The control of the level of staphylococcal contamination of the bovine udder by shed management

Abstract

Extract The establishment of intramammary infection in the dairy cow requires the initial exposure of the udder or quarter to bacteria. Thus, reduced exposure of the udders of cows to staphylococci should reduce the incidence of intramammary staphylococcal infections. Various methods have been described for preventing the exposure of the udder to bacteria (for review see Neave and Jackson, 1971 Neave, F. K. and Jackson, E. R. 1971. “The prevention of intramammary infection”. In The Control of Bovine Mastitis, Edited by: Dodd, F. H. and Jackson, E. R. 15–24. Reading: Nat. Inst. Res. Dairying. In [Google Scholar] ). Furthermore, as compared with the older cows in the herd, the first-lactation heifers calve with a low level of staphylococcal contamination of their udders (Munch-Petersen, 1968 Munch-Petersen, E. 1968. Incidence of udder infections arising at various stages of lactation of cows. Aust. vet. J., 44: 543–549. [Crossref], [PubMed], [Web of Science ®] [Google Scholar] , 1970 Munch-Petersen, E. 1970. Mastitis in bovine primiparae. Vet. Rec, 87: 568–574. [Google Scholar] ; Jones and Shannon, 1972 Jones, M. A. S. and Shannon, A. D. 1972. A study of the pattern of staphylococcal contamination of the udders of cows in a dairy herd. N.Z. vet. J., 20: 86–90. [Taylor & Francis Online] [Google Scholar] ). Davidson ( 1961 Davidson, I. 1961. Observations on the pathogenic staphylococci in a dairy herd during a period of six years. Res. vet. Sci., 2: 22–40. [Google Scholar] ) noted that the udder of the cow was the most important source of staphylococci for spread to other animals and that other sources, such as the milker's hands, were of secondary importance. Thus, a management policy aimed at reducing the exposure of the udders of heifers in the herd to staphylococci being shed in the milk of older cows should assist in the control of staphylococcal mastitis.