How to prevent and control porcine circovirus type 2 infection

To date, there are still no effective measures to control and eliminate other diseases caused by porcine circovirus type 2 infection, nor are there any truly effective commercial vaccines or drugs available to protect against porcine circovirus type 2 infection. Moreover, porcine circovirus type 2 is highly resistant to conventional disinfectants, which creates difficulties for purification work on pig farms. At present, comprehensive control measures should be adopted.

1. Change and improve raising methods, achieve all-in/all-out production at each stage of @#@227@#@, and avoid mixing pigs of different ages in the same group, thereby reducing and lowering the chances of contact transmission of porcine circovirus type 2 infection between pig herds.

2. Establish a complete biosecurity system on the pig farm, and integrate disinfection and hygiene work into every link of pig production. Minimize pathogenic microorganisms contaminating the pig farm and reduce or eliminate the probability of secondary infections in the pig herd. Because porcine circovirus type 2 is highly resistant to ordinary disinfectants, broad-spectrum disinfectants should be considered when choosing disinfectants.

3. Strengthen the feeding and management of the pig herd and reduce stress factors affecting the herd. Many stress factors can trigger and promote the occurrence of porcine circovirus type 2 infection and worsen the condition of affected pig herds, leading to an increase in mortality. Therefore, stress factors for the pig herd should be reduced as much as possible, feeding moldy, deteriorated, or mycotoxin-containing feed should be avoided, ventilation in the pig house should be done well, the air quality in the pig house should be improved, and ammonia concentration should be reduced. Keep the pig house dry and reduce the stocking density of the pig herd.

4. Raise the nutritional level of the pig herd. Because porcine circovirus type 2 infection can lead to a decline in the immune function of the pig herd, nutrition is an important factor affecting porcine circovirus type 2 infection. By increasing the levels of protein, amino acids, vitamins, and trace elements in the pig herd, improving feed quality, increasing the feed intake of weaned pigs, feeding piglets wet feed or gruel, and ensuring sufficient drinking water for piglets, the incidence rate of porcine circovirus type 2 infection and the losses it causes can be reduced to a certain extent.

5. Adopt a complete drug prevention plan to control secondary bacterial infections in the pig herd. There are no effective drugs that can be used to treat porcine circovirus type 2 infection, and even for some secondary bacterial diseases, treatment results are poor. Therefore, drug prevention should be adopted in advance to control secondary bacterial infections. In view of the disease characteristics of porcine circovirus type 2 infection in China's pig herds at present and the application results in actual production, the following drugs are recommended for prevention plans.

① Piglet medication: Suckling piglets are injected with long-acting oxytetracycline (200 mg/ml) at 3, 7, and 21 days of age, 0.5 ml each time, or injected with ceftiofur (500 mg/ml) 0.2 ml at 1 and 7 days of age and at weaning; from 1 week before weaning to 1 month after weaning, feed with tiamulin (50 g/ton) + chlortetracycline or oxytetracycline or doxycycline (150 g/ton) + amoxicillin (500 g) mixed into the feed, or add 2% florfenicol (1000-1500 g/ton) + tylosin (200-250 g/ton). On pig farms with severe secondary infections, ceftiofur (500 mg/ml) 0.2 ml can be injected at 28, 35, and 42 days of age.

② Sow medication: For sows, during 1 week before farrowing and 1 week after farrowing, add tiamulin (100 g/ton) + chlortetracycline or oxytetracycline (300 g/ton) to the feed.

6. Do a good job of vaccination against swine fever, pseudorabies, porcine parvovirus infection, and enzootic pneumonia on the pig farm. Large-scale pig farms should advocate the use of inactivated Mycoplasma hyopneumoniae vaccine for immunization, which helps improve the immunity of the respiratory tract and lungs of the pig herd and can reduce secondary infections by respiratory pathogens.