|
|
||||||||
Department of Avian Science, University of California, Davis 95616
ABSTRACT
Slices from mammary glands from six lactating Holstein cows were incubated in Krebs-Ringer bicarbonate-based media in the presence of varying concentrations of acetate, glucose, and lactate. Conversions of acetate to carbon dioxide, fatty acids, citrate, glyceride-glycerol, and lactose were determined. Specific effects of betahydroxybutyrate and stearate availability also were evaluated. Utilization of acetate for all functions usually followed Michaelis-Menten kinetics with apparent affinities in the physiological concentration range of acetate. Availability of glucose had a large "permissive" effect on acetate to conversion to fatty acids. However, acetate metabolism was independent of the availability of lactate. Conversion of acetate to glyceride-glycerol was significant. This indicates the possibility of bidirectional glycolytic flux, which could limit glucose conversion to fatty acids.
Addition of stearate caused general increases of acetate metabolism. Conversion of acetate to fatty acids, carbon dioxide, and citrate was elevated in the absence of beta-hydroxybutyrate. The latter observation indicates beta-hydroxybutyrate may not be a required initiator of fatty acid synthesis in mammary tissue.
1 From Ph.D. dissertation of Neil E. Forsberg.
2 Department of Avian Science, Cornell University.
3 Ralston Purina Co., St. Louis, MO.
This article has been cited by other articles:
![]() |
N. G. Purdie, D. R. Trout, D. P. Poppi, and J. P. Cant Milk Synthetic Response of the Bovine Mammary Gland to an Increase in the Local Concentration of Amino Acids and Acetate J Dairy Sci, January 1, 2008; 91(1): 218 - 228. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. K. Drackley, S. S. Donkin, and C. K. Reynolds Major advances in fundamental dairy cattle nutrition. J Dairy Sci, April 1, 2006; 89(4): 1324 - 1336. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |