- 4 minutes, 9 seconds
- Expertise article
- S.-H. Moon*, Y.-S. Lyoo, S.-H. Noh, M.-H. Kim et. al.
PO-PW1-145
Field experiences with concurrent vaccination strategy aiming to control breeding performance in PRRS in large pig farms
Introduction: PRRS virus was identified in 1990' earlier and classified two group in type 1 and type 2 genetically. PRRS virus has been discovered all over the world. PRRS modified live virus vaccines are introduced in many country to control PRRS. But these PRRS live virus vaccines didn't defend against heterologous PRRS virus perfectly. This field case shows reproductive performance after type1 modified live virus vaccination when it is infected with type 1 wild PRRS virus and its symptoms are severe ehile using type 2 modified live virus vaccine in a large farm.
Materials and Methods: this farms are separated in five reproductive farm independently (530, 980, 930, 930, 940 sows) in identical area. Each farm was already identified type 2 PRRS virus about 18% different from VR-2332 ORF5 sequence and have type 2 modified live vaccination to sows quartely to control PRRS strategically (MLV, 2.0ml). Tpe 1 wild PRRS virus was identified in Dec 2013. And in Jan 2014 type 1 modified live virus vaccine (Amervac, 2.0ml) was introduced. In 2014 type 1 and type 2 modified live virus vaccines (each vaccination 2.0ml) are currently used quarterly (in 2014 total PRRS modified live vaccination 10 times) and type 2 modified live vaccine were introduced in 3 weeks weaning piglets contonuosly. Serum samples were tested using PRRSV ELISA and RT-PCR was performed from blood samples befores quartely PRRS modified live virus vaccination. Blood samples in sows 10, nursery piglets, 10 40dys piglets 10, 70dys piglets 10 and replacemnet gilts 10 are collected from each five farm.
Results: a year later after concurrent vaccination with MLV (2.0ml) and AMERVA (2.0ml) no wild type PRRS virus was detected in the sera of the sows and replacement gilts but type 1 PRRSV or type 2 PRRSV are still detected in the sera of the nursery piglets, 40dys pigs, 70 days pigs. But the performance of reproduction are significantly improved in 2014 compared with 2013. IN 2013 total 616 sows in all five pig farm are aborted with infection of PRRSV. In 2014 total sows are aborted. And total mortality rate has reached 11.7% in 2013, but total mortality rate have decreased by 0.7% in 2014.
Conclusion: large-scale five farms are concentrated in identical areas and it is difficult to maintain biosecurity of these farms and prevent PRRS infection outside. Despite of detecting PRRSV in piglets, 40 days and 70 days concurrent type 1 and type 2 PRRSV vaccination has enhanced breeding performance especially about 400 sows without abortion have contributed to increae production volume in farms.
Disclosure of interest: none declared
Keywords: none
Viral and Viral Diseases
PRRS
PO-PW1-109
Evaluation of the impact of PRRSv infection on growth performances of growing pigs in a panel of French herds
M. GOSSELIN1*, N. DEVILLE2, P. GAMBADE1, S. LOPEZ1, N.ROBERT3, E. LEWANDOWSKI2
1UNIVET Santé Elevage, LOUDEAC, 2 CYBELVET, ESTRELLES, 3BOEHRINGER INGELHEIM FRANCE, PACE, France
Introduction: Holdtkamp (2013) estimated the cost of Type II PRSv infection fot the pigs industry in the Unite States (US) to be 2,24€/marketed pig (based on 77% seroprevalence in US - ie = 2,90€/marketed pig in positive herds, economic impact on sows excluded). In Europe, PRRSv type I is the most frequent and is generally considered as less virulent as type II. Few data exists on PRRSv type I economic impact. The objective of this study is to evaluate in a panel of French herds without specific clinical signs, the prevalence of PRRS infection and its potentional economic impact on growing pigs.
Material and Methods: this study was performed between September 2014 and June 2015 in Brittany (France). To be included in the study every farm has to have lonitudinal registered data (wean-to-finish Average Daily Gain - ADG, Feed Conversion Ratio - FCR and Mortality).
In each herd, 10 pigs were blood sampled at the end of the fattening period (21 to 28 weeks of age) in order to establish PRRS status. Sera were pooled by 5 and assayed for PRRSv antibodies by Elisa (PRRS X3, Idexx). Given a prevalence of 30% of seropositive pigs in a population, a sample size of 10 pigs allows to detect the infection with a confidence level of 95%. A herd was defined 'positive' if at least one pool was positive and 'negative' if the two pools were negative.
results: a total of 41 herds were included in the panel. Twenty two farms were classified as 'negative' and 19 were classified as 'positive'. At the herd level PRRS prevalence is 46%. ADG was significantly higher in 'negative' herds compared to 'positive' herds (775 g/d versus 737 g/d, p >0,01), whereas differences in FCR and mortality were not statistically significant (2,48 versus 2,52 and 4,6% versus 4,9% respectively).
Conclusion: this study demostrates the impact of PRRSv type I infection in growing pigs in France, with +38 g/d of ADG between 'negative' and 'positive' herds. Compared to Holdtkamp (2013) we show more impact on growth and less on mortality. Economically, with 2015 figures, differences in performances between 'negative' and 'positive' herds represent in this study +3,15€/pigs.
Disclosure of interest: none declared.
Keywords: Average Daily Gain, PRRSV