title: Effect of colostrum intake on alpha-lactalbumin concentrations in serum of calves.
abstract: Seven Friesian calves were fed colostrum for four days beginning within 24 hours of birth, and milk thereafter. The concentration of alpha-lactalbumin in serum was measured by specific radioimmunoassay and compared to IgG assayed by electroimmunodiffusion. Serum concentrations of alpha-lactalbumin peaked at 387 +/- 85 ng ml-1 within eight hours of initial intake of colostrum, declining to 12 +/- 3 ng ml-1 by day 6. IgG rose steadily to 17 mg ml-1 by 48 hours of birth and remained relatively constant thereafter. The temporal pattern of alpha-lactalbumin in serum following colostrum intake confirms previous studies suggesting reduced absorption of colostral proteins between 24 and 36 hours. The presence of variable amounts of alpha-lactalbumin in serum even after 17 days, however, indicates limited transfer of milk-derived proteins across the gut at this time. The data further show that cessation of maximal gut transfer does not relate to molecular weight of transferred protein.
authors.affiliation: Dairying Research Corporation, Ruakura Agricultural Centre, Hamilton, New Zealand.
authors.forename: C G
authors.initials: CG
authors.lastname: Prosser
authors.forename: S J
authors.initials: SJ
authors.lastname: Eichler
authors.forename: V C
authors.initials: VC
authors.lastname: Farr
authors.forename: S R
authors.initials: SR
authors.lastname: Davis
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood*; D002417:Cattle / Q000097:blood*; D003126:Colostrum / Q000502:physiology*; D005779:Immunodiffusion / Q000379:methods / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood; D007422:Intestines / Q000502:physiology; D007768:Lactalbumin / Q000097:blood*; D011863:Radioimmunoassay / Q000662:veterinary
chemical_list: D007074:Immunoglobulin G; D007768:Lactalbumin