Salmonella control: Ceva has good news for poultry farmers
A new age is dawning in food safety with the introduction of Layermune SE (G3788 act 36/1947), a valuable tool for salmonella control.
Layermune SE is the first and most thoroughly tested United States Department of Agriculture approved Salmonella enteritidis bacterin for chickens.
Data collected by independent researchers in controlled laboratory studies and through actual field use of Layermune SE in the USA, Latin America, Europe and Asia demonstrate the value of the killed salmonella vaccine (bacterin) in reducing salmonella in breeders, broilers and commercial laying hens.
Layermune SE stimulates the chicken’s immune system to reduce salmonella colonisation in internal organs and the intestines.
Layermune SE has been proven successful for millions of chickens around the world against vertical and horizontal transmission of salmonellae by providing the following benefits:
1. Aids in the prevention of salmonella colonisation of chickens in an SE positive environment
2. Reduction of colonisation of the internal organs to prevent ovarian transmission to the egg
3. Reduction of colonisation of the intestinal tract to prevent faecal shed to
- the hatching egg, thereby reducing salmonella positive chicks
- the environment, reducing contamination
4. Pass maternal antibodies to progeny to prevent colonisation during the most susceptible first two weeks of age
5. Cross-protection against salmonella species of heterologous SE phage types, serotypes within the same serogroup and partial protection across serogroups
Laboratory trails demonstrate the efficacy of Layermune SE
Reduction of SE colonisation in internal organs and intestines
Immunogenicity studies were conducted in chickens vaccinated with Layermune SE. In all trials, two 0,5 ml injections four weeks apart of Layermune SE were subcutaneously administered according to label directions.
Unless otherwise indicated, chickens were orally challenged with a pathogenic SE obtained from egg contents at a dose of 3×108 CFU (300 million colony forming units), a challenge dose far greater than would be encountered in nature. The oral route of challenge was chosen to simulate a natural exposure.
Non-vaccinated hens serving as controls and vaccinated hens were simultaneously challenged.
Cultures of internal organs (liver, spleen, ovary and oviduct) and the intestines were made to determine the number of hens positive for SE colonisation in any tissue following challenge.
Protection was defined by failure to re-isolate SE.
*Statistically significant difference between vaccinates and controls at p<0,05]
Results from these studies demonstrated that Layermune SE provided excellent protection against infection by SE of internal organs, including the target organs of the reproductive tract (Figure 1).
This protection was statistically significant at p<0,05. The data also demonstrated an age resistance to challenge.
It has been scientifically acknowledged that protection of internal organs, specifically the reproductive tract, reduces the risk of ovarian (vertical) transmission of salmonella to chicks or shell eggs.
*Statistically significant difference between vaccinates and controls at p<0,05]
Layermune SE provided excellent protection (p<0,05) to the intestine against colonisation by SE (Figure 2). Unlike internal organs, there was no age resistance to challenge evident in intestinal colonisation.
In a study evaluating SE contamination of the egg shell surface, faecal shed of SE from vaccinated hens was significantly less compared to non-vaccinated hens for a 14 day period following oral challenge (Figure 3).
This unique ability of Layermune SE to reduce salmonella colonisation of the intestine reduces faecal shed and contamination of eggs, thereby reducing salmonella positive eggs and chicks as well as salmonella excretion into the environment.
Maternal antibody protection
Another defence mechanism provided by Layermune SE is maternal antibody protection conferred to progeny of vaccinated breeders. These maternal antibodies protect chicks during their most susceptible first two weeks of age against colonisation by salmonellae.
a. S. enteritides phage type 4
b. S. typhimurium
c. S. pullorum
Source: Ohta, H 1998]