The immunological importance of swine fever before sucking does not suck colostrum
Pre-immune immunization, also known as zero-time immunization or pre-immunization, is the depriving of suckling colostrum after the birth of the piglet, and then sucking in colostrum after a certain period of time after the vaccine is injected. For a long time, our country has used swine fever vaccine as an important means to control swine fever. In particular, those sows whose long-term high-dose, high-frequency vaccines are injected are basically in a high-exempt state. They also have high levels of antibodies secreted by colostrum, and pass the antibodies through the colostrum to the piglets. These antibodies are also found in piglets. Physical memory stays longer. Since the swine fever vaccines currently used are basically all attenuated swine fever vaccines, the parental antibody will have an inhibitory effect on the active immune response when the newborn piglet receiving maternal antibody is vaccinated again. In order to avoid the interference of maternal antibodies against active immunity, pre-vacuum immunization was performed and proved effective through research experiments. We had previously conducted a comparison of a previous immunization with a Beijing veterinary workstation and 20-day-old and 60-day-old immunizations. After 4 weeks, both groups of animals reached a positive standard for immunizing antibodies at 9 months and 12 months. In the challenge experiment, all groups of immunized animals were protected and all control animals died. The two immunization programs proved to be fully effective and did not show significant differences. We have also conducted three different immunization programs with 0-35-70-day-old immunization, 0-70-day-old 2 epidemic, and 0-day-old immunization in cooperation with a pig farm in Guangdong Province. The anti-enzyme method followed the immunizing antibody to 180 days of age. The results showed that the immunization procedure of O ~ 35 ~ 70Fj was slightly better than that of 0. 70 days and 0 days of immunization. We have also compared the effects of 3 different immunizations with 20-60-day-old immunization, 35-day-old immunization, and 0-day-old immunization with the relevant units in Hebei Province. Track immune antibodies to 90 days of age. The results showed no significant differences in the immune effects of the three immunization programs. The above-mentioned zero-day-age refers to pre-emulsion (pre-immune). From the above experiments, pre-milk immunization is effective and practical. Pre-vaccinal immunization has also been used extensively in the field, especially in large and medium-sized pig farms. However, in practice, it is difficult to completely achieve that all piglets do not suck colostrum after birth. Especially those large-scale mechanized pig farms often have multiple sows that are at the same time farrowing, and a few birth attendants are more difficult to care for. In order to clarify the effect of first injection of colostrum and first injection of colostrum seedlings on the immune effect, it is possible to solve the problem that even a small number of newborn pigs suck colostrum and receive the vaccine injection. Field, Guangdong Veterinary Institute and Guangdong Biopharmaceutical Company conducted comparative trials. The piglets born on the same day were equally divided into 3 groups of 13 to 15 heads. The first group did not receive colostrum, and then sucked colostrum 1 hour after the injection; the second group first sucked the colostrum, and then injected the vaccine 1 hour later; the third group first sucked the colostrum and injected the vaccine half an hour later. At the age of 80 days, 4 pigs were randomly taken from each immunization group and challenged with 6 non-immune pigs. The challenge results were: control group 6/6 (100%) death; group 1/4f 100%) protection; group 2 3/4 (75%) protection; group 3 2/4 (50%) protection. All of the experimental organs were examined using the swine fever immunoassay antibody (fHCFA): All control pigs and immunized pigs were negative before the challenge; 12 to 14 days after the challenge, all non-immune control pigs and dead immunized pigs were Particularly strong swine fever antibody was positive, and all immune challenged swine were negative. It can be seen that the immune effect of reinjecting the vaccine 1 hour or half an hour after sucking colostrum is not as good as the immunization effect without first sucking the colostrum. Therefore, in the practice of pig production, it is difficult to do 100% of piglets without first immunizing with colostrum during pre-vaccination immunization. However, in order to obtain a good immunization effect, it should be adhered to and strongly advocated not to attract early. Milk injection is appropriate first. Here are some personal opinions on the problem of pre-milk immunization of swine fever: 1. The extensive use of the test and Tian-Qian proves that pre-mammal immunization of swine fever is effective and can avoid the interference of maternal antibodies on active immunity. It is recommended that the conditional pig farms be used as far as possible to effectively protect piglets against infections of piglets during the lactation and nursery stages. 2. Since the maternal antibody significantly interferes with active immunity, the immune effect is greatly affected. Therefore, the pre-milk immunization must be done so that the piglet does not suck the colostrum and achieve complete “milk pre-immunization†immunity. The specific approach is to isolate the piglets after they are born, and to inject the swine fever vaccine. After a certain time interval, the breast milk will be sucked again. How long does it take to suck breastmilk again? It is advisable to take l hour. It is not necessary for 2 hours or 3 hours. Too long time may have an adverse effect on the growth and development of piglets. As mentioned earlier, our experiments have demonstrated that colostrum can be aspirated at 1 hour after the vaccine is injected, and its protective power can reach 100%. At present, most pig farms use a 1-hour time interval. 3. Under laboratory conditions, only one pre-vaccination immunization will ensure a minimum of one year's protection from swine fever. However, in the more complex conditions in the field, one must not rely on a pre-vaccination immunization. At present, some pig farms are affected by swine fever at different levels. Consolidating and improving the pig's immunity to swine fever is still an important task for pig farmers. According to my practice and experience of Tian Wen over the years, I believe that pigs only have one immunization and their antibodies can only last for about 70 days. If you do not do booster immunity around the age of 70 days, it is easy to have swine fever. This has happened in some farms, causing some loss. Therefore, it is recommended that in non-pig feedstuffs pigs, pre-embryo immunizations of 1 to 2 piglets, attenuated vaccines (cell seedlings), and injections of similar vaccines at the age of 70 days of 2 to 4 doses, should be unnecessary. Re-immunize until slaughtered. If reserved for reserve breeding pigs, an immunization is carried out before the breeding and the breeding program is followed by a breeding program. If pigs are contaminated by pig farms, they should be immunized with 0 to 35-70 days old immunization procedures. After taking pre-embryonic immunizations with 1-2 rabbits for attenuated vaccine (cell seedlings), four vaccines of the same kind were administered at 35 and 70 days of age, respectively, until slaughter. If reserved as a back-breeding pig, it will be immunized once before the breeding and later according to the breeding program of the breeding pig. 4. When pre-vaccination immunization, each litter of piglets can share a single syringe, but it is not possible to share a single needle. This is because if the sow is infected with swine fever, the swine fever virus can be transmitted to the fetus through the placental barrier and the infected swine The litter of the same litter was not congenitally infected at every head, and the proportion of piglets infected was related to the degree of sow infection. As a result, sharing a needle is likely to cause artificial cross-infection among piglets, which must be avoided. In the specific operation, it is recommended to use a 5 ml disposable plastic syringe to achieve the precise purpose, and the needle is to be recycled using stainless steel needles. In short, the pre-milk immune effects of swine fever are obvious and the operation is not difficult. If it can be done without first sucking colostrum and avoiding interference from maternal antibodies, this measure is very beneficial to the prevention of swine fever.