Introduction

Eggs have great nutritional value, however, it is also one of the main foods causing food poisoning, especially by Salmonella spp. The pathogenic microbial load present in the digestive tract of birds is related to the presence of pathogens in the egg, which can negatively impact food safety.

The cimenol ring has a bactericidal and fungicidal effect that can control the presence of pathogenic microorganisms in the intestine, which reduces the microbiological contamination of the egg. In the trial below, this effect is compared with other products such as organic acids or formaldehyde.

Objective

The trial lasted for 15 weeks and started with 15-week-old layers. It included the last period of the rearing phase, corresponding to the first three weeks of the trial, and a laying phase that began at week 18 of age. A total of 224 pullets (Dekalb Brown) were used, divided into the following experimental groups:

1. Control: standard basal diet (SBD), no antimicrobials and no additional treatments for Salmonella spp.
2. Alquermold: SBD + cimenol ring (0.5 kg/t), continuous administration.
3. Organic acids: SBD + organic acids* (1 kg/t), continuous administration
4. Formaldehyde: SBD + formaldehyde at 33%** (2 kg/t), continuous administration

*Orthophosphoric 53%, citric 15%, acetic 5.25%, 15% fumaric, tartaric 1.75%, propylene glycol 1%
**Formaldehyde at 33% and propionic acid at 9%

The percentage of dirty egg was evaluated in the four experimental groups. Microbiological analysis of the eggs, cloacal swabs and intestinal tract of birds was performed to assess the degree of bacterial contamination in each group.

Results

The percentage of dirty eggs obtained was 12.15% in the group supplemented with formaldehyde, 6.64% in the group with organic acids, and only 2.29% in the group supplemented with cimenol ring (figure 1). Cimenol ring reduced the percentage of dirty eggs by 55.79% compared to organic acids, by 65.51% compared to the control group and by 81.15% compared to the group supplemented with formaldehyde.

The microbial load present in the egg, faeces, cloacal swabs and intestinal content was assessed in the four experimental groups. In the case of eggs, the presence of E. coli and Campylobacter sp. was observed in the group supplemented with formaldehyde and in the control group. In the case of organic acids, the presence of Campylobacter sp. was not observed, however, the presence of E. coli was detected at the peak of laying. Unlike the other experimental groups, in the group supplemented with cimenol ring, those microorganisms were not observed (table 1 and 2).

Regarding the cloacal swabs, Clostridium perfringens (table 3) was observed in all groups except for the one with cimenol ring. Results showed how the cimenol ring reduces by 92.3% the presence of E. coli compared to the control group. Organic acids and formaldehyde provide intermediate control of E. coli with a reduction of 50.8% and 53.8% compared to the control group (figure 2).

The presence of Clostridium spp., E. coli and Campylobacter sp. was evaluated in the intestine. In all cases, the group supplemented with cimenol ring was the one with the lowest counts. For Clostridium perfringens, the reduction was of 100% in the case of the cimenol ring, while, in the rest of the groups, the presence of this microorganism was found (table 4 and 5).

In the case of Campylobacter sp., the cimenol-ring group achieves a 96% reduction in the number of CFUs, while organic acids achieve a reduction of 38.27%, and formaldehyde of 40.47%, compared to the control in week 29 of age. Formaldehyde initially reduced the presence of this microorganism, but its effect did not last throughout the test and the count of this microorganism increased at the end of the laying period (table 6).

Conclusion

Food safety, which means the availability of safe, nutritious and innocuous foods, is one of the factors of greatest concern for consumers.

The use of the cimenol ring allows to obtain lower microbiological contamination in both eggs and animals. It reduces the presence of E. coli by 92.6% in cloacal swabs, Campylobacter by 96% in intestinal content, as well as Clostridium perfringens by 100% at the intestinal level.

This way, thanks to the control of the intestinal flora, the cimenol ring significantly reduces the percentage of dirty egg.

The cimenol ring is marketed under the name Alquermold Natural by Biovet S.A.