Farm Table says:
What is the problem?
A new Mycobacterium avium subsp. paratuberculosis (MAP) killed vaccine, for Johnes disease in cattle, was tested for effects on faecal shedding and milk production. The authors, from the Department of Animal Health in Spain, implemented a vaccine program on 4 farms, with 2 controls, and wanted to measure the epidemiological efficacy via bacterial shedding in faeces and the effects on milk production.
What did the research involve?
Six Holstein-Fresian herds in Basque Country, Spain, with clinical histories of Johnes disease were used. 2 herds were not vaccinated and used as controls. All cows and replacement heifers were vaccinated immediately after joining the vaccination program. Milk production records 5 years pre- and post- vaccination were used to calculate changes in milk production, and faecal samples collected. MAP was detected using both PCR and faecal culturing.
What were the key findings?
For 5 herds, faecal detection (n = 1829) and milking records (n = 2413) have been analysed after two years, and 1 herd, 4 years, from the beginning of the intervention. The prevalence of shedding was reduced by 100% in three of the four vaccinated farms, 68% of the total of vaccinated animals, and in the control farms, by 46%. The amount of MAP shed was reduced by 77% in the vaccinated farms and 94% in the control farms. Milk production increased up to 3.9% with vaccination, while there was no significant difference in production in the non-vaccinated farms.
Reduction of MAP shedding can be quickly accomplished both by vaccination and the traditional methods of testing and culling. The authors state that vaccination appears to be a less expensive and more sustainable option for control since it requires one single intervention, plus a milk production increase was seen.