title: Serum lactoferrin concentrations in colostrum-fed calves.
abstract: OBJECTIVE
  To determine serum lactoferrin concentrations (SLFC) in neonatal calves before and after ingestion of colostrum and to develop models that predict SLFC as a function of colostral lactoferrin concentrations (CLFC) in calves.
  
  
  METHODS
  13 Holstein calves.
  
  
  METHODS
  Calves were fed 4 L of colostrum via oroesophageal feeder within 3 hours after birth. Serum samples were collected before ingestion of colostrum (day 0) and 2, 4, 6, and 7 days after birth. Colostrum and serum IgG concentrations were measured by use of radial immunodiffusion. The CLFC and SLFC were determined by use of an ELISA.
  
  
  RESULTS
  Mean +/- SD SLFC on days 0, 2, 4, 6, and 7 were 2.5+/-1.6 (range 0.47 to 71), 6.0+/-3.0 (range 2.0 to 16.6), 12.0+/-12.4 (range 0.0 to 43.5), 171+/-13.6 (range 2.2 to 39.4), and 13.6+/-16.4 (range 0.0 to 43.8) mg/ml, respectively. The SLFC on days 6 and 7 differed significantly from SLFC on day 0. The model that best estimated SLFC on day 6 predicted that (SLFC)2 was a function of the logarithm of relative efficiency of passive transfer (REPT) and ([CLFC]2 x [REPT]2), where R2 = 0.4. The model for SLFC on day 7 predicted that (SLFC)2 was a function of log(REPT), where R2 = 0.44.
  
  
  CONCLUSIONS
  Definitive evidence for passive transfer of lactoferrin via colostrum is lacking, because SLFC on day 2 or 4 were not significantly different than day 0. Relative efficiency of lactoferrin absorption was directly related to SLFC on day 6 but inversely related to SLFC on day 7.
authors.affiliation: Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Holloway
authors.forename: Jeff
authors.initials: J
authors.lastname: Lakritz
authors.forename: Jeff W
authors.initials: JW
authors.lastname: Tyler
authors.forename: Steven L
authors.initials: SL
authors.lastname: Carlson
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002417:Cattle / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D003126:Colostrum / Q000737:chemistry / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D005779:Immunodiffusion; D007074:Immunoglobulin G / Q000097:blood; D007781:Lactoferrin / Q000097:blood*; D008297:Male
chemical_list: D007074:Immunoglobulin G; D007781:Lactoferrin