Abstract:

In order to formulate scientifically immunization programs to control PRRS basically, the maternal antibodies and immune antibodies of sows, sucking pigs and piglets were detected respectively by ELISA diagnostic kits. Trials have proved that the first immunization of the breeding sows was 15 days before hybridization, and the second immunization of pregnant sows was 2 months before pregnancy, the third immunization of the breeding sows was 15 days before the second hybridization, this production cycle of immunization can control PRRS infection. Because after the parturient sow 1 month immunized PRRS inactivated vaccine, the maternal antibody of piglets decreased gradually and was negative at 60 days, the first immuniza-tion of piglets was approximately 45-day-old, besides. When 40-day-old piglets PRRS were immunized inactivates vaccine, the antibody S/P average of 58-day-old was the highest, and the 160-day-old was negative which could not resist the infection of PRRSV. Injecting the 40-day-old piglets were immunized 2 mL PRRS inactivated vaccine by intramuscular, the second immunization was 70-day-old, then the antibody S/P value was the average maximum at 85-day-old, the 180-day-old finishing pigs was still positive. Therefore, the pigs were safe as the stock exchange, or immunized before hybridization as a back-up sows in breeding. The antibodies of non-immune sows and piglets were negative in control group. The fluctuation law of PRRSV maternal antibodies and immune antibodies by the experiment affords a theoretical basis for the development of immunization programs in the future.

Key words: ELLSA detection; PRRS; maternal antibody; immune antibody