Preliminary field evidence for the association of clinical mastitis with altered interestrus intervals in dairy cattle

D. A. Moore, James S Cullor, Robert Bondurant, W. M. Sischo

Research output: Contribution to journalArticle

72 Scopus citations


Clinical mastitis and reproductive records from two southern California dairy herds were used in a cross-sectional study to determine the risk of an altered interestrus interval following clinical mastitis. An altered interestrus interval was defined as cycles occurring at either less than 18 day or more than 24-day intervals. The data were stratified by herd to assess herd differences and by lactation number to assess confounding by cow parity. The predominant pathogen isolated from mastitis cases in Herd 1 was Staphylococcus aureus, whereas the predominant pathogens in Herd 2 were gram-negative isolates. Cows in Herd 1 which had coliforms cultured from mastitic milk were excluded in the analysis for comparison with Herd 2. In Herd 1, cows with clinical mastitis were less likely to have an altered interestrus interval (Relative Risk [RR]=0.9; 95% Confidence Interval [CI]=0.6,1.6) than herdmates without clinical mastitis. However, cows in Herd 2 were almost two times more likely to have an altered interestrus interval following an episode of clinical mastitis compared to herdmates without clinical mastitis (RR=1.6; 95% CI=1.3,2.0). Because herd management practices differ and could cause differences in mastitis and reproductive outcomes at the dairies, this preliminary field evidence should be followed by prospective studies of luteal function after clinical coliform mastitis.

Original languageEnglish (US)
Pages (from-to)257-265
Number of pages9
Issue number2
StatePublished - 1991



  • bovine
  • coliform mastitis
  • estrous cycles

ASJC Scopus subject areas

  • Animal Science and Zoology
  • veterinary(all)

Cite this