title: Ultrasonographic measurement of abomasal volume, location, and emptying rate in calves.
abstract: OBJECTIVE
  To develop and validate an ultrasonographic method for measuring abomasal volume, location, and emptying rate in suckling calves.
  
  
  METHODS
  9 male Holstein calves < 40 days of age.
  
  
  METHODS
  Before and after calves were fed different volumes of milk replacer or 2 L of oral electrolyte solutions, ultrasonographic measurements of abomasal dimensions (width, length, and height) were obtained by applying a 3.5-MHz sector probe to the ventral aspect of the abdomen in the transverse and sagittal planes. Abomasal volume was calculated from the ultrasonographic measurements by modeling the abomasum as an ellipsoid and by use of a power exponential equation to calculate the half-time of abomasal emptying (t1/2).
  
  
  RESULTS
  Preprandial abomasal volume was 20 to 137 mL. All 3 abomasal dimensions increased during feeding and after suckling, and the abomasum was symmetrically located about the midline of the ventral aspect of the abdomen. Strong linear relationships were identified between ultrasonographic and suckled volumes, between ultrasonographic and scintigraphic heights, and between ultrasonographic and scintigraphic lengths. Ultrasonographic t1/2 was linearly related to scintigraphic t1/2; the latter is regarded as the gold standard measure of gastric emptying rate.
  
  
  CONCLUSIONS
  Ultrasonographic evaluation of the abomasum appears to provide a practical, rapid, noninvasive, and accurate method for determination of abomasal volume, location, and emptying rate in suckling calves.
authors.affiliation: Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wittek
authors.forename: Peter D
authors.initials: PD
authors.lastname: Constable
authors.forename: Tessa S
authors.initials: TS
authors.lastname: Marshall
authors.forename: Sonia S
authors.initials: SS
authors.lastname: Crochik
mesh_terms: D000018:Abomasum / Q000000981:diagnostic imaging*; D000818:Animals; D002417:Cattle / Q000033:anatomy & histology* / Q000502:physiology*; D005746:Gastric Emptying / Q000502:physiology*; D008962:Models, Theoretical; D009929:Organ Size; D011877:Radionuclide Imaging / Q000662:veterinary; D012044:Regression Analysis; D014463:Ultrasonography