An international audience of 150 vets and scientists recently attended a symposium on the topic of transition cow immunity, courtesy of Elanco Animal Health. The event took place in Vienna on 5th and 6th of November. At the event, six professors from Germany, Poland, Israel, the UK and US presented the latest thinking on how immunity, in particular innate immunity, is compromised during the vital 90 days (60 days pre and 30 days post calving).
Professor Holm Zerbe opened the event by highlighting the challenges presented by transition as the cow switches from immunotolerance of the foetus as an ‘antigen’, to development of a pro-inflammatory state after parturition as the immune system goes into a ‘full power decontamination’.
In particular, the rise in BHBA (betahydroxybutyrate) levels around transition due to the high energy demands and reduced energy supply is associated with profound effects on neutrophils, such as reduced phagocytosis and impaired chemotactic migration. The speakers described the way in which fat metabolism, inflammation and immune function are interlinked and how the picture during the ‘vital 90 days’ is far from a simple effect triggered purely by negative energy balance.
Live topics included a rationale for the different presentations of mastitis caused by E. coli and S. aureus, with specific differences attributed to inappropriate calibration of the innate immune response to these pathogens and cytokine expression.
The importance of neutrophils and the significance of mechanisms of action were discussed by Professor James Roth from the US and Professor Shpigel from Israel, using some powerful imagery including animation and electron microscopy of the phenomenon of NETS (neutrophil extracellular traps) – a possible newly identified mechanism by which neutrophils might control pathogens.
Scientists and veterinarians enjoyed discussing their own perspectives on immunity at a series of informal dinners. This merging of viewpoints regarding practical applications and ground breaking research proved to be highly successful and an interactive roundtable at the end of the day’s proceedings resulted in an impressive 132 questions being submitted for discussion. It’s clear that veterinarians saw enormous opportunities to improve dairy cow health and production emerging as a result of improved understanding of the mechanics of immunity.