title: Changes in plasma volatile fatty acids in response to weaning and feed intake in young calves.
abstract: Effects of weaning age on plasma VFA were examined using 16 Holstein heifer calves. Animals entered the study at 6 +/- 3.5 d of age and were fed 1.8 kg milk twice daily to 28 (early weaning) or 56 d (late weaning) and a commercial pelleted calf starter from 0 (early) or 28 (late) d. Blood was sampled once weekly for 14 wk. Total blood concentrations of VFA, acetate, propionate, and butyrate were higher in calves weaned early. Difference between treatments was greatest during wk 5 to 8, after early calves had been weaned. Total VFA and acetate were both highly correlated with grain intake (r = .77), whereas propionate (r = .47) and butyrate (r = .56) were less highly correlated. Data indicate that blood VFA responded rapidly to dry feed intake, and adaptation to high grain diets was complete by 1 to 2 wk postweaning.
authors.affiliation: Department of Animal Science, University of Tennessee, Knoxville 37901.
authors.forename: J D
authors.initials: JD
authors.lastname: Quigley
authors.forename: Z P
authors.initials: ZP
authors.lastname: Smith
authors.forename: R N
authors.initials: RN
authors.lastname: Heitmann
mesh_terms: D000085:Acetates / Q000097:blood; D000818:Animals; D002087:Butyrates / Q000097:blood; D002417:Cattle / Q000097:blood*; D004435:Eating / Q000502:physiology*; D005232:Fatty Acids, Volatile / Q000097:blood*; D005260:Female; D016018:Least-Squares Analysis; D011422:Propionates / Q000097:blood; D014886:Weaning
chemical_list: D000085:Acetates; D002087:Butyrates; D005232:Fatty Acids, Volatile; D011422:Propionates