IGG CONCENTRATION IN MAMMARY SECRETIONS OF GOATS THROUGHOUT LACTATIONIN HEALTHY AND COAGULASE-NEGATIVE STAPHYLOCOCCI INFECTED UDDERS

Radial immunodiffusion was used to determine immunoglobulin (Ig)-G con centrations in 16 mammary secretions from uninfected udder halves and in 10-14 secretions from halves subclinically infected with coagulase- negative staphylococci in goats throughout lactation. IgG concentratio ns in samples from uninfected halves decreased rapidly during the firs t week after parturition (P < 0.001), thenceforth falling slowly up to 30 d post-partum (P < 0.001). From 30 d post-partum to 180 d of lacta tion, IgG concentration showed a continuous decline to the end of the experiment but these changes were not statistically significant until 150 d after kidding (P < 0.01). IgG concentrations in lacteal secretio ns of halves harbouring coagulase-negative staphylococci showed a simi lar pattern, from the first month of lactation, to that observed in he althy udder halves, but concentrations were always lower. These differ ences were significant from 2 months after parturition (P < 0.001). Ig G concentrations were compared with somatic cell counts obtained using an automatic counter (Fossomatic). (C) 1997 Elsevier Science Ltd.