Avian infectious bursitis, or Gumboro disease (IBD), is a highly contagious viral pathology characterized by infection of the bursa of Fabricius, immunosuppression and nephritis-nephrosis. It is caused by a birnavirus that causes high morbidity and mortality.

Avian infectious bronchitis (IBV) is also a viral pathology characterized by respiratory symptoms, kidney injuries and altered egg production in laying hens. It is a disease caused by a coronavirus, which affects birds from 4 weeks of life.

Newcastle disease (ND) is a highly contagious virosis caused by a paramixovirus. It is characterized by a diphtherial haemorrhagic injuries throughout the digestive tract, along with a nervous symptomatology, as well as embryonic mortality in infected eggs, resulting in high morbidity and mortality.

Infections by the three viruses mentioned cause immunosuppression and, therefore, these viruses act as a gateway for other pathogens.

Immunostimulant pronutrients are active molecules of botanical origin able to improve vaccine response and increase both cellular and humoral immunity.

1. Objective

Evaluate the effect of immunostimulant pronutrients on the vaccine response against IBD, IBV and ND during breeding.

2. Material and methods

The study was conducted with Hy-Line W-36 laying hens to evaluate the antibody titers. Two experimental groups were used:

• Control group: 67417 1-day-old chicks vaccinated without immunostimulant
• Pronutrient group: 71176 1-day-old chicks, vaccinated and with immunostimulant pronutrients in the feed at doses of 0.5 kg/t, from day 39 to day 96 of life.

The trial lasted 96 days and the vaccination protocol used is described below:

3. Results

3.1 Antibody titers

Antibody titers for all three diseases were evaluated. Higher antibody titers were observed in the group treated with immunostimulant pronutrients, especially against IBD and NC, where the antibody titers were a 25% and a 51% higher, respectively.

In the case of IBV the increase was of 4%, however, we must have in mind that the titers of antibodies against the disease was significantly lower in the pronutrient group compared to the control group, at the beginning of the trial.

3.2 Flock culling and mortality

Both the percentage of flock culling and the cumulative mortality rate during the trial were lower in the immunostimulant group.

3.3 Homogeneity and weight

No significant differences were observed in relation to these two production parameters. However, the percentage of homogeneity was more stable throughout the trial in the group treated with immunostimulant pronutrients.

4. Conclusion

The addition of immunostimulant pronutrients in the feed in rearing birds allows to enhance the vaccine immunity, increasing the antibody titers, against viral diseases such as Gumboro disease (IBD), infectious bronchitis (IB) and Newcastle disease (ND). At the same time, it allows to reduce discards and accumulated mortality.

Immunostimulant pronutrients are marketed under the name Alquernat Immuplus of Biovet S.A.