Can yeast biotechnologies ensure a reduction in antibiotic use in birds?

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Phileo Lesaffre says its yeast products can support layer and broiler farmers in their bid to reduce dependence on antibiotic use.

Alain Riggi, global poultry manager, at Phileo Lesaffre, spoke about the benefits of the company’s yeast biotechnologies at a symposium on antibiotic reduction strategies for pig and poultry industry it hosted last month in Rome.

Prevention was the overriding theme of the event, he said.

Delegates from all over the world heard that good farm management, a high level of biosecurity and good feed quality are essential to prevent physiological disorders and to make birds healthier, more resistant and therefore less likely to require antibiotics, he said.

Supplementation of poultry feed with particular yeast derivatives can benefit bird gut health and limit pathogenic bacteria, while supporting bird immunity and the vaccine response as well as feed quality, said Riggi.

Gut health 

Trial data, he said, show the company’s yeast fraction – Safmannan – and its yeast extract – Nucleosaf – reinforce bird gut health by helping to maintain the absorption capacity of the gut. Other studies, he continued, indicate its selenium enriched yeast product, Selsaf, improves resistance to oxidative stress in poultry.

“We are producing these products especially for the effects they have on poultry. They are premium products, with consistent results. They are not by-products of the food industry.”​

Its Safmannan product is rich in mannan-oligosaccharides and beta glucans, and inhibits the development of an environment for pathogenic bacteria to reside in the gut, he explained.

“It has the ability to bind gram negative bacteria like E.coli, Salmonella and gram positive bacteria like Clostridium. It can decrease the pressure of the bacteria in the gut by two to three logs.”​

Due to its high mannanoligosaccharides content, the product reduces the attachment of gram-negative bacteria onto the intestinal epithelium, he said. “Fimbriae of bacterial cells are sensitive to mannose. Hence, Safmannan is able to bind these pathogens. The bacteria is, thus, excreted through the feces into the litter.”​

Mode of action under review ​

However, he told FeedNavigator the company only has a hypothesis, at this stage, about the mode of action in terms of how Safmannan binds Clostridium. “We are working with bacteria and mycotoxin binding experts at universities in Mississippi in the US and in Bari in Italy to explain it. The researchers have developed methods and tools to assess the binding ability of products.”​

Along with the in vitro research examining the binding properties of the yeast cell product, Riggi said the company has also been evaluating Safmannan using in vivo Clostridium​ challenge trials. “We work with Texas A&M in College Station, Texas and the Virginia Diversified Research Institute, also based in the US, to do this. They have developed Clostridium challenge models [based on corn-based diets]. We challenge the birds with and without our product in the feed and we follow the birds regarding performance, morality, and lesion scores in the gut.​

“The challenge is really drastic. They challenge the bird with a coccidiosis vaccine first to have a disorder in the gut; then they introduce a highly pathogenic strain of Clostridium – a high dose over three days. We have at least, on a positive control, 10% or 12% mortality when we do this challenge.” ​

“On European farms, where there is often subclinical enteritis due to Clostridium, we see problems such as wet litters and liquid feces, and so on. When we add Safmannan [in the feed] on those farms, we have less wet litter in the pens, and better transition from starter to grower feed.”​

He said trials have shown that, when comparing it with antibiotic growth promoters such as Avilamycine, the yeast cell wall product delivered the same performance in terms of body weight gain and FCR.

“Yeast biotechnologies are not alternatives to antibiotic growth promoters because the mode of action is different but the effect ​on the growth performance is, at least, the same.”​

Vaccine management​

Safmannan also has the capacity to directly interact and improve a bird’s immune system and the vaccine response, bearing in mind, that producers choose the right vaccine strain, ensure correct vaccine storage and quality of administration, he said.

“Along with mannans, our product contains, at least 20% beta glucans. They will interact with the bird’s immune system.”​

He said beta-glucans are recognized by different receptors on the surface of important immune cells, such as dendritic cells and the macrophages (Perez-Garcia et al., 2011). This recognition enables a faster reaction of the adaptive immune system against a pathogen. 

“Gomez-Verduzco et al. vaccinated broilers with a live Newcastle disease vaccine at 10 days, and did blood tests, one and two weeks after the vaccination. The serology method used to assess the impact of Safmannan was the Haemagglutination Inhibition (HI) test and a significantly higher antibody response was obtained two weeks after the vaccination (at 24 days), on the group fed with a Safmannan supplemented feed.”​