Salmonella spp. is still one of the leading causes of foodborne infections in the world, mainly due to the consumption of food prepared from infected poultry meat and eggs.
The antimicrobial effects of organic acids and essential oils (EO) have been scientifically proven (Hammer et al., 1999). Their mode of action of the EO is to increase the bacterial cell membrane permeability. This enhances the efficacy of organic acids, by damaging the pathogenic cell membrane structure, which effects its functions and leads to death of the microorganisms. After easy penetration into the Salmonella cell, the normal cell physiology is disrupted (reduction of intracellular pH and anion accumulation), resulting in cell death. Both short chain fatty acids (SCFA) and EO can act as an antimicrobial only if they come in contact with the bacteria in active form. It has been shown that feed supplementation with mixtures of SCFA alone or in combination with EO and coated on a carrier results in decreased intestinal colonization, mortality and morbidity after Salmonella infection.
Kemin research showed that encapsulation techniques are valid tools to increase SCFA and EO efficacy along the gastrointestinal tract versus non-encapsulated options.
A trial was conducted to evaluate the ability of FormaXOL™, applied as a prevention programme starting from 1 day-old chicks, to reduce Salmonella spread between birds.
Experimental animals and treatments. As hatched, one day old specific pathogen free (SPF) broiler chicks were randomly divided into 2 groups (Control and FormaXOL™ 1.00) of 25 chicks each. Birds of the control group received non supplemented commercial feed while the treated group received, from arrival, feed supplemented with 1000 ppm of FormaXOL™.
Infection and analysis. At 11 days of age, 10 broilers of each group were infected with 106 cfu of a strain of Salmonella enteritidis isolated from a commercial poultry farm. Immediately after the infection, 10 broilers of each group were re-placed in the original floor pan, together with the 15 non-infected broilers chickens.
At 40 days of age, 15 broilers of each group (5 from directly infected and 10 from non-infected birds) were euthanized by CO2. Salmonella analysis was performed on neck skin samples.
Table 1 shows the number of neck skin samples positive to Salmonella spp. at slaughtering (40 days of age or 29 days post infection). In the control group 6 out of 15 neck skin samples were positive to Salmonella, while the FormaXOL™
fed group had no Salmonella spp counts in the neck skin (p < 0.01). This could be due to the higher Salmonella prevalence in the control group, which is then able to contaminate the carcass. the FormaXOL™ groups, however, likely did not have a high enough prevalence of Salmonella to contaminate the carcass.
Table 1. Number of neck skin samples positive to Salmonella
The inclusion of FormaXOL™ at 1000 ppm, resulted in no Salmonella contamination in neck skin samples. FormaXOL™ was effective in infected birds as well as in the non-infected ones. The results demonstrate the efficacy of FormaXOL™ to both prevent the spread of Salmonella from infected to non-infected birds and to kill Salmonella or prevent its colonization in directly infected animals.
1. Kemin Internal Document TL-2010-00008
2. Kemin Internal Document TL-12-00063
3. Hammer K.A., Carson C.F., Riley T.V. (1999). Antimicrobial activity of essential oils and other plant extracts. Journal of Applied Microbiology 1999, 86, 985–990.