Evidence for Impaired Metabolism in Liver during Induced Lactation Ketosis of Dairy Cows

Abstract

Ketosis was induced in four lactating dairy cows at an average of 36 d postpartum and 24 d after initiation of a protocol for inducing ketosis. Liver and adipose biopsies were taken at five stages; once prepartal, once early postpartal, once during an induction protocol, once during ketosis, and once during recovery after treatment of ketosis. At each stage, in vitro estimates were made of capacities of liver slices for gluconeogenesis, fatty acid oxidation, and ketogenesis and of capacities of adipose tissue slices for lipogenesis and lipolysis. There were no significant differences for any metabolic capacity between prepartal and early postpartal stages; however, a significant decrease in hepatic metabolic activity was associated with ketosis. Gluconeogenic rates from all substrates tested were decreased significantly during ketosis, and similar decreases were measured for oxidation of gluconeogenic substrates and fatty acids. Treatment of ketosis resulted in complete recovery from impairments of metabolism in liver. Results suggest that a prolonged energy deficit, plus a major influx of ketone precursors, is accompanied by eventual hepatic impairment, that clinical ketosis is associated with this impairment, and that the impairment is reversed by effective treatment of ketosis. © 1986, American Dairy Science Association. All rights reserved.