|
|
||||||||
Department of Animal Science, Macdonald College of McGill University, 21,111 Lakeshore Road, Ste. Anne de Bellevue, Quebec H9X 1C0 Canada
ABSTRACT
A total of 774 individual milk samples were collected from 66 Holstein cows between October 1987 and April 1988. Samples were analyzed for plasmin, plasminogen, and SCC. An increase in SCC from less than 250,000/ml to more than 1,000,000/ml resulted in an increase of plasmin, plasminogen, and serum albumin by 105, 74, and 140%, respectively. Plasminogen, plasmin, and serum albumin followed similar trends that are expected for components from blood that gain access to the alveolar lumen through ruptured epithelium caused by mastitis. Increased plasmin is the direct result of this process rather than an increase in activation of plasminogen to plasmin. The plasminogen to plasmin ratio supports this interpretation, being 4.7 at 250, 000 SCC/ml and 4.0 when SCC exceeded 1 million/ml. Plasmin and plasminogen concentrations were also increased during lactation to reach peak values immediately before the dry period. However, in this case, ratio of plasminogen to plasmin was 6.55 during early lactation and decreased by half to 3.29 during the latest stage, indicating that considerable activation of plasminogen to plasmin occurred during the latter part of lactation. Mammary epithelium is not compromised at this stage, as shown by low (.8 mg/ml) serum albumin concentration in milk. Two mechanisms responsible for increased milk plasmin include influx of plasmin from blood during mastitis and increased activation of plasminogen as lactation progresses.
This article has been cited by other articles:
![]() |
V. Castillo, X. Such, G. Caja, R. Casals, E. Albanell, and A. A. K. Salama Effect of Milking Interval on Milk Secretion and Mammary Tight Junction Permeability in Dairy Ewes J Dairy Sci, July 1, 2008; 91(7): 2610 - 2619. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Theodorou, A. Kominakis, E. Rogdakis, and I. Politis Factors Affecting the Plasmin-Plasminogen System in Milk Obtained from Three Greek Dairy Sheep Breeds with Major Differences in Milk Production Capacity J Dairy Sci, July 1, 2007; 90(7): 3263 - 3269. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. R. Rastani, N. S. Del Rio, T. F. Gressley, G. E. Dahl, and R. R. Grummer Effects of Increasing Milking Frequency During the Last 28 Days of Gestation on Milk Production, Dry Matter Intake, and Energy Balance in Dairy Cows J Dairy Sci, April 1, 2007; 90(4): 1729 - 1739. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Rabot, F. Sinowatz, B. Berisha, H. H. D. Meyer, and D. Schams Expression and Localization of Extracellular Matrix-Degrading Proteinases and Their Inhibitors in the Bovine Mammary Gland During Development, Function, and Involution J Dairy Sci, February 1, 2007; 90(2): 740 - 748. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Miller, L. Delbecchi, D. Petitclerc, G. F. Wagner, B. G. Talbot, and P. Lacasse Effect of Stage of Lactation and Parity on Mammary Gland Cell Renewal J Dairy Sci, December 1, 2006; 89(12): 4669 - 4677. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |