Relationships between blood Se concentrations and milk somatic cell counts in dairy cows

Authors: Grace ND, Knowles SO, Lee J
Publication: New Zealand Veterinary Journal, Volume 45, Issue 4, pp 171-172, Aug 1997
Publisher: Taylor and Francis

Animal type: Cattle, Livestock, Production animal, Ruminant
Subject Terms: Bacterial, Diet/rations/food, Mammary gland/udder, Mastitis, Infectious disease, Milk, Nutrition/metabolism, Selenium, Trace elements
Article class: Correspondence

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Abstract: Mastitis continues to be a problem in dairy cows despite the use of control strategies of teat sprays and dry cow therapy. One measure of the prevalence of clinical mastitis is milk somatic cell counts (SCC). Under New Zealand Livestock Improvement Corporation (LIC) criteria, 2-year-old and older cows having SCC greater than 120 000 and 150 000 cells/ml respectively are considered likely to have infected udders. Clinical mastitis may be associated with Se status, as Se enhances the immune response through the mobilisation and function of neutrophils. In Se-deficient cows, bactericidal activity of neutrophil leukocytes isolated from the mammary gland is less than normal against S. aureus and E. coli, and glutathione peroxidase activity (GSH-Px, a Se enzyme) of these phagocytic cells is reduced. As neutrophils have a primary role in controlling bacterial pathogens in the mammary gland, impared phagocytic function could lead to decreased resistnace to infection. In the USA…

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