|
|
||||||||
Journal of Animal Science, Vol 70, Issue 5 1534-1542, Copyright © 1992 by American Society of Animal Science
JOURNAL ARTICLE |
X. B. Chen, Y. K. Chen, M. F. Franklin, E. R. Orskov and W. J. Shand
Rowett Research Institute, Bucksburn, Aberdeen, UK.
Urinary excretion of purine derivatives (PD) was used to estimate the microbial N (MN) supply to sheep in three experiments designed to examine the effects of DMI and BW on the efficiency of microbial N supply (EMNS) to the host animal. In Exp. 1, four sheep of about 45 kg BW were given 328, 656, 984, and 1313 g of DM/d of a hay/concentrate diet in a Latin square design. Excretion of PD per kilogram of digestible organic matter intake (DOMI) increased with intake, and EMNS increased from 12.0 to 28.3 g of MN/kg of OM digested in the rumen (DOMR). In Exp. 2, 19 sheep ranging from 22 to 73 kg BW were all offered 820 g of DM/d of the same diet as that fed in Exp. 1. Although DM digestibility was relatively constant, PD excretion varied from 4.5 to 13.5 mmol/d and EMNS from 8 to 36 g of MN/kg of DOMR, both inversely related to animal BW. In Exp. 3, five sheep of 48 to 57 kg BW were given a different diet at 702, 966, or 1,237 g of DM/d. Purine derivative excretion per kilogram of DOMI increased with the DMI:BW ratio. Calculated EMNS ranged from 23 to 35 g of MN/kg of DOMR. Pooled data from all experiments showed EMNS to be related to the DMI:BW ratio. It is suggested that the DMI:BW ratio defines the ruminal digesta passage rate and hence outflow of microbial protein. The results imply that the EMNS for a given diet is not constant, but changes with intake.
This article has been cited by other articles:
![]() |
D. R. Yanez Ruiz, A. I. Martin Garcia, A. Moumen, and E. Molina Alcaide Ruminal fermentation and degradation patterns, protozoa population and urinary purine derivatives excretion in goats and wethers fed diets based on olive leaves J Anim Sci, October 1, 2004; 82(10): 3006 - 3014. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. R. Yanez Ruiz, A. Moumen, A. I. Martin Garcia, and E. Molina Alcaide Ruminal fermentation and degradation patterns, protozoa population, and urinary purine derivatives excretion in goats and wethers fed diets based on two-stage olive cake: Effect of PEG supply J Anim Sci, July 1, 2004; 82(7): 2023 - 2032. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Richardson, R. G. Wilkinson, and L. A. Sinclair Synchrony of nutrient supply to the rumen and dietary energy source and their effects on the growth and metabolism of lambs J Anim Sci, May 1, 2003; 81(5): 1332 - 1347. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |