Vet. Res. 34 (2003) 475-491
DOI: 10.1051/vetres:2003027

Production effects related to mastitis and mastitis economics in dairy cattle herds

Henri Seegers, Christine Fourichon and François Beaudeau

Unit of Animal Health Management, UMR 708 ENVN/INRA, National Veterinary School, BP 40706, 44307 Nantes Cedex 03, France
(Received 17 December 2002, accepted 27 May 2003)

Abstract
Mastitis is the most prevalent production disease in dairy herds world-wide and is responsible for several production effects. Milk yield and composition can be affected by a more or less severe short-term depression and, in case of no cure, by a long-acting effect, and, sometimes, an overlapping effect to the next lactation. Summary values in the literature for losses of milk production were proposed at 375 kg for a clinical case (5% at the lactation level) and at 0.5 kg per 2-fold increase of crude SCC of a cow. Due to the withdrawal period after treatment, composition changes in milk can almost be neglected in economic calculations. Lethality rate for clinical mastitis is very low on the average, while anticipated culling occurs more frequently after clinical and subclinical mastitis (relative risk between 1.5 and 5.0). The economics of mastitis needs to be addressed at the farm level and, per se, depends on local and regional epidemiological, managerial and economic conditions. To assess the direct economic impact of mastitis, costs (i.e. extra resource use) and losses (i.e. reduced revenues) have to be aggregated. To support decision making for udder health control, it is necessary to use a marginal approach, based on the comparison of the losses avoided and the additional costs of modified plans, compared to the existing ones.

Key words: dairy cattle / mastitis / milk somatic cell count / milk yield / longevity / economics

Correspondence and reprints: Henri Seegers seegers@vet-nantes.fr

© INRA, EDP Sciences 2003