Abstract

Infusion of antibiotics into the udder at the end of the lactating period (“dry cow therapy”; DCT) is an essential control measure for bovine mastitis (Smith et al., 1967). Dry cow therapy eliminates existing intramammary infections (IMI) and reduces the incidence of new infections over the dry period with a resultant reduced prevalence of IMI at the commencement of the subsequent lactation (Smith et al., 1967; Harmon et al., 1986). The cure rate of existing infections after DCT has been reported as between 60-90% (Pankey et al., 1982; Sol et al., 1994; Browning et al., 1990; Williamson et al., 1995). Dry cow therapy reduces the new IMI rate by approximately 50% (Browning et al., 1994; Williamson et al., 1995). Infusion of antibiotics at the end of lactation in dairy goats (“dry-goat therapy”; DGT) has been reported to cure between 66% and 100% of existing IMI (Fox et al., 1992; Poutrel & de Cremoux, 1995; Poutrel et al., 1997). However, the efficacy of DGT in reducing the new infection rate over the dry period has not been examined. The aim of this trial was to assess the efficacy of intramammary antibiotic treatment of dairy goats at the end of lactation in curing existing mammary gland infections and reducing the incidence of new infections over the dry period and early in the subsequent lactation.

FM, Anniss, and S McDougall

Proceedings of the New Zealand Society of Animal Production, Volume 62, Palmerston North, 19-21, 2002