The Effect of Amino Nitrogen on the Energetics of Ruminal Bacteria and Its Impact on Energy Spilling

¹ Department of Animal Science, Cornell University, Ithaca, NY 14853
² Section of Microbiology, Cornell University and Agricultural Research Service, Ithaca, NY 14853

The predominant ruminal bacteria that were obtained from a 10⁸ dilution of ruminal fluid could be maintained as a mixed population for long periods as long as the bacteria were provided with a complex mixture of carbohydrates. Growth of predominant ruminal bacteria in carbohydrate-limited, ammonia-excess, continuous cultures (0.07/h) had a low requirement for maintenance energy, but the non-growth energy dissipation of ammonia-limited, carbohydrate-excess, predominant ruminal bacteria was approximately 10-fold higher (0.96 vs. 0.09 mg of hexose equivalent/mg of protein per h, respectively). Mathematical derivations indicated that this additional nongrowth energy dissipation could be accommodated by an energy spilling function that was independent of the growth rate. Peptides and amino acids had little impact on the yield of carbohydrate-limited, ammonia-excess, continuous cultures (0.07/h), but amino N greatly increased the growth rate and yield of excess-energy batch cultures. The change in growth rate and yield that was dependent on amino N indicated that the energy-excess batch cultures had the same capacity to spill energy as did the ammonia-limited, carbohydrate-excess, predominant ruminal bacteria (0.80 vs. 0.86 mg of hexose equivalent/mg of protein per h, respectively). When the energy-excess batch cultures were provided with amino N, the growth rate increased, the difference in anabolic and catabolic rates was smaller, and less energy was spilled.

Key Words: ruminal bacteria • peptides • amino acids • energy

Submitted on May 22, 1995
Accepted on January 9, 1996

This article has been cited by other articles:

				M. B. Hall and P. J. Weimer Sucrose concentration alters fermentation kinetics, products, and carbon fates during in vitro fermentation with mixed ruminal microbes J Anim Sci, June 1, 2007; 85(6): 1467 - 1478. [Abstract] [Full Text] [PDF]

				C. Lanzas, L. O. Tedeschi, S. Seo, and D. G. Fox Evaluation of Protein Fractionation Systems Used in Formulating Rations for Dairy Cattle J Dairy Sci, January 1, 2007; 90(1): 507 - 521. [Abstract] [Full Text] [PDF]

				A. Rotger, A. Ferret, S. Calsamiglia, and X. Manteca Effects of nonstructural carbohydrates and protein sources on intake, apparent total tract digestibility, and ruminal metabolism in vivo and in vitro with high-concentrate beef cattle diets J Anim Sci, May 1, 2006; 84(5): 1188 - 1196. [Abstract] [Full Text] [PDF]

				I. J. Lean, T. K. M. Webster, W. Hoover, W. Chalupa, C. J. Sniffen, E. Evans, E. Block, and A. R. Rabiee Effects of BioChlor and Fermenten on Microbial Protein Synthesis in Continuous Culture Fermenters J Dairy Sci, July 1, 2005; 88(7): 2524 - 2536. [Abstract] [Full Text] [PDF]

				H. Kajikawa, M. Mitsumori, K. Tajima, and M. Kurihara Short Communication: Amino Acids Antagonistic to the Amino Acids Inhibitory for Growth Rate of Mixed Ruminal Bacteria J Dairy Sci, July 1, 2005; 88(7): 2601 - 2603. [Abstract] [Full Text] [PDF]

				C. C. Taylor and M. S. Allen Corn Grain Endosperm Type and Brown Midrib 3 Corn Silage: Ruminal Fermentation and N Partitioning in Lactating Cows J Dairy Sci, April 1, 2005; 88(4): 1434 - 1442. [Abstract] [Full Text] [PDF]

				J. A. Voelker and M. S. Allen Pelleted Beet Pulp Substituted for High-Moisture Corn: 3. Effects on Ruminal Fermentation, pH, and Microbial Protein Efficiency in Lactating Dairy Cows J Dairy Sci, November 1, 2003; 86(11): 3562 - 3570. [Abstract] [Full Text] [PDF]

				E. R. Otto, M. Yokoyama, S. Hengemuehle, R. D. von Bermuth, T. van Kempen, and N. L. Trottier Ammonia, volatile fatty acids, phenolics, and odor offensiveness in manure from growing pigs fed diets reduced in protein concentration J Anim Sci, July 1, 2003; 81(7): 1754 - 1763. [Abstract] [Full Text] [PDF]

				M. Oba and M. S. Allen Effects of Diet Fermentability on Efficiency of Microbial Nitrogen Production in Lactating Dairy Cows J Dairy Sci, January 1, 2003; 86(1): 195 - 207. [Abstract] [Full Text] [PDF]

				R. Ruiz, L. O. Tedeschi, J. C. Marini, D. G. Fox, A. N. Pell, G. Jarvis, and J. B Russell The Effect of a Ruminal Nitrogen (N) Deficiency in Dairy Cows: Evaluation of the Cornell Net Carbohydrate and Protein System Ruminal N Deficiency Adjustment J Dairy Sci, November 1, 2002; 85(11): 2986 - 2999. [Abstract] [Full Text] [PDF]

				H. Kajikawa, M. Mitsumori, and S. Ohmomo Stimulatory and Inhibitory Effects of Protein Amino Acids on Growth Rate and Efficiency of Mixed Ruminal Bacteria J Dairy Sci, August 1, 2002; 85(8): 2015 - 2022. [Abstract] [Full Text] [PDF]

				B. Stefanon, V. Volpe, S. Moscardini, and L. Gruber Using Artificial Neural Networks to Model the Urinary Excretion of Total and Purine Derivative Nitrogen Fractions in Cows J. Nutr., December 1, 2001; 131(12): 3307 - 3315. [Abstract] [Full Text] [PDF]