This paper investigated the implementation and evaluation of the efficacy of a HACCP-based approach for the control of mastitis on six Irish dairy farms from a technical and sociological perspective. Overall, the programme was useable and verifiable on all participating farms. However, the control of mastitis on the participating farms generally reflected the variable compliance among farmers.
The initial investigative visit was essential as it allowed the veterinarian to identify specific problems on each farm so that relevant recommendations could be made. There were varying levels of compliance throughout the course of the study, reflective of the willingness of the farmers to translate their motivations into practice. For example, Farmer 2 was very reluctant to implement most of the recommended control strategies from the initial commencement of the study. On the other hand, Farmer 1 realised from the outset that preventative measures were fundamental to improving SCC in the long term.
The lack of a consistent relationship between compliance rates and significant changes in SCC could be attributed to various factors. Farmer 1, who had the highest compliance rate, did not experience any significant changes in SCC of the bulk milk tank or herd milk recording. This could be contributed to a change of calving seasons (from all spring calving to spring and autumn calving) in the middle of the project and the change of milk processor (the new milk processor was a lot less vigilant in hygienic standards and feedback of information). Farmer 2, whose compliance rate was the lowest over all participants, still managed to decrease the bulk milk tank SCC significantly which indicates that even partial compliance with the programme resulted in improved management of the bulk milk tank. This was certainly the case for Farmer 6, who had a significant increase in herd milk recorded SCC and a significant decrease in SCC of the bulk milk tank. However his selective adoption of focusing on the segregation of 10 high SCC problem cows, was helping him to score high on compliance, even though it was only a short-term strategy.
An increasing number of studies recognise the impact of human attitudinal factors on mastitis prevention measures [6, 7, 18]. The inclusion of a social science approach in the study facilitated the identification of farmer motivation and attitudes, and the related factors that influenced decisions to implement control measures. Farmer perceptions and experiences of the communication between veterinarian and farmer and the facilitating mechanisms of the HACCP-based approach influenced their decisions to comply with study recommendations (Figure 4). A study of an Australian national mastitis control programme, "Countdown DownUnder", by Brightling , provides evidence pointing towards the importance of the communication process in helping farmers understand the issues at hand - in order to improve compliance, particularly in the communication of information that is often equivocal. Regular communication (through visits and phone calls) contributes to a greater understanding of the objectives of the study and provides the farmer with the opportunity to raise issues of concern or seek clarification, resulting in greater compliance.
The transfer and communication of knowledge is significant in influencing compliance. The information and recommendations communicated were validated by farmers' perceptions of the veterinarian's level of expertise specific to mastitis. The relationship between veterinarian and farmer in agreeing targets was also important, 'I had input as well into the targets we set, which was important. Because you have to take into account the farm and your own situation. So it's important that the farmer has input into the targets'. Farmers reported throughout the project that the HACCP-based approach allowed them to develop a greater understanding of mastitis as a disease and of its specific situation to their individual farm; this approach increased focus and awareness, and encouraged a sense of greater vigilance on a daily basis.
Regular communication and the opportunity for negotiation between veterinarian and farmer in this study were facilitated by the relatively frequent visits and contact. It would have been beneficial to visit the farms more frequently e.g. once a fortnight but for practical reasons, unfortunately this was not possible. However, the approach adopted was beneficial in maintaining focus and in the development of greater awareness on the necessity of daily vigilance. This change in attitude among the participating farmers during the study was largely facilitated by the relationships formed between farmers and the veterinarian. Although this finding was beyond the scope of this study, it does emphasise the importance of well-founded relationships and ongoing communication in the herd health sector. The process was also facilitated by the customised HACCP-based handbook, which provided farmers with information specific to their farm and allowed them to agree on and note what control measures would be implemented. However, despite this, compliance with all control measures was not achieved on all participating farms.
In the present study, control measures were fully implemented, partially implemented or not implemented at all. Partial implementation was judged on the basis of the frequency and quality of implementation of the control measure. Greater compliance with suggested control strategies may have been achievable with a restructuring of the approach adopted during the study through more frequent farm visits and on-farm observations that would allow ideal coaching by the veterinarian and a greater transfer and intensity of information sharing. Farmers spoke of how frequent visits and communication provided a channel for the development of focus and awareness on their mastitis problem, with some farmers being compelled to complete certain measures because of upcoming visits. Repeating this study with a large group of farms would strengthen the value of performed statistics and could help detecting changes in SCC more successfully.
Sociological insights revealed the barriers identified by farmers when considering compliance with a control measure. These barriers were discussed with the farmer and more feasible, alternative approaches were identified and implemented, resulting in greater compliance. Leeuwis  argues that effective innovation involves developing a social learning process that includes negotiation, allowing all involved to reach a shared common view on desired goals, responsibilities and standards. The flexibility of this study approach was beneficial as it did allow farmers to negotiate and adjust certain control measures to adopt into their farm routine and infrastructural challenges whilst not reducing the overall planned effectiveness of the control programme. Although the HACCP-based approach allowed a degree of flexibility in the implementation of control measures, alternative measures should not be viewed as quick solutions that distract the farmer from key control measures.
Farmers were less likely to implement longer-term control strategies; for example, methods to decrease in-parlour spread of infection. This reflects farmers' reliance on the expectation of short-term positive results to justify the implementation of certain practices. This was certainly observed in the changes of SCC, which were overall not significant. This study showed that positive results, such as a reduction in the incidence of clinical mastitis or SCC played a significant role in informing farmers' decisions to continue with the implementation of a control measure. Notably, this study took place over a one-year period, arguably too short a time for considerable changes, if any, on the six farms. A discontinuation of the HACCP-based practices during the study, were related to the lack of beneficial outcomes and observable results on the farm. In light of this, therefore, it is necessary in a study of this nature to consider how best to manage farmer expectations in terms of their reliance on observable outcomes, noting the time period in which any such results could be experienced. The study farms were broadly representative of commercial Irish dairy farms within which herd health and production management programmes are generally not well developed. The recent creation of a national dairy herd health initiative (Animal Health Ireland) will radically change this situation in the future . However, there is little doubt that risk management programmes such as that developed in this study would be easier implemented on farms with established herd health and production management programmes .
The inclusion of information on specific topics such as subclinical mastitis in the customised HACCP- based handbook may have provided greater awareness and transfer of information on these issues. Overall, a lack of awareness on the prevalence of subclinical mastitis was apparent throughout - this was augmented by the failure of some farmers to milk record on a frequent basis. Increased discussion on the economic impact of high SCC would have encouraged farmers to move away from reliance on the point of penalisation (400,000 cells/ml) as a benchmark for somatic cell count levels. The customised HACCP-based handbook provided a means for information and monitoring of control measure-related activities. The failure to complete all monitoring sheets and the prevalence of transferring of data from other sources among some farmers may point to the need for readjustment of, and greater communication on, the purposes of this handbook , while an increase in coaching frequency could have improved the completion rate of the monitoring sheets. While they were supportive of the project and kept informed of the study, the research was conducted without the active participation of the farmers' private veterinary practitioners. Active involvement of the practitioners, after a period of initial training, may have had a beneficial effect by allowing increased frequency of coaching and reinforcement of the HACCP-based approach.