Field survey of clinical mastitis in low somatic cell count herds
| Autor: | H.R. Conrad, W. D. Hueston, B. L. Brockett, D. A. Todhunter, J.S. Hogan, L. E. Heider, K.L. Smith, D. E. Pritchard, K.H. Hoblet, G. L. Bowman, P.S. Schoenberger |
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| Rok vydání: | 1989 |
| Předmět: |
Veterinary medicine
Staphylococcus Ice calving Cell Count medicine.disease_cause Staphylococcal infections Animal science Enterobacteriaceae Pregnancy Lactation Streptococcal Infections Genetics medicine Animals Mastitis Bovine business.industry Enterobacteriaceae Infections Streptococcus Staphylococcal Infections medicine.disease Mastitis medicine.anatomical_structure Streptococcus agalactiae Staphylococcus aureus Herd Animal Science and Zoology Cattle Female Seasons business Somatic cell count Food Science |
| Zdroj: | Journal of dairy science. 72(6) |
| ISSN: | 0022-0302 |
| Popis: | Nine commercial dairy herds, each with low herd milk somatic cell counts, were monitored for 1 yr to determine prevalence of intramammary infections and rates of clinical mastitis. Staphylococcus species was the bacterial group most frequently isolated from quarters at calving and at drying off. Environmental streptococci and coliform intramammary infections totaled less than 6% of quarters at both calving and at drying off. Staphylococcus aureus were isolated from less than 1% of quarters and Streptococcus agalactiae from 0% of quarters at both calving and drying off. A total of 646 clinical cases of mastitis were diagnosed in 548 quarters of 406 cows. Mean rate of clinical mastitis among herds was .457 clinical cases/305 cow-days. Rates of clinical mastitis ranged among herds from .273 to .748 clinical cases/305 cow-days. Conforms and bacteriologically negative and environmental streptococci accounted for 82.3% of clinical cases. Rates of clinical mastitis and severity of clinical signs differed among herds, seasons of the year, parity groups, and stages of lactation. Rates of clinical mastitis were highest during summer, in first lactation cows, and during the first 7 d of lactation. |
| Databáze: | OpenAIRE |
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