Lack of Evidence for African Swine Fever Infection or Transmissibility in Experimentally Infected Rats

Date Received: Jun 05, 2025

Date Accepted: Sep 08, 2025

Date Published: Sep 30, 2025

DOI: https://doi.org/10.31817/vjas.2025.8.3.

Views

8

Download

1

Issue: Vol. 8 No. 3 (2025): Vietnam Journal of Agricultural Sciences

Section:

ANIMAL SCIENCE – VETERINARY MEDICINE – AQUACULTURE

How to Cite:

Dinh, T., Russ, D., Robert, T., & Nga, N. (2025). Lack of Evidence for African Swine Fever Infection or Transmissibility in Experimentally Infected Rats. Vietnam Journal of Agricultural Sciences, 8(3), 2634–2641. https://doi.org/10.31817/vjas.2025.8.3.

Lack of Evidence for African Swine Fever Infection or Transmissibility in Experimentally Infected Rats

Ton Vu Dinh 1 , Russ Daly (*) 2 , Robert Thaler 3   , Nguyen Thi Nga 1

  • Corresponding author: [email protected]
  • 1 Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi 12400, Vietnam
  • 2 Veterinary and Biomedical Sciences Department, South Dakota State University, Brookings, SD 57007, USA
  • 3 Animal Science Department, South Dakota State University, Brookings, SD 57007, USA

    • Keywords

    African Swine Fever, biosecurity, disease transmission, rodents, vectors

    Abstract


    African Swine Fever Virus infections have significantly impacted swine production in many parts of the world. Rodents are considered vectors of several swine disease agents but their role in ASFV transmission has not been determined. This work sought to determine whether rats could be experimentally infected with ASFV. In a pilot project prior to the experimental trial, 27 rats, mice, and shrews were trapped from 3 farms (range 7-10 per farm) with current ASFV outbreaks. These animals were euthanized, sampled, and tested for ASFV with polymerase chain reaction (PCR). None of the samples (n = 81) were PCR-positive for ASFV. The experimental trial utilized 45 commercially obtained rats (Rattus norvegicus domestica): 9 were orally inoculated with ASFV, 9 were intraperitoneally inoculated with ASFV, 18 were non-inoculated contacts, and 9 were negative controls. On each of days 7, 14, and 21 post-inoculation, 3 orally inoculated, 3 intraperitoneally inoculated, 6 non-inoculated contacts, and 3 negative control rats were euthanized, sampled, and tested for ASFV with PCR. Clinical signs did not develop in any of the rats. Body temperatures increased during week 2, but there was no difference between the inoculated and non-inoculated groups. None of the samples (blood, spleen, liver, lung, ileum) were PCR positive for ASFV. Serum tested with ELISA for ASFV antibodies was negative. Despite direct ASFV challenge, inoculated rats did not develop clinical disease symptoms or transmit ASFV to contacts. Further work is necessary to demonstrate the competence of rodents as biological vectors for ASFV transmission in swine herds.

    References

    Abraham A., Nalle R. M., Hampson D. J., Mullan B. P., Pluske J. R. & Wilkinson S. G. (2019). Variability in the nutritional composition and anti-nutritional factors of Australian sweet lupin (Lupinus angustifolius) cultivars. Animal Feed Science and Technology. 247: 153-162.

    Antongiovanni M., Sirtori N., Antongiovanni E. & Sirtori C. (2016). Effects of dietary tannin extract on feed intake and performance of growing pigs. Italian Journal of Animal Science. 15(1): 111-116.

    Bohumila S., Vyskocilova M. & Trncova T. (2009). Digestibility of nutrients and energy in lupin seeds for growing pigs. Veterinarni Medicina. 54(5): 212-218.

    Choct M. (2015). Feed non-starch polysaccharides for monogastric animals: classification and function J Animal Production Science. 55(12): 1360-1366.

    Ciurescu G., Dumitru M., Lefter N. A. & Râmbu D.-T. (2025). Effects of Increasing Dietary Inclusion of White Lupin on Growth Performance, Meat Quality, and Fatty Acid Profile on Growing-Fattening Pigs. 15(15): 1709.

    Department of Livestock Production (2019). Report on the situation of pig husbandry and development orientation (in Vietnamese).

    Department of Livestock Production (2025). Report on pig husbandry in Q4 2024 (in Vietnamese).

    Donovan D., Barneveld R. J. & Pluske J. R. (1993). The feeding value of Australian sweet lupins (Lupinus angustifolius) for pigs. Recent Advances in Animal Nutrition in Australia. 4: 153-162.

