Surviving SDCoV with feed additives

31-12-2015 | | |
photo: Ronald Hissink
photo: Ronald Hissink

Using certain kinds of feed additives may reduce Swine Delta Coronavirus (SDCoV) survival in complete feed faster, according to a group of researchers from the University of Minnesota.

SDCoV was first discovered in 2012 in China. Currently, three different types of coronavirus are known to affect pig guts. The most well-known is Porcine Epidemic Diarrhoea virus (PEDv), the other two being Porcine Delta Coronavirus (PDCv) and Transmissible Gastroenteritis virus (TGEv).

The researchers pointed out that feed contaminated with faeces from infected pigs is a potential route of transmission of SDCoV. Organic acids and feed additives are included in diets to improve nutritional value. The objectives of their study were to determine if organic acids or additives at recommended or twice the recommended concentrations are effective in reducing the survival of SDCoV in feed.

In experiment 1, virus was grown and titrated in swine testicular (ST) cells and was added to all vials at 1 mL/vial followed by vortexing and storage of vials at room temperature (25°C) for 5 weeks. In experiment 2, twice the recommended concentration of additives was added to aliquots and experimental conditions were identical to those used in experiment 1 except that virus survival was evaluated on d 0, 1, 3, 7, and 10 of storage. In experiment 1, the researchers observed that it takes 0.86 days to reduce the concentration of virus by 1 log.

None of the additives tested reduced the inactivation kinetics of the virus at recommended doses. However, adding twice the recommended concentration reduced the time for 1 log inactivation in feeds with Acid Booster (0.28 days), Activate DA (0.12 days), and salt (0.09 days).

The researchers point out that ‘further research is needed to determine if there are interactive effects of active ingredients in various feed additives’.

ter Beek
Vincent ter Beek Editor of Pig Progress / Topic: Pigs around the world