A major problem with research into endemic diseases such as mastitis is that their multi-factorial nature means that any control programme has to involve a number of simultaneous management changes; a change in just one risk factor alone may improve mastitis control only marginally, not at all or may even increase the risk of mastitis with a different pathogen. For example there is evidence in the literature to suggest that some control measures directed against the control of contagious mastitis pathogens (those that spread from cow-to-cow) may in fact increase the risk of environmental mastitis.
Whilst there is an extensive literature identifying specific risk factors for, and interventions to, control bovine mastitis there was a need to test whether risk factors associated with clinical mastitis were indeed causal rather than explanatory and whether or not a control plan that used these risk factors could be implemented and be effective at reducing the incidence of mastitis in commercial U.K. herds.
To this end, a randomised clinical trial was carried out on 52 commercial dairy herds in England and Wales in 2004 with the aim of determining whether a well-specified mastitis control plan (The DairyCo Mastitis Control Plan), implemented in herds with an increased incidence of clinical mastitis, would reduce the incidence of disease as well as the incidence of increases in somatic cell counts of individual cows. Two RCVS-recognised veterinary specialists developed a clearly defined plan for the diagnosis and control of bovine mastitis based on an extensive review of the research literature.
Twenty-six herds (intervention herds or 'Plan' herds) were allocated at random to receive the Plan from the start of the study period, with the other 26 herds receiving the Plan after one year.
After one year, the incidence of cows affected with clinical mastitis had increased by 19% in control herds but had decreased by 4% in the intervention (Plan) herds. The proportional change in incidence of clinical mastitis is illustrated in figure 1.
Results from statistical modelling (to include potential confounding factors) showed a significant, 22% reduction in the proportion of cows affected with clinical mastitis on the intervention (Plan) farms compared with the control farms. Significant reductions were also shown in the incidence of clinical mastitis and new infections as measured by change in somatic cell counts.
Further exploration of the study data, demonstrated that the degree of compliance with the Plan recommendations had a significant impact on outcome as illustrated in Figure 2. The eight intervention herds with the highest level of compliance (>66% of recommendations implemented)) made a total of 80 management changes, a mean of 10 per farm, compared to just 4.2 management changes for herds with the lowest level of compliance (<33% of recommendations implemented).
The DairyCo Mastitis Control Plan is certainly not the only way and may not be the best way to control bovine mastitis, but it uses research evidence wherever possible and involves all areas of farm management in a 'manageable' way. It is hoped that the Mastitis Control Initiative currently underway and outlined in this website will enable the industry to make progress in the control of what is one of the most important endemic diseases in the UK.
An important facet of the mastitis control plan is the collation and interpretation of both somatic cell count and clinical mastitis data. There are three providers of milk recording services in the UK: CIS, NMR and QMMS.
|Last Updated on Thursday, 06 March 2014 16:00|