Vaccinations can prevent and stop the outbreak of dangerous diseases in young and laying hens as early as the rearing phase. What types of vaccine are available? What are common sources of error when vaccinating, and which vaccination techniques are used? Dr Kristian Düngelhoef, a specialist in poultry medicine, addressed these questions during an online event organised by the North Rhine-Westphalia Chamber of Agriculture as part of the Focus on Animal Welfare network.

Types of vaccine

Vaccines are divided into recombinant vaccines, live vaccines and inactivated vaccines (killed vaccines). Recombinant vaccines are injected into chicks using a needle at the hatchery and provide lifelong protection. Live vaccines are administered via drinking water, as a spray or as eye drops, whereas inactivated vaccines are administered via a needle.

Correct use of vaccines

Effective vaccine protection is only achieved if the vaccine is used correctly, according to Dr Düngelhoef. When vaccinating via drinking water, it is important to ensure that only clear water without additives is present in the pipes for at least 24 hours prior to vaccination, as residues of disinfectants, for example, can damage the vaccine. For this reason, it is also necessary to wear clean/new disposable gloves for every vaccination. The vaccine must be stored in the fridge until the day of vaccination. It is recommended to carry out the vaccination early in the morning, as the birds are most thirsty at this time of day. It is important to ensure that the flock is allowed to drink two hours beforehand, so that the vaccine is taken up sufficiently, evenly and within two hours by the hens. This can be checked using dyes in the vaccination water.

Spray vaccination is used for respiratory pathogens. A wide variety of sprayers are available for this purpose, each requiring different amounts of water. The younger the birds, the less water is required. For spray vaccinations to be effective, the flock must be in good general health. This ensures that the young hens’ immune systems can respond effectively to the vaccination. Due to the risk of evaporation, it is recommended that vaccination be carried out in the morning during the height of summer. Furthermore, Dr Düngelhoef recommends reducing ventilation in the house. To ensure all birds are reached, they should be kept close together in crates, cages or aviaries. One variant of spray vaccination is eye-drop vaccination, in which a specific amount of vaccine is applied directly into the eye. This method is primarily used for vaccinations against mycoplasmosis and infectious laryngotracheitis.

For coccidiosis vaccination, Dr Düngelhoef favours a method in which the vaccine is administered together with a red-coloured gel onto the yellow plumage. The chicks peck the gel out of each other’s plumage orally, as it looks very attractive to them. According to Dr Düngelhoef, the chicks must have contact with their droppings for around four weeks after vaccination, as these contain vaccine coccidia. In this way, new vaccine coccidia are repeatedly ingested by the chick over several reproductive cycles, and reliable immunity develops. When rearing on perforated floors (e.g. in aviaries), paper liners must be used and remain in place throughout the entire treatment period to ensure the uptake of the vaccine coccidia. In floor rearing, however, the chicks have sufficient contact with the litter and their droppings.

It is also advisable to carry out disinfection against coccidia during the service period.

Inactivated vaccines are administered via a needle into the upper third of the sternum. Ideally, vaccination should take place at least two weeks before the birds are moved to their new housing, as the birds may be weakened for up to a week after vaccination. Every needle injection is stressful for the bird, so ‘as few vaccinations as possible, as many as necessary’, emphasises Dr Düngelhoef. The vaccine should be warmed to 20–25 °C in a water bath shortly before vaccination. The vaccination equipment must be sterile and the vaccine must be shaken regularly. The needles should be changed after every 1,000 animals.

Smallpox vaccination is a special form of needle vaccination. A distinctive feature is that the live vaccine must be injected into the skin at the site where the smallpox lesion forms (intradermal vaccination) using special needles. It is important that the needle is dipped into the vaccine and moistened with it before each vaccination. The needle is inserted into the featherless wing membrane, so that the vaccine does not get caught in the plumage. It is important with this vaccination that the cold chain is not broken; therefore, the vaccine must be kept refrigerated until vaccination and then administered within two hours.

Vaccination recommendations for pullets

Author: Viola Erfkämper, North Rhine-Westphalia Chamber of Agriculture