ANIMAL HEALTH IRELAND Contributing to a profitable and sustainable farming and agri-food sector through improved animal health


FACT SHEET Pasteurisation may be an option for providing an extra level of assurance for farmers actively managing the risk of Johne’s disease

Pasteurisation of milk and colostrum and Johne’s disease

P asteurisation is a process used in food processing to reduce the number of bacteria in a product to render it safer for consumption. The term is often associated with milk where pasteurisation has been used for more than 100 years to reduce the bacterial load and increase the shelf life. There are two types of pasteurisation that can be applied to milk. Commercial pasteurisation is a High Temperature Short Time (HTST) continuous process which heats milk to around 72 o C for 15-25 seconds. The second form of pasteurisation is Low Temperature Long Time (LTLT) batch pasteurisation where milk is heated to 60-65 o C for up to one hour. There is some evidence to suggest that MAP may be more sensitive to LTLT pasteurisation. Although either method may be used with milk, it is important to note that neither HTST pasteurisation, nor LTLT pasteurisation if carried out above 62 o C, are suitable for the pasteurisation of colostrum. Several studies have shown significant reductions in immunoglobulin levels and thickening and coagulation of colostrum when heated to temperatures of greater than 62 o C. Calves fed

colostrumheated to these temperatures are at increased risk of diarrhoea due to changes in the colostrum consistency and failure of passive transfer of colostral antibodies, leading to increased susceptibility to calf- hood diseases. Therefore, the current recommendation which is used in many of the purpose-built commercial colostrum pasteurisers is to heat colostrum to 60 o C for 60 minutes. Pasteurisers should be regarded as only one tool in the armoury

to control JD rather than a silver bullet; calf hygiene remains a crucial component of managing dairy calves, providing benefits beyond just control of Johne’s disease.

Johne's Control AnimalHealthIreland.ie

JOHNE’S DISEASE CONTROL PROGRAMME Animal Health Ireland, 4-5 The Archways, Carrick-on-Shannon, Co. Leitrim, N41WN27

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