Hemolytic and bactericidal activities of bovine complement in mammary secretions of cows during the early nonlactating (dry) period.
Hemolytic and bactericidal complement-dependent activities were measured in quarter mammary secretions obtained during the first 21 days of the nonlactating (dry) period from 8 Holstein-Friesian cows. We demonstrated an inhibition of hemolytic activity and bactericidal activity against a serum-sensitive Escherichia coli strain. Both hemolytic and inhibitory titers increased markedly during active involution. The bactericidal activity of dry secretions required a minimal threshold of complement and an inhibitory titer lower than the hemolytic titer.
D000818:Animals; D002417:Cattle; D003165:Complement System Proteins / Q000502:physiology*; D004926:Escherichia coli; D005260:Female; D006461:Hemolysis; D008321:Mammary Glands, Animal / Q000378:metabolism*
D003165:Complement System Proteins