Norwegian mastitis control

INTroDuCTIoN Mastitis is defined as any inflammatory process affecting the mammary gland (International Dairy Federation 1987). Clinical mastitis (CM) is defined as mastitis causing clinical signs in the udder or visible changes in the milk and according to the recommendation of the International Dairy Federation (IDF), is divided into severe, moderate or mild (International Dairy Federation 1999). In the Norwegian recording system, moderate and severe CM is reported using the same health code: 303 (Østerås et al. 2007). Subclinical mastitis is only detected by laboratory methods such as the analysis of somatic cell count (SCC) or other parameters related to the inflammatory process. The main motivation for mastitis control is an economic one as stated by Morris (1975). Little scientific work has concentrated on the subject of economics and mastitis, although the IDF has tried to summarise its relevance (International Dairy Federation 2005). The subject was also discussed in a recently published review paper (Halasa et al. 2007). The data revealed a large variation in the calculated costs and benefits of mastitis and mastitis management between the different studies. In addition to this, it is clear that important factors were ignored in some of the studies. As economic gain is a major goal, economic parameters must be included when mastitis control programmes are evaluated. In Norway, the costs of mastitis are calculated and presented for each farm during each recording period (Table 1). Other important parameters are animal welfare and farmer welfare. Most clinical cases of mastitis are painful for the effected animal and create a lot of work for the farmer. Subclinical mastitis may also be painful for the cow (Eshraghi et al. 1999). Mastitis causes changes in milk content and characteristics such as shelf life ABSTrACT This paper describes the methods and results of the Norwegian Mastitis Control Program implemented in 1982. The program has formed an integral part of the Norwegian Cattle Health Services (NCHS) since 1995. The NCHS also have specific programs for milk fever, ketosis, reproduction and calf diseases. The goal of the program is to improve udder health by keeping the bulk milk somatic cell count (BMSCC) low, to reduce the use of antibiotics, to keep the cost of mastitis low at herd level and improve the consumers’ attitude to milk products. In 1996, a decision was made to reduce the use of antibiotics in all animal production enterprises in Norway by 25% within five years. Relevant data has been collected through the Norwegian Cattle Herd Recording System (NCHRS); including health records since 1975 and somatic cell count (SCC) data since 1980. These data have been integrated within the NCHRS. Since 2000, mastitis laboratory data have also been included in the NCHRS. Data on clinical disease, SCC and mastitis bacteriology have been presented to farmers and advisors in monthly health periodicals since 1996, and on the internet since 2005. In 1996, Norwegian recommendations on the treatment of mastitis were implemented. Optimal milking protocols and milking machine function have been emphasised and less emphasis has been placed on dry cow therapy. A selective dry cow therapy program (SDCTP) was implemented in 2006, and is still being implemented in new areas. Research demonstrates that the rate of clinical mastitis could be reduced by 15% after implementing SDCTP. The results so far show a 60% reduction in the clinical treatment of mastitis between 1994 and 2007, a reduction in BMSCC from 250,000 cells/ml to 114,000 cells/ml, and a total reduction in the mastitis cost from 0.23 NOK to 0.13 NOK per litre of milk delivered to the processors, corresponding to a fall from 9.2% to 1.7% of the milk price, respectively. This reduction is attributed to changes in attitude and breeding, eradicating bovine virus diarrhoea virus (BVDV) and a better implementation of mastitis prevention programmes.