title: Mammary immunoglobulin transfer rates following prepartum milking.
abstract: Colostrum formation is thought to occur slowly over an extended period (4wk) prepartum. Furthermore, colostrum formation is highly variable among cows in total volume, IgG1concentration, and mass obtained at first postpartum milking. Recent work has suggested that a rapid transfer of IgG1to secretions may occur if animals are milked prepartum. Our objective was to establish the concentration, mass, and mass transfer rates of IgG1in multiparous Holstein cows (n=11, parity=3.6±1.1) milked prepartum (-74 to -1h) and again around 4h postpartum. Blood concentrations of IgG1were very low (<1mg/mL) in 7 cows at prepartum milking and did not decline following prepartum milking. Cows showed variability in the capacity to recover total volume, IgG1concentration, and IgG1mass. Three groupings of cows were considered based on the time between the 2 milkings (prepartum + 4h postpartum): long-time (-74 to -54h, n=3), medium-time (-25 to -17h, n=4), and short-time (< -13h, n=4) groups. The average rates of transfer of these groups were 1.4±0.8, 3.0±1.3, and 25.1±15.8g/h, respectively. The data indicate that a longer time between prepartum and postpartum milking is not a main factor in IgG1secretion transfer. Furthermore, because blood concentrations did not change after prepartum milking and the mass of blood plasma IgG1was not sufficient to account for the mass occurring in postpartum colostrum, a source of IgG1other than blood circulation appears to be present during colostrogenesis.
authors: Department of Animal Science, The Pennsylvania State University, University Park 16802; Veterinary Physiology, Vetsuisse Faculty, University of Bern, Switzerland CH 3001. Electronic address: crb@psu.edu.
authors: C R
authors: CR
authors: Baumrucker
authors: Department of Animal Science, The Pennsylvania State University, University Park 16802.
authors: C D
authors: CD
authors: Dechow
authors: Department of Animal Science, The Pennsylvania State University, University Park 16802.
authors: A L
authors: AL
authors: Macrina
authors: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Switzerland CH 3001.
authors: J J
authors: JJ
authors: Gross
authors: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Switzerland CH 3001.
authors: R M
authors: RM
authors: Bruckmaier
mesh_terms: D000818:Animals; D002417:Cattle; D003126:Colostrum; D005260:Female; D007074:Immunoglobulin G; D007774:Lactation; D008892:Milk / Q000378:metabolism*; D010298:Parity; D049590:Postpartum Period
chemical_list: D007074:Immunoglobulin G
keywords: colostrum; immunoglobulin; mammary; transfer rates