Can strategies based on botanicals help piglets grow in the absence of zinc oxide?

Benedetta Tugnoli, a researcher at the Italian company, gave a talk at EuroTier on the work done by the firm to date to identify new tools, based on botanicals, to help piglets grow in the absence of therapeutic doses of ZnO.

Weaning stress often results in an impairment of the gastrointestinal tract (GIT) and the overall health of piglets, with the consequent onset of post-weaning diarrhea (PWD). Historically, PWD has been efficiently prevented due to the use of high doses of ZnO. Such doses, ranging from 1000 to 3000 ppm in the feed, controlled ETEC infections by exerting a mild antibacterial action and reducing PWD symptoms through enhancement of the intestinal mucosa’s overall health.

However, pharmacological doses of ZnO are no longer allowed in the EU.

The Vetagro team has been exploring the benefits of thymol, the key constituent of thyme essential oil, among other plant extracts, spices, and nature identical compounds, as alternatives.

Essentially it comes down to how effective botanical blends are at controlling control enterotoxigenic Escherichia coli (ETEC), the pathogen that is largely responsible for the onset of PWD in piglets.

Tugnoli and colleagues have been using intestinal models to determine this in-vitro​, as well as carrying out in-vivo​ testing, running experiments under both normal and challenged conditions.

The work done to date indicates that botanicals can target E. coli K88, through both direct antimicrobial action and through modulation of bacterial virulence, even at low doses, she said.

The Vetagro team has been collaborating with the University of Bologna in this respect, with their joint studies indicating that thymol has the capacity to control ETEC ​​growth, and that thymol and vanillin enhance porcine intestinal barrier function through the stimulation of the local immune response.

In summary, said Tugnoli, botanicals appear to enhance intestinal mucosa, they increase barrier integrity and reduce E. coli K88 translocation.

Microencapsulation ​

Vetagro is now working on fine-tuning its long-established microencapsulation technology to deliver the beneficial properties of botanical blends in vivo.​ 

“We currently have a botanical blend prototype, a combination of plant derived and synthetic compounds, and we are testing it in vivo in different markets, in Europe and the US, working to ensure the efficacy of the product,”​ Tugnoli told us.

“Our approach is always to move step by step, working with smaller research centers or universities with a low number of animals to prove the mode of action in vivo of a product that has been verified in the lab. Then we expand, testing it in bigger facilities, with a larger number of animals, and that is the stage we are at right now,” ​said the R&D specialist.

Vetagro has a history of working with nature identical compounds, prizing the control they allow in terms of stability. “However, we know from our work that plant mixtures bring some advantages, in terms of the opportunity to have a variety of active principals within a blend, and to maximize the biological interactions between different properties. With plant extracts you need to ensure there is consistency though, that for specification purposes, 15% of thymol, for example, is present in each batch of the product.”​

The work continues; a launch date for the botanical blend targeted at piglets has not yet been confirmed.