Vaccination with Ingelvac PRRS MLV for PRDC control in Korean swine farm

PRDC is regarded as one of the most serious problems in worldwide swine production recently. There are many pathogens involved in PRDC such as PRRSV, PCV2, SIV, MH, HPS, APP, and PM etc. PRRSV among them could cause disease on its own, and cause immunosuppression of infected pigs, resulting in increased susceptibility to secondary bacterial infection. The main purpose of this study was to reduce mortality and to increase performance using Ingelvac PRRS MLV in Korean swine farm that was affected by PRDC.

This field study was conducted in a 250 sow two-site farm located in Korea. In this farm situation, breeders and nursery pigs are on one site and finishers on another site. After weaning, pigs stay in site 1 until 90 days old and transferred to site 2. Transferred pigs are naïve pigs against PRRSV. Even though PRDC occurred in site 2, pigs in site 1 were continuously confirmed as PRRSVnegative.

Affected pigs in site 2 showed diverse clinical signs including lethargy, anorexia, coughing, labored breathing and death. Because their poor growth performance led to overcrowding in the barn, more complex problems occurred. For that reason, antibiotics and feed additives were supplied to site 2, but PRDC was not solved. After traditional treatments with antibiotics and feed additives, mortality rate slightly decreased temporarily. After 5 month Ingelvac PRRS MLV vaccination was initiated. To obtain best performance of vaccine, all nursery pigs in site 1 were vaccinated at 3-4 weeks before moving to site 2. Mortality rate in site 2 was checked monthly.

Before traditional treatments, mortality rate was above 13%. Mortality rate reduced to 5% temporarily after traditional treatments. However, mortality rate increased up to more than 10% after a few months After Ingelvac PRRS MLV vaccination of pigs in site 1, average mortality rate in site 2 went down to 2%. Not only did the clinical signs largely disappear, the pigs in site 2 also showed improved growth performance, which helped to solve an overcrowding problem.

In this case where PRDC was caused by PRRSV as the primary pathogen, controlling of PRRSV infection by implementation of vaccination strategy, was the main solution to improve clinical disease. The vaccination strategy also improved production performance. In general different methods can be applied to control respiratory diseases. PRRS MLV vaccination is an important part of the solution when PRRS is involved in a PRDC problem. A strategy of PRRSV MLV vaccination at 3-4 weeks before PRRSV infection is a promising method for providing sufficient immunity to pigs against PRRSV.

Disclosure of Interest: None Declared.