title: Changes in blood glucose, nonesterified fatty acids, and ketones in response to weaning and feed intake in young calves.
abstract: Effects of weaning age on blood glucose, ketones, and nonesterified fatty acids were examined using 16 Holstein heifer calves. Animals entered the study at 6 +/- 3.5 d of age and were fed 1.8 kg of milk twice daily to 28 (early weaning) or 56 d (late weaning) and a commercial pelleted calf starter from 0 (early) or 28 d (late). Blood was sampled once weekly for 14 wk and analyzed for beta-hydroxybutyrate and acetoacetate. Plasma was analyzed for glucose and nonesterified fatty acids. Blood beta-hydroxybutyrate increased with increasing grain intake and was greater during wk 0 to 4 and 5 to 8 in calves weaned early than in those weaned late. Blood acetoacetate followed trends similar to beta-hydroxybutyrate and averaged 23.8 and 16.1 microM in calves weaned early and late, respectively. Plasma glucose and nonesterified fatty acids declined with age and were lower during 5 to 8 wk in calves weaned early. Data suggest that ketone concentrations resulted from alimentary ketogenesis, which increased rapidly after weaning.
authors.affiliation: Department of Animal Science, University of Tennessee, Knoxville 37901.
authors.forename: J D
authors.initials: JD
authors.lastname: Quigley
authors.forename: L A
authors.initials: LA
authors.lastname: Caldwell
authors.forename: G D
authors.initials: GD
authors.lastname: Sinks
authors.forename: R N
authors.initials: RN
authors.lastname: Heitmann
mesh_terms: D020155:3-Hydroxybutyric Acid; D000090:Acetoacetates / Q000097:blood; D000821:Animal Feed; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002417:Cattle / Q000097:blood*; D004435:Eating / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D006885:Hydroxybutyrates / Q000097:blood; D007657:Ketone Bodies / Q000097:blood*; D016018:Least-Squares Analysis; D011897:Random Allocation; D014886:Weaning; D015430:Weight Gain
chemical_list: D000090:Acetoacetates; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D006885:Hydroxybutyrates; D007657:Ketone Bodies; D020155:3-Hydroxybutyric Acid