SOMATIC-CELL COUNTS, MASTITIS AND MILK-PRODUCTION IN SELECTED ONTARIO DAIRY HERDS

  • 1 January 1982
    • journal article
    • research article
    • Vol. 46  (1) , 12-16
Abstract
Somatic cell counts were performed monthly on bulk tank milk samples for all producers in the Ontario counties of Hastings, Lennox/Addington and Prince Edward throughout 1978 and 1979. Other data were obtained via a structured questionnaire and from the records of the Ontario Milk Marketing Board. Many producers have not adopted practices that have been advocated for the integrated control of mastitis. For example, 43.3% of producers surveyed used single service paper towels, 63.3% regularly used teat dip and 56.5% dry cow therapy. The mean of the average monthly somatic cell count for all producers for 1978 was 621.1 .times. 103 cells/ml. This latter value was used to divide the producers into case (higher than average) and control (lower than average) groups. Control herds averaged 95.9 l more shipped milk/cow per mo. than case herds. Milk from control herds averaged 0.22% points higher than case herds for each of average fat and lactose, and 0.16% points higher for protein. The linear regression of monthly shipped milk on the respective monthly bulk tank somatic cell count indicated a loss of of 13.26 l/cow per mo. for each 100,000 increase in somatic cell count.