bacteria in batch culture.'. Together they form a unique fingerprint.

Cite this