Purpose: To examine the role of agricultural education and extension in influencing the adoption of best practice with regard to herd-level mastitis management. Design/Methodology/Approach: Somatic cell count (SCC) is an indicator of herd health with regard to mastitis and is negatively related to productivity and profitability. Panel data regression methods are utilised here to quantify the role of agricultural education and extension in reducing cell count and in influencing farmer best practice with regard to herd health. The impact of education and extension on farmer uptake of milk recording is of particular interest. Data utilised is farm-level Farm Accountancy Data Network (FADN) data for Ireland over a five-year period (2008-2012). Findings: Farmer uptake of formal agricultural training and liaison with agricultural extension services are shown to significantly improve mastitis herd health. Collectively, education, extension and milk recording results in an overall SCC reduction of 25% for the average herd. Farmers who undertook agricultural training were ten times more likely to monitor milk quality through milk recording compared to those who had not. Additionally, those farmers in contact with an extension service and also participated in a dairy discussion group were seven times more likely to practice milk recording. Practical Implications: The importance of farmer behaviour in the optimum management of herd health has been validated, as has the role of agricultural education and extension in influencing the uptake of best practice by farmers. Originality/Value: To date little research has been conducted using nationally representative herd-level data on the role of agricultural education and extension in improving animal health best practice.