Porcine epidemic diarrhea (PED), is a viral disease, caused by an Alphacoronavirus, of the Coronaviridae family. PEDV is an RNA virus wrapped with a morbidity of 100%, a reduced mortality in adult animals (1-3%), but high in piglets reaching 100% in piglets under three weeks. It causes an acute gastrointestinal syndrome, with diarrhea, vomiting and dehydration, which subsides after 7-14 days. The disease is especially common in piglets from mothers not previously exposed to the virus and therefore without antibodies against it.

Vaccination is used as a preventive method, through the application of attenuated vaccines in breeding sows. The sows transmit s-IgA to the piglets through the colostrum, preventing the onset of the disease.

Immunostimulant pronutrients are active molecules of botanical origin capable of stimulating the immune system and boost the vaccine response.

1. Objective

The objective was to replace an additional vaccine administered orally (difficult administration) by immunostimulant pronutrients, to improve colostrum’s quality (s-IgA concentration) and, therefore, the piglets’protection against Porcine epidemic diarrhea (PED).

2. Material and methods

The following experimental groups were used to carry out the test:

1. Control group (15 sows): 2 vaccinations at 40- and 20-days pre-partum, attenuated vaccines administered intramuscularly.
2. Experimental group (15 sows): 2 vaccinations at 40-and 20-days pre-partum, attenuated vaccines administered intramuscularly together with immunostimulant pronutrients at dose of 0.5 kg/t.
3. Extra vaccine group (11 sows): 3 vaccinations, 2 vaccinations at 40-and 20 days pre-partum days, attenuated vaccines administered intramuscularly and a third vaccination at 15 days pre-partum, attenuated vaccine administered

In order to analyze the amount of immunoglobulins (IgA) transferred through the colostrum in the three experimental groups, colostrum samples were taken on the first day after birth. The detection of IgA-s was performed using the ElISA technique followed by the evaluation of the samples using optical spectrophotometry. Those samples with an optical density greater than 0.4 were classified as positive, which means they were able to protect piglets.

It is important to remember that, for the vaccine program to be successful, at least 80% of the sows must be positive, which means they have the capacity to transmit protective immunity to piglets.

3. Results

Results obtained for the quantification of IgA-s in the colostrum on the first day after delivery:

The percentage of positive samples, with an optical density greater than 0.4, was significantly higher in the group treated with immunostimulant pronutrients compared to the control group. In the control group the percentage of positive samples is less than 80% and therefore the effectiveness of the vaccine protocol cannot be ensured. The average value of s-IgA was 1.028 and 0.925 in the control group and in the experimental group respectively.

The group with a third oral vaccination had a positive rate of 100%. The average value was 1.098.

4. Conclusion

Porcine epidemic diarrhea (PED) is a viral disease that causes a high mortality in piglets, especially in those from sows not previously exposed to the virus. Vaccination is the preventive method that allows to prevent the appearance of Porcine epidemic diarrhea (PED), by transmitting s-IgA through the colostrum.

Immunostimulant pronutrients have a significant effect on the concentration of s-IgA and on the percentage of positive sows compared to the control group, vaccinated intramuscularly. In addition, it helps to achieve protection against Porcine epidemic diarrhea (PED), ensuring the effectiveness of the vaccine protocol.

At the same time the effect of immunostimulant pronutrients is like the one obtained with the administration of an additional oral vaccine.

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