IAV-S and the impact on growing pigs
Growing pigs in the U.S. face the threat of numerous respiratory pathogens throughout their growing period, creating a significant impact on productivity and profitability.1
It has been shown that when uncomplicated, influenza A virus in swine (IAV-S) can lead to an estimated loss of more than $3 per pig.1 When present with concurrent infections, such as porcine reproductive and respiratory syndrome virus (PRRSV), the loss can be greater than $10 per pig.1
Until now, phase-specific respiratory pathogen burden, from the time of weaning to marketing, has not been well characterized. This poses a considerable challenge to producers to effectively evaluate the association between the timing, duration, and concurrent infection of key respiratory disease agents and performance outcomes.
A recent study reported by Iowa State University analyzed the burden of respiratory disease during the growing period as it relates to multiple pathogens, IAV-S as well as PRRSV.2
Studying pathogen burdens through production
The study described by Iowa State University measured pathogen burden from oral fluid sampling. Forty-five flows (independent groups of pigs) were sampled every 2 weeks from nursery placement through closeout. The results of these diagnostics determined three main "patterns" of burden for each pathogen. The study then coupled the diagnostic data with the total mortality data reported for each enrolled group.
Flows that were seen to have growing nursery pathogen burdens (pattern 2, moving from low to moderate-high pathogen burden in the nursery) had the highest average mortality rates; over 40% greater than any other pattern for IAV-S, and 80% greater than any other pattern for PRRSV. Based on these mortality rates, average daily gain (ADG) for the affected flows would be expected to be significantly lower.
In flows that fit both IAV-S pattern 2 and PRRSV pattern 2, this compounded late nursery pathogen burden affected overall mortality rates even more, climbing from 10.4% and 10.1%, respectively, for the individual pathogens to a combined 13.7%.
Controlling IAV-S leads to better health outcomes1
The presence of an increased burden of respiratory pathogens inevitably leads to increased numbers of diseased pigs. When pigs are affected by respiratory disease, lost productivity has been shown to impact the ability of pigs to reach their full potential.1
Ensuring that young pigs are protected against IAV-S through all production phases is crucial for maintaining optimal productivity. For more information on vaccination control strategies, visit www.aboutswineinfluenza.com.