Modern poultry production allowed to increase the productivity at the farm level. As a consequence, a higher susceptibility of the birds to different bacterial or viral diseases in the poultry houses due to changing conditions like the concentration of the birds, multi-age sites, increased genetic potential but more fragile birds.
Biosecurity and farm management are the basics to limit the effects of this higher susceptibility. Vaccination is helpful to prevent diseases and antibiotic treatment to cure the birds in case of diseases.Increasing the vaccination efficacity is key as antibiotics need to be used cautiously.
Make the vaccinations more efficacious: help the adaptive immune system
To guarantee an optimal efficacy of the vaccination, several parameters need to be taken into account:
- Vaccinate birds only when they are in good health
- Use a vaccine with the proper strain against a pathogenic viral or bacterial strain. Very often there is no cross protection between these different strains
- One bird, one dose
- Respect the good route of administration for live vaccines: a digestive virus must be applied by drinking water and a respiratory virus must be applied by spray or eye-drop.
- Respect the good mode of administration: each vaccine supplier should give a check list with the different points to follow: preparation of the vaccine solution, preparation of the birds, etc…
We can also use a potentiator to increase the level of the vaccine response, resulting in a higher level of antibodies. A good potentiator, interesting to be used around a vaccination, is Safmannan®.
Safmannan®, a premium yeast fraction, supplied by Phileo, contains β-glucans and mannans which activate different receptors (dectins, TLRs, Galectins) at the surface of important immune cells (dentritic cells and macrophages). This interaction enables a faster reaction of the adaptive immune system against a pathogen or a vaccine (whichisin fact an attenuated pathogen).
Resulting, for instance, in a higher vaccine response on birds vaccinated against Newcastle disease (see graph 1). Several trials have demonstrated this effect. Gomez-Verduzco et al. vaccinated broilers with a live Newcastle disease vaccine at 10 days. Blood tests were taken 1 and 2 weeks after the vaccination. The serology method used was the Haemagglutination Inhibition test. The group fed with a feed supplemented with Safmannan® showed a significantly higher antibody response 2 weeks after vaccination.
Graph 1: Higher vaccine response on birds with Safmannan® (Gomez-Verduzco et al., 2009)
Another trial was done in 2016 (S. V. Rama Rao et al., unpublished) on broilers challenged with natural heat stress (maximum temperature reaching at least 35°C every day in the shed till 42 days). The birds were vaccinated with a Newcastle live vaccine (La Sota) at 7 and 28 days old (see graph 2).
Graph 2: Higher vaccine response at 42 days on birds with Safmannan® in heat stress conditions (S. V. Rama Rao et al., 2016)
Even in heat stress conditions, a good vaccine response on broilers vaccinated against Newcastle disease was monitored. At 21 days, no difference was shown in the blood samples. The vaccination at day 7 was applied to result in a competitive exclusion against a potential wild virus. At this age, the objective is not to produce a high quantity of antibodies. The booster vaccination at 28 days enables the production of antibodies by the birds in high quantity. At 42 days, tests showed a significant higher antibody level thanks to the incorporation of Safmannan® in the feed.
Raise the barriers of the innate immune system
Helping the adaptive immune system to be more efficacious after vaccination is a specific reaction associated with a non-specific one, called innate immunity. Whatever the pathogen contaminating the birds, the innate immunity will fight against it with the same defense lines:
1. First defense line:
- Physical barriers: skin, epithelium, tight junction, mucus on epithelial cells,tracheaciliarflutter,gutperistaltism, …
- Chemical barriers: fatty acids,lyzozym,proventriculepH acidity, antibacterial peptides (Paneth cells), …
- Microbiologic barriers: normal gut flora, competition against pathogen and bacteriocins
2. Second defense line:
- Phagocytes, able to eliminate bacteria opsonized by the complement system
- Mast cells, able to “wake up” the immune system in case of an infection
- Natural Killer cells, able to kill directlyvirus infectedcells or tumoral cells
As 70% of the bird’s immune system capacity is located in the digestive tract, it is important to preserve a good gut integrity. The chronic intestinal inflammation, due to the high feed intake of modern poultry breeds, needs to be controlled.
Safmannan® helps the innate immune system to be better prepared against an infection by:
- Pathogen binding (E.coli, Salmonella enterica, Clostridium perfringens) decreasing the pressure of these bacteria in the intestinal tract.
- Increased goblet cells number, creating a better epithelial cells barrier with a thicker mucus layer protecting the epithelium of the gut.
- Decreasing at certain dosage particular pro-inflammatory cytokines release (IL-6) (Zhang et al., 2008). In case of a non exaggerated inflammation: limit the chronic inflammation due to high feed intake, which is the « ugly » part of the innate immunity. And less inflammation means preservation of the tight junctions: no translocation of pathogens from the gut to the organs (E.coli, Enterococcus…)
Feed needs to contain the necessary building blocks for birds to build an efficacious immune system; especially when grown in stressful conditions. The association of the adaptive and the innate immunity is most of the times strong enough to prevent diseases. Safmannan® helps this system to be faster and stronger.
- Gomez-Verduzco et al., Acta Veterinaria Scandinavica, 2009, 51:11
- S. V. Rama Rao et al., unpublished, 2016
- Zhang et al., Asian-Aust. J. Anim. Sci., 2008, 21(2):237-244