In the search for alternatives to the intensive use of antibiotics in poultry farming, glycerides seem very promising. In a recent trial a combination of glyceride-based additives for feed and drinking water was successful in replacing the preventive use of antibiotics in broilers. Broilers were able to maintain growth performance and health status and even showed an improved immune response.
For years feed antibiotics were the number one in combating infections and intestinal disorders that are inevitable in the industrial poultry industry. They significantly improved weight gain, feed conversion and increased safety of the poultry population. However, concerns rise about pathogens becoming resistant to different types of antibiotics and antibacterial therapeutic agents. Therefore, it is of urgent matter to look for new supplements that help optimize animal health and performance and improve the safety and productivity of poultry.
KEY ROLE FOR GLYCERIDES
In their attempts to produce broiler diets without preventive antibiotics feed manufacturers have been applying conventional organic acids, and later also medium-chain fatty acids, for a long time. Which is not surprising as the mode of action of these acids has long been known and their effectiveness to support growth performance and gut health in broilers is extensively demonstrated in practice. However, new information reveals that the same organic and medium-chain fatty acids can be used much more efficiently. Even more, in the form of ‘glycerides’ they could play a key role when it comes to replacing preventive antibiotics in poultry farming. How? Let’s take a closer look at these glycerides.
Figure 1. Creating glycerides, like alpha-monoglyceride, 1,3-diglyceride and triglyceride.
WHAT ARE GLYCERIDES?
Glycerides are special molecules produced by Adisseo NL (formerly FRAmelco) in which a short or medium chain fatty acid is linked to a glycerol backbone, see Figure 1. The molecule that is created this way has special properties that are very useful to the bird. In contrast to conventional short chain and medium chain fatty acids, glycerides are pH independent and less susceptible to enzymatic breakdown, allowing them to be active throughout the entire gastrointestinal tract. These unique properties make glyceride-based products highly efficient. Scientific research has proven that glycerides indeed have a much stronger antimicrobial effect compared to their ‘free’ counterparts. Moreover, specific glycerides like those of lauric acid, are known for their potential anti-viral, immune-modulating and anti-inflammatory effects. And the good news is: the occurrence of resistance against these glycerides is very unlikely as supported by science.
Figure 2. FRA® C12 Dry improves the immune response in Infectious Bronchitis vaccinated broilers (De Gussem et al., 2021).
C12 in the spotlights
A special role is reserved for glycerides of lauric acid (C12), available as the feed additive FRA® C12 Dry. Find out the three reasons why the glycerides of this specific medium chain fatty acid support broilers’ natural immunity.
1. Antipathogenic effect as first line of defense
Next to their proven antibacterial properties, lauric acid glycerides possess antiviral properties against fat enveloped viruses as shown by in vitro studies. They are found to affect the viral fat-envelope, causing leakage and at higher concentrations a complete breakdown of viral particles.
2. Reduction of the inflammatory response
Lauric acid glycerides also reduce the expression of pro-inflammatory cytokines thereby avoiding overreactions of the immune system when small challenges occur. In this way broilers are able to save more energy for growth. However, in case of viral challenges, an increase of for instance interferon-gamma (IFN-γ) has been observed. This is important as IFN-γ is involved in inhibition of viruses.
3. Boost vaccination strategy
Moreover, according to a new study published in Journal of Applied Poultry Research, glycerides of lauric acid also stimulates the immune response of broilers after vaccination against Infectious Bronchitis, one of the most important diseases in the poultry industry today. Significantly higher amounts of antibodies were found in birds receiving FRA® C12 Dry compared to the vaccinated control birds, see Figure 2. Together with the observation that more birds were able to establish faster clearance of vaccine-derived IBV, this may suggest that lauric acid glycerides strengthen the immune response. The authors point out that the higher number of antibodies found in the animals receiving FRA® C12 Dry in their feed may result in better protection against future infections.
COMBINED APPROACH
Depending on the chain length of the fatty acid different glycerides can be obtained, each with their own affinity for certain pathogens. Glycerides of short chain fatty acids such as propionic (C3) and butyric acid (C4) are mainly active against Gram-negative bacteria. In contrast, glycerides of medium chain fatty acids like capric (C10) and lauric acid (C12) are more efficient against Gram-positive bacteria. They are mostly used in blends because of the intended synergistic effect, as described by literature. This combined approach of non-antibiotic supplements could be strong enough to effectively replace the preventive usage of antibiotics.
PROVEN IN PRACTICE
To test this combined approach a trial was conducted at a commercial broiler farm (Ross 308). Broilers in the control group got the full spectrum of antibiotics: at the hatchery they were injected with ceftiofur, via the drinking water they received enrofloxacin, colistin, trimethoprim (day 1 to 5) and ciprofloxacin (day 18 to 21) and via the feed they were given spectinomycin, lincomycin (day 0 to 9) and virginiamycin (whole period). To replace this intensive use of antibiotics, a specific program has been designed with a combination of three glyceride-based products: FRA® C12 Dry and FRA® Butyrin Ultra Dry in the diet and FRA® AC34 Liquid via drinking water.
Comparable growth performance
Results show that this strong combination was able to compete with the intensive use of antibiotics: broilers without any antibiotic performed evenly well as the control group. No differences were found between the control and treatment group regarding survival rate, feed conversion ratio and EPEF. They even showed an improved daily weight gain of 1.3%.
Figure 3. Blood serum antibody titer value against Newcastle Disease (ND) at day 22 and day 40 of life for the control group (preventive antibiotics; AGPs) and treatment group (FRA® glyceride combination).
Comparable health status
Also antibody titer values against Newcastle Disease (Figure 3), Infectious Bronchitis Virus and Infectious Bursal Disease Virus (also known as Gumboro disease) were higher for the treatment group, suggesting an immunostimulating effect of glycerides. Essential blood parameters, intestinal morphology and microbiota as well as development of intestinal lymphoid tissue, cecal tonsils and pancreas were comparable between both groups, indicating that broilers receiving a combination of FRA® products without antibiotics were well developed and able to maintain a good health status.
CONCLUSIONS
Compared to conventional organic acids and medium chain fatty acids, their glycerides are much more effective in supporting broiler performance, health status and natural immunity. This is mainly due to their unique molecular structure and is probably the reason that they are gaining popularity in broiler farming.
The results from this study indicate that a strong combination of FRA® glyceride products is able to replace the preventive use of antibiotics provided via the feed and drinking water without compromising animal health and performance. Broilers even showed an improved immune response as shown by the higher number of antibodies against typical poultry diseases. This possibly provides better protection in case a viral challenge occurs.
Data in this article is based on our current knowledge and experience. Since many factors can affect the performance of our products during and after application, processors are responsible for conducting their own tests and investigations. Certain statements may not apply in all geographic regions. For specific advice please contact Adisseo NL.
