Feeding chickens a “cocktail” of bacteriophages — viruses that infect and kill bacteria — can significantly reduce Salmonella in chickens and improve productivity, according to scientists.
Researchers from the University of Leicester have developed a product that prevents bacterial infection developing when it’s added to broiler feed.
It’s hoped the product, which targets multiple strains of Salmonella, will eventually be available for use in commercial poultry production to reduce the risk of the pathogen entering the human food chain.
In a paper published in the journal Emerging Microbes & Infections, the researchers said they separated 672 broilers into six groups, feeding them a standard diet or a phage diet of three varying strengths.
Groups were either challenged with Salmonella or left unchallenged.
After 42 days the scientists took faecal samples from the birds and found that even those treated with the lowest dose of phages had lower levels of Salmonella, even when they were challenged with the virus. Those given the highest dose performed best, they said.
What’s more, phage treatment across all doses had a positive impact on growth performance in challenged birds, with increased weight gains in comparison to challenged birds with no phage diet, the researchers wrote.
“We showed delivering phages via feed was effective at reducing Salmonella colonisation in chickens, and our study highlights phages offer a promising tool to target bacterial infections in poultry.
“Future research will focus on investigating safety of phage therapy by determining the impact of phages on the microbiome of chickens,” they added.
The role of phages in agriculture
Phages work by attaching to bacterial cells and injecting their genome into them, interfering with their ability to function. Because the bacterial cell is unable to reproduce, and instead produces additional phages, the bacteria is unable to cause infection.
Scientists hope phages’ ability to control bacteria could make them a good alternative to treating livestock with antibiotics — particularly in the face of growing antimicrobial resistance around the world.
They are effective in disease control because they self-replicate and self-limit, which means they only continue to replicate for as long as bacteria are present. They’ve also been shown to be non-toxic, showing no harm to consumers.
Phages are usually cheap and simple to prepare and store, making them a promising alternative to chemical controls — both in livestock and arable production systems.
