Leucocyte Count of Herd Milk Compared to the Incidence of Mastitis

• Published in: Journal of dairy science Vol. 36; no. 12; pp. 1267 - 1271
• Main Authors: MacLeod, Patricia, Plastridge, W.N., Anderson, E.O., Gullet, V.N., Hale, H.H.
• Format: Journal Article
• Language: English
• Published: Champaign Elsevier Inc 01.12.1953; Am Dairy Sci Assoc; American Dairy Science Association
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(53)91632-4

The leucocyte counts of the milk from 31 herds were compared with the percentage of animals within these herds that gave evidence of mastitis, as determined by laboratory tests. Statistical analysis of the data collected for this study indicated that 78% of the variation in the average leucocyte counts of herd milk may be explained in terms of the percentage of mastitis animals within the herd. If the percentage of infected animals within a herd, as defined herein, is 40% or more, the average leucocyte count of the herd milk may be expected to be 1,000,000 or more leucocytes per milliliter of milk. In the herds included in this study S. agalactiae infection was associated with higher leucocyte counts in the herd milk than were the corresponding percentages of infection caused by organisms other than S. agalactiae. This association, however, was not sufficiently marked to be statistically significant at the 0.05 probability level.