Prevention is always a cost-effective way to prevent epidemics. Disease prevention can be achieved through effective biosecurity measures combined with appropriate immunization. However, epidemics can still override these precautions, and when they do occur, it is important to seek veterinary advice. Breeders and service personnel should be trained to identify problems that may cause disease, including observing flock drinking and feeding patterns, bedding conditions, excessive mortality, and unusual flock activity and behavior. The key is to take prompt action to solve the problem.

The parent breeders can effectively transmit maternal antibodies to the next generation of chicks by vaccinating them with a variety of vaccines. These antibodies can provide partial protection in the early stages of chick growth. However, these antibodies do not provide protection for the entire growth process of broilers. Therefore, vaccination is required in hatcheries or at chicken farms. The timing of vaccination should be determined based on maternal antibody levels, associated diseases, and current issues on the farm.

The success of a broiler vaccination program depends on the correct administration of the vaccine. Specific recommendations for vaccine application should be obtained from vaccine suppliers.

General vaccine handling procedures

• Make sure the vaccine is stored at the temperature recommended by the manufacturer.

• The record records the vaccine product type, serial number and expiration date.

• Prepare the vaccine and stabilizer mixture on a clean surface in a clean container free of chemicals, disinfectants, cleaners, or organic materials. (Use stabilizers only under the guidance of the device and vaccine manufacturer).

• Each vaccine vial is submerged in a stabilizer solution and opened.

• Flush each vaccine vial.

Hatchery Vaccination guidelines

Hatcheries have become a very important part of the health program, as many vaccines are administered either intra-embryo or on the day of hatching. This makes it possible to easily vaccinate large numbers of embryos and chicks against many diseases using a unified and accurate immune system. Hatcheries are places where intradermal vaccination can be administered.

Hatcheries have been using spray immunization, Newcastle disease and coccidiosis for years. Be sure to follow the vaccine manufacturer's recommendations for immune effectiveness, as product and manufacturer recommendations may vary.

Broilers placed on old bedding and/or out late may require Marek vaccination at the hatching stage. This is done by injecting at least 1500PFU of HVT vaccine into the embryo or on the day of emergence.

HVT vector vaccines can also be used in hatcheries to prevent infectious laryngotracheitis, Newcastle disease, infectious bursal disease and avian influenza. It is important to note that the HVT vector vaccine requires a full dose so that the vector virus and the inserted virus can meet the amount of the target immune level.

Guidelines for field vaccination

Drinking water inoculation

• The amount of vaccination water should be calculated based on the duration of vaccination of 90 to 120 minutes.

• Get vaccinated early in the morning to reduce stress, especially in warm weather.

• Do not use water rich in metal ions (such as iron and copper).

• The pH of the water should be 5.5 to 6.5. High pH water tastes bitter to chickens, which may reduce water and vaccine intake.

• Stop water 1 hour before vaccination starts to ensure rapid vaccination.

• Using a dye or color stabilizer approved by the vaccine manufacturer may help determine when to start the water hose and how many birds consumed the vaccine.

• Turn off the chlorinator 48 hours before vaccination.

• Clean the water filter 48 hours before vaccination to remove chlorine residue. Use non-chlorinated water to clean the filter.

• If using UV light, turn off the UV light, as this may inactivate the vaccine.

  • If drugs are used, not all birds can be vaccinated.

Vaccine preparation

1. Always follow the manufacturer's instructions. Use 30% of the previous day's total water consumption to calculate the amount of water needed. If no water meter is available, use the following calculation: The number of chickens in thousands multiplied by their age in days multiplied by 2. This is equal to the amount of water (in liters) needed to administer the vaccine in 2 hours.

2. Prepare commercial stabilizers according to manufacturer's recommendations to neutralize chlorine in drinker lines. Or, mix 2.5 grams of skim milk powder per liter of water. Prepare the skim milk solution 20 minutes before vaccination to ensure that the skim milk powder neutralizes the chlorine present in the water.

3. Prepare the dye solution. The dye will be used to visually confirm the presence of the vaccine in the water.

waterline

1. Raise the water line.
2. Pour the prepared vaccine, stabilizer and color solution into the header tank or water storage tank.
3. Fill the waterline until the stabilizer or stain reaches the far end of the waterline.
4. Reduce the drinking line and allow the chickens to drink the vaccine, ensuring that the water is used up before the tank is emptied.
5, walk slowly in the flock to stimulate drinking water and improve the uniformity of drinking water.
6, record the vaccine consumption time, and adjust the equipment to control the time, so that the next application is convenient for chickens of similar age, to achieve a time of 90 to 120 minutes.

Bell water fountain

1. Open the bell drinking system.
2. The vaccination program requires two people. One person mixes the vaccine solution and the other person adds the mixture to the water fountain.
3, clean each water fountain, empty the water and bedding. Do not use disinfectant to clean drinking water containers.
4. Carefully fill each water fountain. Do not overfill or spill the vaccine solution.
5. During vaccination, walk around the coop and drive chickens near the wall to the water fountain.

Monitoring drinking water vaccine intake

1. Start monitoring chickens after vaccination.
2. Select 100 chickens per coop and check how many have dyed tongues, beaks or crops.
3, divide the coop into four parts, and check the dyeing of 25 chickens in each zone.
4. Calculate the percentage of dyed chickens.
5. Vaccination is considered successful when 95% of chickens show staining after only 2 hours.

Aerosol/spray vaccination

The spray vaccination needs to be carefully managed. The spray vaccine solution can be lost through evaporation, sedimentation and drift before it reaches the birds.

Vaccination equipment should be repaired in accordance with the manufacturer's instructions to ensure correct function and correct particle size step.

One-day farm spraying requires a specific type of sprayer. (Please check with the vaccine manufacturer.)

Check that vaccination equipment is working at least 1 week before vaccination to allow time for repairs if needed.

Operators who are inexperienced with specific house conditions and equipment should practice using plain water to verify walking speed.

Only the nebulizer is used for vaccination. Never put disinfectants or chemicals (including insecticides) in the sprayer.

Use fresh, cool, distilled water. Ions or chlorine in tap water can inactivate some vaccines.

Rinse the nebulizer with distilled water and retain a small amount of liquid before adding the diluted vaccine.

The average spray rate is 15 to 30 liters per 30,000 chickens. (Please check with vaccine and device manufacturers for specific quantities.)

If a fine drop spray is used, the amount of water is 1 litre per 30,000 chickens.

Getting vaccinated early in the morning can reduce stress, especially in warm weather.

Aerosol/spray vaccination program       

Turn off the fan before spraying begins. Dim the lights to reduce the stress of the chickens and allow the vaccinator to move easily within the coop.

Spray coarse drops along the length of the coop. The distance between the vaccinator and the side wall must not exceed 4 meters.

The spray height should be about 1 meter higher than the chicken.

Tilt the sprayer nozzle down

Move slowly through the flock.

After spraying, keep the fan off for 20 minutes, provided the chickens are not heat stressed or supervised.

After vaccination, the nebulizer is flushed with distilled water, and the remaining vaccine is then flushed by dispensing water. Allow vaccination equipment to air dry in a clean, dust-free environment. Proper maintenance of this valuable equipment is important to ensure a continuous supply of vaccines for future flocks.