Pig farmers, have you ever had this frustrating experience?
You buy vaccines on time and schedule immunizations on time, keep a close eye on the pig farm every day, and spare no expense on labor or vaccines—yet the herd still has problems.
Many people’s first reaction is that the vaccines are poor quality. But based on hands-on experience in the field, most immunization failures are not the vaccines’ fault at all; the problem is that operational details were not handled properly!
Vaccination is not as simple as giving a quick shot. One wrong step, and antibody levels won’t rise, wasting all the effort and money invested beforehand. Today, we’ve put together 7 common pitfalls on pig farms, all drawn from real-world experience. We recommend saving this post.
First, subclinical health in the herd and forced immunization
If pigs have a fever, cough and wheeze, diarrhea, or low spirits, do not rush to vaccinate them.
Blue ear disease, circovirus, and mycotoxins can all cause immunosuppression. The pigs’ immune systems have already been damaged, so vaccination is unlikely to produce effective antibodies and may also easily cause stress-related illness or death.
Correct approach: Isolate and care for sick and weak pigs, and wait until the herd is stable before catching up on immunizations.
Essential pairing: Mycotoxins and subclinical health problems are widespread in pig farms and are the biggest obstacles to immunity. As part of routine care, use a mycotoxin binder periodically to help improve the condition of subclinically affected pigs and restore them to health. This helps eliminate immunosuppression at its source, allowing high-titer antibodies to develop after vaccination and preventing wasted vaccinations and money.
II. Arbitrarily increasing or decreasing vaccine doses
Don’t try to save money by dividing one dose of vaccine among several pigs. There won’t be enough antigen, and antibody levels may not reach the protective threshold;
And don’t assume that using more will produce better results. Blindly increasing the amount can cause immune paralysis and make the vaccination just as ineffective.
Correct approach: strictly follow the instructions for the initial dose; do not arbitrarily increase or decrease the dosage.
Three, choosing the wrong time to vaccinate, resulting in neutralization by maternal antibodies
If piglets are vaccinated while their maternal antibody levels are still high, the antigens are directly neutralized, making the vaccination effectively a wasted shot.
Routine first vaccination against classical swine fever can be given after 25 days of age. If possible, collecting blood samples to test maternal antibodies before deciding the timing is a more reliable approach.
Inactivated vaccines must be followed by a second booster dose. If administered only once, antibody levels do not last long, and protection is insufficient.
IV. Incorrect needle specifications and arbitrary injection sites
If the needle is too short, the vaccine is injected into the fatty tissue, resulting in poor absorption and abscesses, and greatly reducing the effectiveness of immunization.
Match the needle to the pig’s weight; vaccines for diarrhea should be injected at the Houhai acupoint, not uniformly into the neck muscle.
Correct practice: Use one needle per pig to prevent cross-infection.
Essential pairing: Many small-scale pig farms reuse needles, use mismatched sizes, and fail to disinfect them properly, which can easily lead to cross-infection and injection-site inflammation. It is recommended that pig farms keep dedicated disposable injection needles and a needle disinfection box on hand, with sizes suitable for pigs of different weights. This helps ensure accurate intramuscular injections, reduce abscesses, strictly use one needle per pig, prevent latent infections, and safeguard immunization effectiveness.
V. Improper vaccine storage and use
Freeze-dried live attenuated vaccines: store frozen below -15°C; oil-based inactivated vaccines: refrigerate at 2–8°C.
Discard vaccines that have been repeatedly frozen and thawed, exposed to prolonged sunlight, expired, separated, or lost their vacuum. Don’t hesitate.
Allow the oil-based vaccine to warm to room temperature before injection; injecting a cold vaccine directly causes severe stress. Use diluted live vaccine as soon as possible.
A must-have: A one-degree difference in vaccine storage temperature could make the vaccine ineffective. Small and medium-sized pig farms are advised to equip themselves with a small refrigerator-freezer dedicated to vaccines, store freeze-dried and oil-based vaccines in separate compartments, and maintain a constant temperature to avoid repeated freeze-thaw cycles. This helps preserve vaccine potency at low cost and prevent expensive vaccines from going to waste.
Six. Improper medication use before and after immunization.
Avoid immunosuppressive drugs such as dexamethasone, sulfonamides, and florfenicol before and after immunization;
For bacterial live vaccines and live mycoplasma vaccines, try to avoid anti-mycoplasma and other sensitive antibiotics for 7 days before and after immunization, as they directly kill the live vaccine bacteria. Viral live vaccines are not affected by ordinary antibiotics, but immunosuppressive drugs should still be avoided. In addition, some deworming drugs and antipyretic analgesics also carry a risk of immunosuppression, so avoid using them during immunization unless necessary.
Correct approach: Space immunization and medication apart, with an interval of at least 5 days.
Essential pairing: Pig herds are prone to stress and declining resistance before and after vaccination, so medication cannot be used casually. A multivitamin anti-stress product can be used throughout; administer it in feed or drinking water for 3 days before and after vaccination to relieve injection stress and improve herd immunity. It does not interfere with vaccine efficacy and can also help antibodies develop quickly, making it an essential aid during the vaccination period on pig farms.
Seven. Multiple vaccines are drawn into the same syringe and injected.
Never draw multiple vaccines into one syringe and mix them for injection!
Both vaccines need to be administered. Preferably, inject them separately on the left and right sides of the neck. For two live viral vaccines, it is recommended to administer them separately at an interval of 5–7 days for more stable antibody levels.
In closing
Vaccines have never been life-saving miracle cures.
Even if all procedures are followed, disease can still occur despite acceptable antibody levels if the strain does not match or the pig farm’s biosecurity measures are inadequate.
Immunization is all about attention to detail. Many losses at pig farms could have been completely avoided.
If you find this content thoughtful and practical, feel free to save it and refer to it when getting vaccinated. Share it with fellow pig farmers around you to avoid unnecessary detours.