| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal Sciences, Faculty of Agricultural, Food and Environmental, Quality Sciences, The Hebrew University of Jerusalem, Israel
2 Department of Animal Sciences, University of Illinois, Urbana 61801
3 Institute of Animal Sciences, Volcani Center, ARO, Israel
4 Animal Sciences Department, Cukurova University, Turkey
We partitioned the flow of amino acids (AA) to the abomasum among rumen undegradable protein (RUP) and bacterial, protozoal, and endogenous fractions using four Holstein cows in midlactation that were equipped with ruminal and abomasal cannulas. A 2 x 2 factorial design with four diets, combinations of high or low ruminally degradable organic matter, and rumen degradable protein, was employed. Crude protein (CP) and AA contents of ruminal bacteria and protozoa and abomasal digesta were determined. Equations for the source compositions and in vivo flows of CP and 16 AA were then solved simultaneously with a linear program to estimate the contribution of RUP, bacterial, protozoal, and endogenous CP to AA flows. The flows of RUP and bacterial AA were not affected by diet. Low dietary RDP increased the flow of protozoal AA to the abomasum, but the ruminally degradable organic matter content of the diet did not affect protozoal AA flow. Across diets, RUP, bacterial, protozoal, and endogenous fractions provided 55, 33, 11, and <1% of the CP, and 62, 26, 12, and <1% of the AA that reached the abomasum. The linear program was a useful tool for partitioning AA that flows to the abomasum. The technique may also allow dietary effects on ruminal microbes and the AA profile of protein flowing to the duodenum to be better understood and perhaps manipulated.
Key Words: bacteria • protozoa • AA profile
Submitted on January 7, 2000
Accepted on April 5, 2000
This article has been cited by other articles:
|
|
 |
|
  H. Lapierre, D. Pacheco, R. Berthiaume, D. R. Ouellet, C. G. Schwab, P. Dubreuil, G. Holtrop, and G. E. Lobley What is the True Supply of Amino Acids for a Dairy Cow? J Dairy Sci, March 1, 2006; 89(e_suppl_1): E1 - E14. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Reynal, G. A. Broderick, and C. Bearzi Comparison of Four Markers for Quantifying Microbial Protein Flow from the Rumen of Lactating Dairy Cows J Dairy Sci, November 1, 2005; 88(11): 4065 - 4082. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. J. Scholljegerdes, T. R. Weston, P. A. Ludden, and B. W. Hess Supplementing a ruminally undegradable protein supplement to maintain essential amino acid supply to the small intestine when forage intake is restricted in beef cattle J Anim Sci, September 1, 2005; 83(9): 2151 - 2161. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Sylvester, S. K. R. Karnati, Z. Yu, C. J. Newbold, and J. L. Firkins Evaluation of a Real-Time PCR Assay Quantifying the Ruminal Pool Size and Duodenal Flow of Protozoal Nitrogen J Dairy Sci, June 1, 2005; 88(6): 2083 - 2095. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bach, S. Calsamiglia, and M. D. Stern Nitrogen Metabolism in the Rumen J Dairy Sci, May 1, 2005; 88(e_suppl_1): E9 - E21. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Reynal, G. A. Broderick, S. Ahvenjarvi, and P. Huhtanen Effect of Feeding Protein Supplements of Differing Degradability on Omasal Flow of Microbial and Undegraded Protein J Dairy Sci, April 1, 2003; 86(4): 1292 - 1305. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
