title: Long term effects of Escherichia coli mastitis.
abstract: Escherichia coli is one of the most frequently diagnosed causes of bovine mastitis, and is typically associated with acute, clinical mastitis. The objective of the present study was to evaluate the long term effects of intramammary infections by E. coli on milk yield and quality, especially milk coagulation. Twenty-four Israeli Holstein cows diagnosed with clinical mastitis due to intramammary infection by E. coli were used in this study. Mean lactation number, days in milk (DIM) and daily milk yield (DMY) at the time of infection was 3.3 ± 1.3, 131.7 days ± 78.6 and 45.7 L ± 8.4, respectively. DMY, milk constituents, somatic cells count (SCC), differential leukocytes count and coagulation parameters were subsequently assessed. Two patterns of inflammation were identified: 'short inflammation', characterized by <15% decrease in DMY and <30 days until return to normal (n = 5), and 'long inflammation', characterized by >15% decrease in DMY and >30 days to reach a new maximum DMY (n = 19). The estimated mean loss of marketable milk during the study was 200 L/cow for 'short inflammation' cases, and 1,500 L/cow for 'long inflammation' ones. Significant differences between 'short' and 'long inflammation' effects were found in almost all parameters studied. Long-term detrimental effects on milk quality were found regardless of clinical or bacteriological cure of affected glands.
authors.affiliation: National Mastitis Reference Center, Kimron Veterinary Institute, Ministry of Agriculture and Rural Development, P.O. Box 12, Bet Dagan 50250, Israel; Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environmental Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel.
authors.forename: Shlomo E
authors.initials: SE
authors.lastname: Blum
authors.affiliation: Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environmental Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel.
authors.forename: Elimelech D
authors.initials: ED
authors.lastname: Heller
authors.affiliation: National Mastitis Reference Center, Kimron Veterinary Institute, Ministry of Agriculture and Rural Development, P.O. Box 12, Bet Dagan 50250, Israel. Electronic address: leitnerg@moag.gov.il.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Leitner
mesh_terms: D000818:Animals; D002417:Cattle; D003612:Dairying; D004926:Escherichia coli / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000503:physiopathology / Q000662:veterinary*; D005260:Female; D007249:Inflammation / Q000662:veterinary; D007774:Lactation; D008414:Mastitis, Bovine / Q000382:microbiology / Q000503:physiopathology*; D008892:Milk / Q000737:chemistry* / Q000378:metabolism* / Q000382:microbiology
keywords: Dairy; Escherichia coli; Leukocyte; Mastitis; Milk quality