    FAO (2023). The future of food and agriculture – Drivers and triggers for transformation. Food and Agriculture Organization of the United Nations, Rome.

    Gdala J., Jansman A. J. M., Buraczewska L., Huisman J. & van Leeuwen P. (1997). The influence of α-galactosidase supplementation on the ileal digestibility of lupin seed carbohydrates and dietary protein in young pigs. Animal Feed Science and Technology. 67(2): 115-125.

    Gidley M. J. & Yakubov G. E. (2019). Functional categorisation of dietary fibre in foods: Beyond ‘soluble’ vs ‘insoluble’. Trends in Food Science & Technology. 86: 563-568.

    Jacyno E., Wieczorek Z. & Swiergiel R. (1992). The effect of lupin seeds in diets on the growth and carcass quality of fattening pigs. Annals of Animal Science. 19(2): 139-147.

    Kemm E. H., Smith R. H. & Siebrits B. D. (1987). The effect of alkaloid levels in lupin seed on feed intake and growth of weanling pigs. South African Journal of Animal Science. 17(3): 109-113.

    Kim J. C., Mullan B. P., Barneveld R. J. & Pluske J. R. (2006). The use of Australian sweet lupins in pig diets. Recent Advances in Animal Nutrition in Australia. 15: 121-132.

    Konizecka H., Smulikowska A. & Jankowski J. (2017). Chemical composition and nutritional value of white lupin seeds for pigs. Journal of Animal and Feed Sciences. 26(1): 34-40.

    Lucas M. M., Stoddard F. L., Annicchiarico P., Frías J., Martínez-Villaluenga C., Sussmann D., Duranti M., Seger A., Zander P. M. & Pueyo J. J. (2015) The future of lupin as a protein crop in Europe. Frontiers in Plant Science. 6: 705. DOI: 10.3389/fpls.2015.00705.

    Márcia F. M., Carvalho S. L. & Silva L. M. (2014). Digestibility of lupin (Lupinus albus) protein and energy for pigs. Livestock Science. 160: 154-159.

    Nalle R. M., Kim J. C., Mullan B. P., Pluske J. R. & Wilkinson S. G. (2011). Nutrient composition and anti-nutritional factors in Australian sweet lupin cultivars. Journal of Animal and Feed Sciences. 20(4): 365-375.

    Nalle R. M., Kim J. C., Mullan B. P., Pluske J. R. & Wilkinson S. G. (2012). Characterization of anti-nutritional factors in Australian sweet lupin (Lupinus angustifolius) cultivars. Animal Feed Science and Technology. 171(2-4): 153-160.

    National Research Council (2012). Nutrient requirements of swine (11th rev. ed.). National Academies Press. Washington, DC. DOI: 10.17226/13298.

    Noblet J. & Perez J. M. (1993). Prediction of digestibility of nutrients and energy values of pig diets from chemical analysis. Journal of Animal Science. 71(12): 3389-3398. DOI: 10.2527/1993.71123389x.

    Petterson D. S., Macpherson G. D. & Kelly J. S. (1997). Anti-nutritional factors in lupins. In: Proceedings of the 8th International Lupin Conference. Asilomar, California, USA.

    Petterson D. S., Barneveld R. J. & Pluske J. R. (2000). Lupin seed in pig feeding. Recent Advances in Animal Nutrition in Australia. 11: 133-144.

    Sharifuzzaman M., Mun H.-S., Ampode K. M. B., Lagua E. B., Park H.-R., Kim Y. H. & Yang C.-J. (2024). Smart Pig Farming—A Journey Ahead of Vietnam. Agriculture. 14(4): 555. DOI: 10.3390/agriculture14040555.

    Sonta B., Balint T., Lukac S., Catic A. & Tesanovic D. (2016). Effect of partial replacement of soybean meal by lupin (Lupinus albus) on performance and carcass quality of growing-finishing pigs. Journal of Central European Agriculture. 17(4): 915-927.

    USDA (2024). Oilseeds: World Markets and Trade – April 2024. United States Department of Agriculture, Foreign Agricultural Service.

    van Barneveld R. J. (1999). Understanding the nutritional chemistry of lupin (Lupinus spp.) seed to improve livestock production efficiency. Nutrition Research Review. 12(2): 203-230.

    Wilkinson S. G. (2017). Lupin (Lupinus angustifolius) as a protein source for pigs. Livestock Science. 197: 1-9.

    Zett V., Wunsche W. & Kreienbring K. (1995). The effect of lupin (Lupinus albus) on the performance of fattening pigs. Archiv für Tierernährung. 48(2): 155-164.