Glucose Metabolism and Milk Yield of Cows Infused Abomasally or Ruminally with Starch

¹ Department of Animal Sciences, University of Maryland, College Park 20742
² Nutrient Conservation and Metabolism Laboratory, Livestock and Poultry Sciences Institute, USDA, Agricultural Research Service, Beltsville, MD 20705
³ Department of Animal Science, North Carolina State University, Raleigh 27614

The effect of ruminal or abomasal starch infusion on milk yield and glucose metabolism of early lactation cows was measured. Four cows were continuously infused in the rumen or abomasum with partially hydrolyzed starch (1500 g/d) or were not infused (control) for three 14-d periods during wk 4 to 12 postpartum. Milk yield averaged over 40 kg/d throughout the experiment. Milk and milk lactose yields tended to increase when starch was infused and DMI was decreased, regardless of the site of infusion. Starch infusion increased mean insulin concentration and tended to decrease the concentration of serum nonesterified fatty acids. Ruminal starch infusion did not affect glucose irreversible loss rate but tended to increase glucagon concentration and decrease glucose oxidation. The increased milk yield that occurred when starch was infused ruminally relative to the milk yield of control cows could be a result of increased microbial protein supply or increased energy availability. Compared with ruminal starch infusion, abomasal starch infusion tended to increase the irreversible loss rate of glucose and to increase glucose oxidation. Abomasal infusion tended to increase plasma insulin concentration and to decrease the nonesterified fatty acid concentration relative to ruminal infusion. Infusion of starch abomasally resulted in increases of most uses of glucose, including milk lactose production, glucose oxidation, and the possible storage of glucose as body fat, which indicates that the early lactation dairy cow has a greater capacity for glucose metabolism than is provided by voluntary feed intake of average diets, but that not all available glucose is partitioned to the mammary gland. These data should be useful in testing current concepts and equations in nutritional and metabolic models of dairy cattle.

Key Words: dairy cows • starch infusion • glucose metabolism

Submitted on February 10, 1998
Accepted on August 14, 1998

This article has been cited by other articles:

				H. M. Hammon, C. C. Metges, P. Junghans, F. Becker, O. Bellmann, F. Schneider, G. Nurnberg, P. Dubreuil, and H. Lapierre Metabolic Changes and Net Portal Flux in Dairy Cows Fed a Ration Containing Rumen-Protected Fat as Compared to a Control Diet J Dairy Sci, January 1, 2008; 91(1): 208 - 217. [Abstract] [Full Text] [PDF]

				A. Boudon, P. Faverdin, R. Delagarde, P. Lamberton, and J. L. Peyraud Effects of Rumen or Duodenal Glucose Infusions on Intake in Dairy Cows Fed Fresh Perennial Ryegrass Indoors J Dairy Sci, September 1, 2007; 90(9): 4397 - 4410. [Abstract] [Full Text] [PDF]

				T. F. Gressley, S. M. Reynal, J. J. O. Colmenero, G. A. Broderick, and L. E. Armentano Technical note: development of a tool to insert abomasal infusion lines into dairy cows. J Dairy Sci, October 1, 2006; 89(10): 3965 - 3967. [Abstract] [Full Text] [PDF]

				G. B. Huntington, D. L. Harmon, and C. J. Richards Sites, rates, and limits of starch digestion and glucose metabolism in growing cattle J Anim Sci, April 1, 2006; 84(13_suppl): E14 - E. [Abstract] [Full Text] [PDF]

				C. C. Taylor and M. S. Allen Corn Grain Endosperm Type and Brown Midrib 3 Corn Silage: Site of Digestion and Ruminal Digestion Kinetics in Lactating Cows J Dairy Sci, April 1, 2005; 88(4): 1413 - 1424. [Abstract] [Full Text] [PDF]

				S. Lemosquet, S. Rigout, A. Bach, H. Rulquin, and J. W. Blum Glucose Metabolism in Lactating Cows in Response to Isoenergetic Infusions of Propionic Acid or Duodenal Glucose J Dairy Sci, June 1, 2004; 87(6): 1767 - 1777. [Abstract] [Full Text] [PDF]

				K. C. Swanson, J. A. Benson, J. C. Matthews, and D. L. Harmon Pancreatic exocrine secretion and plasma concentration of some gastrointestinal hormones in response to abomasal infusion of starch hydrolyzate and/or casein J Anim Sci, June 1, 2004; 82(6): 1781 - 1787. [Abstract] [Full Text] [PDF]