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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #66156
Title: ACIDOSIS AFFECTS INSULIN RESPONSE DURING GLUCOSE TOLERANCE TESTS IN JERSEY COWS

Author
item BIGNER, DORI - IA STATE UNIV., AMES, IA
item Goff, Jesse
item FAUST, MARJORIE - IA STATE UNIV., AMES, IA
item BURTON, JEANNE - FORMER USDA/ARS/MWA/NADC
item TYLER, HOWARD - IA STATE UNIV., AMES, IA
item Horst, Ronald

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: A severe increase in blood acidity is a complicating factor in many diseases. One such disease is ketosis, which affects high-producing dairy cows (4 to 7% of dairy cows), costing producers up to $60 million annually in treatment costs and lost productivity. This disease occurs when blood sugar concentration falls to very low levels as a result of blood sugar being utilized to make milk sugars and cream. The lack of blood sugar causes loss of proper nerve function; the cow is uncoordinated, refuses to eat, and milk production declines dramatically. The body tries to compensate by producing energy from fats rather than sugar and, in this process, acids begin to increase in the blood. In this study, we demonstrate that high levels of acid in the blood prevent the cow from releasing insulin; a hormone made in the pancreas that helps control blood sugar concentrations. Without insulin, the recovery of the cow from the disease is compromised. We have been able to demonstrate that if the cow is treated for the high blood acid condition, we can restore nearly normal insulin release from the pancreas. Our data suggest that the recovery of cows from ketosis would be enhanced if blood acids were first neutralized. If successfully adopted by veterinarians, the loss in productivity associated with ketosis could be greatly reduced.

Technical Abstract: The effect of metabolic alkalosis, corrected and uncorrected metabolic acidosis on insulin response to glucose tolerance tests, was determined in non-lactating, non-pregnant Jersey cows fed a diet high in cations to induce a state of metabolic alkalosis or a diet high in anions to induce a state of metabolic acidosis. Oral sodium bicarbonate was administered 1 h prior to glucose tolerance testing to assess the effect of correction of metabolic acidosis on insulin responsiveness. The glucose tolerance test (500 mg of glucose/kg BW infused i.v. over 10 min) caused an acute increase in plasma glucose concentrations and an acute increase in plasma insulin concentrations. Plasma glucose concentrations were higher (P < .005) and plasma insulin concentrations were lower (P < .0001) in cows with metabolic acidosis than in cows with metabolic alkalosis. These data suggest that insulin secretion is impaired during metabolic acidosis, which may reduce the uptake of glucose by insulin- dependent tissues, which might account for the increased plasma glucose concentrations observed during the glucose tolerance testing of the acidotic cows.