Like many of the processes in poultry farming, bird performance is tied to getting the basics right.
The inactivated vaccine administration at point of lay is no different, with a well-executed treatment conferring protection from disease and no doubt smoothing the transfer from rearing unit to laying farm.
During the rearing phase, replacement pullets receive regular live vaccines, mostly through drinking lines and as a spray.
Often these treatments act as primers for the final vaccination at point of lay.
It is this final, inactivated, multi-vaccine given by injection at 16 weeks that is critical to ensure disease immunity lasts throughout the laying period.
Preparing for vaccination
John Wortley, vaccinator at AJM Hatchery Services, says farm managers and their staff can do a great deal to prepare birds and houses for a smooth final vaccination.
Mr Wortley suggests that staff walk poultry houses regularly during the rearing period.
This gets birds used to people moving about in the flock, which can help reduce stress during catching.
Catching frames enable pens to be constructed inside the house to segment the flock.
This allows catchers to push small numbers of birds to the catching area and reduces distress and the risk of smothering.
Before beginning the job, it is important to ensure there are plenty of frames for the number of birds and shed space, Mr Wortley explains.
He brings his own bespoke metal vaccinating tables, but often the farm will need to prepare an area for the vaccinating team.
Metal trestle tables are preferable as they are more easily cleaned and offer better biosecurity, but clean wooden tables will suffice.
Only healthy and fit birds should be vaccinated – those unwell or in poor condition will experience a less-than-satisfactory immune response.
Temperature also has an impact on immune response so vaccinating in the heat of the day should be avoided, particularly if birds will be waiting on trailers for transport to the laying farm.
“Vaccinating in the cool of the morning is ideal,” says Mr Wortley.
“Some producers even opt to vaccinate in the middle of the night. This has the additional benefit of vaccinating during the hours of darkness, which helps keep the birds calm until they arrive at their next destination.”
Light levels in houses should be dimmed as much as possible several hours before the vaccinating team arrives, to help settle the birds before catching.
Shortly before catching begins as much equipment as practically possible should be raised or moved out of the way of catchers and vaccinators.
“We know it’s not always possible to move every piece of equipment, but when you have drinking or feeding lines still down the birds can crush themselves up against them, which is not an ideal situation. We’ve seen birds lost this way,” warns Mr Wortley.
Where vaccinating tables are set up will depend on the space available in the house, the temperature and the time of day.
If inside the house, head torches may be helpful to provide good working visibility without increasing overall light levels in the house.
Catchers should use red lights on torches to avoid spooking birds.
Using pens to segment the flock within the house will allow catchers to push small numbers of birds to the catching area.
A catcher or staff member should remain in the pen area to keep an eye on the rest of the flock and prevent birds crowding together.
Similarly, a catcher should remain in the catching area while birds are pushed forward, continuously walking through the flock to keep birds moving.
Mr Wortley stresses the importance of bird control in the house.
“When birds are pushed forward they can very easily get spooked and pile up in the corners as they try to move away from catchers, and when this happens there is a very real risk of smothering and bird loss.
“All units should have someone to keep the birds moving around and specifically out of the corners and away from equipment.”
A good catching team is vital. To avoid damaging the birds, they must be caught in a quiet and calm manner, by two legs, and with no more than three birds carried in each hand.
Catchers should be aware of the type of vaccination being given and where this is administered on the bird.
They should then present the birds to the vaccinators accordingly.
For breast injections birds should be laid flat on the table, breast side up, with the head facing the vaccinator.
For leg injections birds should be presented in the hand, with heads facing the floor.
Catchers must keep hold of both of the bird’s legs at all times.
“The majority of injectable vaccines will be administered by professional vaccinators,” says Gavin Kelly, avian manager for the UK and Ireland at Merial Animal Health, “but it is useful to know how and where vaccine should be placed, and the type of equipment that will be used.”
Depending on the number of vaccines that need to be administered, vaccinators may use single or double vaccinating guns.
New, pneumatic guns, reduce hand fatigue for operators and are accurate and fast.
For breast injections (pictured above), with birds lying flat on the table, the vaccine is placed horizontally into the deepest part of the breast muscle from head to feet, avoiding the thinner areas at the side towards the tail-end.
For leg injections, with birds hanging vertically, vaccine is placed into the leg muscle in a downwards direction from feet to head.
Vaccinators should vigorously shake vaccine bottles from time to time during the process to ensure the contents are fully mixed.
Bottles should remain in an insulated box until they are required.
Empty vaccine bottles and used needles must be disposed of as clinical waste and not in general farm waste.
Post vaccination, it is good hygiene practice to clean the syringes as soon as possible.
This can be done by putting hot water through the syringe. Mild detergent may be added but must be thoroughly rinsed out afterwards. Steam sterilise the syringe parts and then allow them to air dry.
Finally, farmers must record the type of vaccine, batch number, expiry date and date of vaccine administration in the farm’s medicine book.
Health and safety
Hands should be washed thoroughly after handling vaccines or equipment.
Any spillages should be cleared up promptly and disposed of as clinical waste.
“It isn’t common for vaccinators to accidentally self-inject, but it does happen, and I’ve even managed to do it myself,” says Mr Wortley.
In the event of a vaccinator or catcher being accidentally injected, they should immediately be taken to the nearest accident and emergency department.
All vaccinators and catchers should carry a card with instructions of what to do in case of accidental injection.
This card should be presented to medical staff on arrival.
Mr Kelly adds: “All vaccine bottle labels carry details of the contents, including any oil-based adjuvants, which are usually the main concern with accidental injection.
“If you are in any doubt you should call the manufacturers’ helpline which is marked on the bottle label”
Vaccine will normally be ordered by the farm vet on behalf of the producer and delivered directly to the unit. Merial Animal Health’s Gavin Kelly offers some tips
- On delivery, inactivated vaccines should be stored in a clean fridge at a temperature between 2C and 8C. Freezing can damage vaccines, so check the fridge temperature with a thermometer and make sure to keep vaccines away from the backplate of the fridge to avoid freezing.
- Injecting cold vaccine straight from the fridge can stress the birds and result in a poor immune response, so it is advisable to remove the vaccine from the fridge for a period of time prior to application.
- Most vaccinating teams will supply needles. If not, check there is a sufficient number of sterile needles of the correct size and gauge required for the vaccines.
- Change needles if damaged and when changing to a new bottle of vaccine.
- Vaccines should be carried around site in clean, insulated boxes.