Synergistic feed additive strategy to reduce antimicrobials

As most of a broiler’s immune cells reside in the gut in the form of GALT (gut associated lymphoid tissue), maintaining a healthy gut is critical to supporting broiler health. Research shows that an integrated 4-pronged strategy (Figure 1) leveraging the relationship between nutrition and microbiology, immunology and physiology can help to improve and maintain gut health while reducing the use of antimicrobials.

Figure 1 – 4 pillars help support gut health.

Combined with sound feed and farm management, a health management programme will help producers consistently achieve successful flocks while reducing the need for antimicrobials. In addition, the vaccination programme should be carefully customised and applied correctly, with antibiotics used responsibly: as little as possible and as much as needed, based on antibiograms.

A synergistic approach leverages different feed additives as part of a 4-pronged gut health strategy to support broiler health while reducing or removing antibiotics.

• Step 1: Special blends of organic acids can reduce the pH in the crop and proventriculus to levels where many pathogenic bacteria struggle to survive, while also supporting digestion.
• Step 2: Specially-developed feed additives can strengthen the gut barrier function and balance the microbiota.
• Step 3: Specific ingredients can help immunemodulation, directly and by contributing to a healthier gastrointestinal tract.

Synergistic combination explained

Supplementing feed with Selko Presan-FY and Selko IntelliBond C is a proven and promising synergistic approach to an AGP-free production system.

Presan-FY and IntelliBond C focus on 2 aspects of gut health:

1. strengthening the gut barrier function and microbiota stabilisation,
2. while improving gut digestion and immune modulation to achieve notable health and performance benefits.

A well-modulated gut supports a bird’s immune response when necessary, without triggering an immune system overreaction.

Managing multiple and complex challenges

The physiology of broiler gut integrity, its microbial community and immune systems, is complex and highly interactive. Enterocytes in the gut wall are connected through complex protein structures called tight junctions which maintain the barrier between intestinal cells. These tight junctions control which substances are allowed to translocate through the barrier, keeping valuable proteins on the correct sides of the cell wall for essential cell functions to occur.

The ingredients for Presan-FY are carefully selected to support the gut wall barrier. Presan-FY is a synergistic blend of phenolic compound, slow release C12, target release butyrates, medium-chain fatty acids (MCFA) and organic acids. Presan-FY supports the gut wall barrier and reduces total bacterial counts in the intestine, while supporting a varied and stable microbiota.

Microbes compete with host for nutrients

Microbial activity affects growth and efficiency as microbes inside the gut compete with the host for nutrients. A reduction in microbial activity in the intestine is the main suggested physiological process used to explain the effects of antibiotic growth promoters (AGPs) in improving animal performance.

Microbes decrease fat digestibility

Higher concentrations of intestinal microbes also decrease fat digestibility by deconjugating bile acids. This causes a decrease in lipid absorption and produces toxic metabolites that inhibit growth.

Undigested protein

Undigested protein bypassing the first part of the intestine can also serve as a food source for microbiota further down the intestinal tract. Toxic metabolites produced during this fermentation process can impact intestinal cell turnover and hinder growth performance. Immature or damaged enterocytes are more vulnerable to coccidiosis. In addition, goblet cells may produce too much mucus, hindering feed passage rate and nutrient absorption, resulting in a higher feed conversion ratio.

A varied, stable microbial community is directly related to better feed conversion ratios in both healthy and challenged broilers. Greater diversity in microbial genera has been associated with greater resilience and better production performance in broilers. Specific bacteria also have distinct functions in the gastrointestinal tract.

Impact of high levels of trace minerals on broilers

While the nutritional trace mineral requirements of broilers have long been known, researchers are studying how high levels of trace minerals affect mode of action in broilers, impacting performance as well as intestinal microbiota. Feeding a high concentration (125-225 ppm) of copper above nutritional levels has been shown to have strong antimicrobial effects in broilers in regions where regulations permit higher levels of copper to be fed. However, the mineral source is critical. Research suggests that crystalline structure of hydroxy copper and its strong covalent bonds, as in IntelliBond C, allow more copper to reach the hind gut and support the stabilisation of microbiota. This unique mineral structure also provides greater stability with sensitive feed ingredients, has more efficacy and supports better gut health and growth compared to sulphate and oxide sources.

Figure 2 – Increase in microbial diversity by Presan-FY and IntelliBond C in different segments of the gut.

Studies have further shown that a synergistic approach helps to improve gut health, thereby supporting optimum animal performance without the use of antimicrobials. The ingredients in Presan-FY, fed in conjunction with high levels of IntelliBond C, have been shown to reduce total microbial counts, increasing diversity in all segments of the gut (Figure 2), while enahancing the strength and stability of microbiota in the entire gastrointestinal tract.

Equal performance results as AGP

4 studies were conducted between 2017 and 2020 evaluating how the combination of Presan-FY and IntelliBond C impacts broiler growth performance and efficacy compared to AGPs.

They all compared 3 treatment diets:

1. A negative control with a standard commercial diet,
2. A positive control which included BMD or Zinc Bacitracin at 50-55 ppm, and
3. Presan-FY + IntelliBond C at high levels (125-225ppm).

The studies were conducted in 3 different regions of the world, thereby covering different production systems, climate and housing conditions. The findings showed that broiler performance results equal to AGPs can be achieved with ­Presan-FY + IntelliBond C (Figure 3).

Figure 3 – Relative broiler performance in four independent studies of Presan-FY + IntelliBond C compared to AGP (horizontal line indicates AGP performance results).

Consistent results

The research shows that an integrated 4-pronged strategy can support gut health. Feed formulation and dietary strategies which include the synergistic use of feed additives can help to improve gastrointestinal development and digestion, the absorption of nutrients and immunity. Controlled research has consistently shown that Presan-FY + IntelliBond C is an effective combination to improve broiler performance while reducing antimicrobials.