Milk ELISA test data provides practical and evidence-based goals for the National Johne's Management Plan

Phase 3 of the National Johne's Management Plan set an aspirational goal for the dairy industry in Great Britain to achieve a Johne's Control Index of ≤5.5 by 2030. The Index is defined as the mean of the annual average test values of all herds with available data in the National JD Tracker Database. The Johne's Control Index improved from 10.0 in 2015 to 6.71 in 2024. Herds have an increased likelihood of achieving an average test value ≤5.5 when %J4 (percentage of newly test-positive cows) is ≤1.0% and %J5 (percentage of repeat test-positive cows) is ≤1.25%. The likelihood of a herd having an average test value ≤5.5 in 2024 was also increased in herds which had demonstrated an average test value of ≤5.5 in previous years.