QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Heitmann, R. N. Articles by Sensenig, S. C. Search for Related Content PubMed PubMed Citation Articles by Heitmann, R. N. Articles by Sensenig, S. C.

Hepatic Ketogenesis and Peripheral Ketone Body Utilization in the Ruminant¹

Department of Animal Science, University of Tennessee, Knoxville, TN 37901

Hepatic and alimentary ketogenesis occur at similar rates in fed, nonpregnant, nonlactating goats, sheep and dairy cows. Alimentary ketogenesis begins to diminish within 24 h after fasting but compensatory increases in hepatic ketogenesis maintain total splanchnic release and, therefore, no change in circulating concentrations of ketone bodies is observed. By the third day of fast the gut is utilizing acetoacetate and ß-hydroxybutyrate and alimentary ketogenesis has ceased. Hepatic ketogenesis of both ketone bodies accelerates rapidly due to portal-drained visceral and hindquarter lipolysis and subsequent hepatic fatty acid uptake and total circulating concentrations are doubled. During pregnancy and lactation in sheep and cows alimentary ketogenesis is maintained as long as digestible organic matter intake is constant. Hepatic and total splanchnic release of ß-hydroxybutyrate increases in late gestation and early lactation. Again, this is due to increased portal-drained visceral and hindquarter free fatty acid release and hepatic free fatty acid uptake. Hindquarter uptake of both ketones during late gestation is similar to the ratio observed in nonpregnant fed sheep but the percentage of utilization decreases, perhaps reflecting partitioning to uteroplacental tissues. Hindquarter uptake of both ketone bodies in sheep increases in early lactation due to increased circulating concentrations because extraction ratios are similar to those of fed animals. Ketosis during pregnancy in sheep and lactation in cows may be prevented by ß-hydroxybutyrate stimulation of pancreatic insulin production. However, an insulin-independent intrahepatic mechanism apparently occurs in sheep. Such a mechanism may allow for the regulation of hepatic ketogenesis without increases in pancreatic insulin production and could be most important in lactating dairy cows, because low insulin concentrations are positively correlated to milk production. It has yet to be determined whether the insulin-independent mechanism is present in high producing dairy cows.

KEY WORDS: • acetoacetate • ß-hydroxybutyrate • ketogenesis • ruminants

¹ Presented as part of the symposium, "Energy Metabolism in Live-stock Species," at the 5th Joint Meeting of the American Institute of Nutrition, the American Society for Clinical Nutrition and the Canadian Society for Nutritional Sciences, Davis, CA, July 1986.

Manuscript received 18 September 1986. Revision accepted 6 January 1987.

This article has been cited by other articles:

				J. Guo, R. R. Peters, and R. A. Kohn Modeling Nutrient Fluxes and Plasma Ketone Bodies in Periparturient Cows J Dairy Sci, November 1, 2008; 91(11): 4282 - 4292. [Abstract] [Full Text] [PDF]

				J. Guo, R. R. Peters, and R. A. Kohn Effect of a Transition Diet on Production Performance and Metabolism in Periparturient Dairy Cows J Dairy Sci, November 1, 2007; 90(11): 5247 - 5258. [Abstract] [Full Text] [PDF]

				J. L. Klotz and R. N. Heitmann Changes in Net Portal Nutrient Flux in Response to Weaning Transition and Ionophore Supplementation in Dairy Calves J Dairy Sci, March 1, 2007; 90(3): 1326 - 1339. [Abstract] [Full Text] [PDF]

				D. B. Carlson, N. B. Litherland, H. M. Dann, J. C. Woodworth, and J. K. Drackley Metabolic Effects of Abomasal L-Carnitine Infusion and Feed Restriction in Lactating Holstein Cows J Dairy Sci, December 1, 2006; 89(12): 4819 - 4834. [Abstract] [Full Text] [PDF]

				J. M. DeFrain, A. R. Hippen, K. F. Kalscheur, and D. J. Schingoethe Feeding Lactose to Increase Ruminal Butyrate and the Metabolic Status of Transition Dairy Cows J Dairy Sci, January 1, 2006; 89(1): 267 - 276. [Abstract] [Full Text] [PDF]