Growing confidence in

Developing new ways to prevent or alleviate an infection in livestock is a tricky business – not least because many pathogens live within their host animal, creating a physical barrier between them and the outside world.

However, recent scientific developments have led to the ability to grow organs in the lab. Researchers at the Moredun Research Institute (MRI) have been successfully growing mini cow and sheep stomachs and intestines and they are now using them to understand how certain livestock pathogens interact with the specific and relevant tissues.

It doesn’t stop there, either. Having gained success with their ministomachs and miniintestines, the researchers are also actively focusing their attention on growing other miniature organs, such as brain, lungs, tonsils and lymph nodes, that represent important sites of infection for many of the pathogens we are interested in protecting our livestock against, as well as expanding on the range of animal species from which we can grow these miniature organs.

For example, by using mini-stomachs to help understanding of how parasites survive inside cattle, scientists at MRI and the Roslin Institute, have joined forces to develop threedimensional cell cultures which mimic the stomach of cattle.

These “mini-stomachs’” are being used to form a detailed analysis of how the worms interact with the cells lining the stomach, and to test the effects of anthelmintic drugs on worms when they are within the stomach environment.

Ostertagia ostertagi is gastrointestinal worm parasite which affects millions of cattle globally and is highly prevalent in the UK.

In a recent UK abattoir survey, 89% of cattle had evidence of infection by this parasite, which lives in the abomasum (or true stomach) of cattle where it causes losses in calf growth-rates, carcass quality and milk production.

Control of this parasite relies heavily on anthelmintic drug treatments. Worryingly, there is now good evidence that the parasite is becoming resistant to many of these drugs, meaning existing treatments are becoming less effective.

Therefore, the industry will need new methods of parasite control. This could involve interfering with the parasites ability to suppress immune responses to allow cattle to control the parasite more quickly, or developing new types of anti-parasite drugs.