Resorption of antibodies after oral application of spray-dried porcine blood plasma to new-born piglets

Introduction Infectious diseases in the suckling period of pigs are common and cause financial losses. To improve the health of the piglets and decrease the use of antibiotic drugs, sufficient immunological protection is necessary. In suckling piglets, the oral intake of antibodies is a highly effective measure for protection. We tested whether antibodies in spray-dried blood plasma of pigs can be absorbed by newborn piglets after oral application. Materials and Methods The spray-dried plasma was positive for antibodies against the porcine reproductive and respiratory syndrome virus (PRRSV), the porcine circovirus 2 (PCV-2), the porcine epidemic diarrhoea virus, the porcine parvovirus and others. The study was conducted on 210 suckling piglets in a pig breeding farm in Austria. The newborn piglets were randomly divided into four groups: K, P, P+bov and P24. Group K received no treatment; group P received spray-dried plasma orally before the first intake of colostrum; group P+bov received spray-dried plasma dissolved in bovine colostrum; and group P24 received spray-dried plasma 24 hours after birth. In addition to blood samples of the mother sows, blood samples were taken from the piglets on days zero, one, seven, ten and 14 after application of the spray-dried plasma. The serum was tested by ELISA for the antibodies in the spray-dried plasma. The antibody resorption and clinical outcome were compared between the groups. Results All sows were PRRSV antibody-negative. 24 hours after application of the spray-dried plasma, seven piglets in group P and six piglets in group P+bov were PRRSV antibody-positive. The PRRS-specific antibody levels in these two groups were significantly higher than those in groups K and P24. All piglets from PCV-2 antibody-positive sows were positive after 24 hours. However, eight of the 24 piglets from PCV-2 antibody-negative sows from group P, ten (of 24) from group P+bov and seven (of 24) from group P24 PCV-2 were antibody-positive 24 hours after the application of spray-dried plasma. All piglets in group K stayed PCV-2 antibody-negative. No effect on the piglets' clinical performance was found. Conclusion The study proves that antibodies from spray-dried plasma applied within 24 hours after birth can be absorbed by newborn piglets. However, the resulting antibody levels were too low to give more antibody-positive results by ELISA.