Improving your PRRSv prognosis
Porcine Reproductive and Respiratory Syndrome Virus (PRRSv) continues to be a primary challenge for pig producers, with reproductive failure and respiratory illness leading to dramatically reduced animal performance and increased morbidity and mortality. As we head into winter, we typically see a spike in PRRS cases due to the virus’s preference for cool, moist environments. It is estimated that the global cost of PRRSv exceeds US$7 billion every year, making it one of the most economically destructive animal diseases.
It has now been conclusively proven that feed can be a source of PRRSv. The diverse range of raw materials and the variety of regions where they are grown and processed can be problematic. One of the most challenging features of PRRSv is its long-term impact. Once a pig catches it, the virus can continue to spread for very long periods of time, dramatically impacting long-term herd performance. With no cure currently available, we need strategies to improve prognosis and get performance back on track when an outbreak does occur.
Recent scientific research indicates promising ways to mitigate in-feed pathogens. VevoWin is a solution based on pure benzoic acid coupled with the natural power of essential oils that has been tested for its ability to mitigate viral transmission in feed for numerous pathogens, including PRRSv, PEDv and African Swine Fever. The solution balances the acid-binding capacity of the feed, easing acidification for a healthier microbiome, which in turn reduces the incidence of diarrhoea while also improving performance parameters. Unlike many feed mitigant solutions, this solution is provided as a high-quality, free-flowing powder.
Research in 2020 examined the efficacy of the acidifier and essential oil solution in preventing the transmission of PRRSv. In this study, ice blocks were inoculated with various viruses, including PRRSv. The ice blocks were subsequently dropped into the tops of three feed silos. Two silos were treated with either 3kg/t or 5kg/t of VevoWin.
The feed was then fed to 4 sheds of nursery pigs for 15 days. On days 0, 6 and 15, oral fluids were collected from pigs, and feeder samples were taken. On day 15, serum was tested for PRRS. Performance was measured throughout.
The study found that 100% of the pigs in the positive control group tested positive for PRRSv on day 15; however, none of the pigs on either treatment tested positive for PRRS. Likewise, while 100% of the control pigs showed clinical signs of disease, none of the pigs receiving the additive showed any clinical signs of disease.
When the performance results were compared, these reflected the disease status, with the control groups having significantly the lowest average daily gain (ADG) of 140g/ day compared to both treatments that achieved ADG of 499 and 540g/day, respectively.
When feeders were tested on day 15, the acidifier and essential oil solution reduced positive samples by 66.7% and 83.4%, respectively. This demonstrated that not only was the rate of positive samples significantly reduced, but even when infection was present in the feeders, no clinical signs of disease were seen in the pigs.
Interestingly, a recent study has also shown that the acidifier and essential oil solution can improve health and performance following a PRRSv break.
Figure 1 – Comparative farrowing rate before and after VevoWin implementation during a PRRSv outbreak.
Dr Satoshi Otake looked at the effect of VevoWin on productivity recovery following a clinical break of PRRSv. The study demonstrates the impact of the additive in a farrow-to-finish unit in Japan that experienced a significant PRRSv break in February 2023. By April 2023, the farrowing rate was reduced by 50% and pre-weaning mortality was at 80%.Throughout 2023, serum PRC from sows was constantly positive, indicating that sows were viraemic and shedding the virus in breeding/gestation. Supplementation was implemented in December 2023 and has continued to date. By July 2024, the farrowing rate had improved to 90% of the breed standard (Figure 1), and pre-weaning mortality had reduced to just 10% (Figure 2).
Figure 2 – Comparative pre-weaning mortality before and after the acidifier and essential oil solution supplementation.
These results suggest that VevoWin can be an essential tool for preventing in-feed transmission of PRRSv and supporting the devastating performance effects of the virus when an outbreak does occur.
References available upon request
