Fact – The goal of every administration of live vaccine is to ensure that the overwhelming majority of the birds have primary contact with the vaccine while it is in an active state. Failure to effectively gauge the correct stock solution leads to a combination of reduced protection and the possibility of lateral spread within the house. We do not want lateral spread, as this can cause reversion to virulence of the vaccine strain with certain live vaccines, and can contribute towards a performance dip in laying hens.
We have worked extensively on refining the perfect vaccination techniques with years of tongue stain testing in all poultry housing environments. By using the correct amount of stock solution calculated to the appropriate amount of ml per bird, I have recorded up to 97% of the sampled birds receiving an effective dose. This is achieved by understanding the birds drinking habits throughout the day and refining the vaccination process to accomplish the highest vaccine take.
Fact – The greatest challenge to effective administration of live vaccine in the field is water quality. Any chlorine present in the water will rapidly destroy live vaccine, and even in chlorine free water, the material used in the production of poultry drinker systems and their construction leads to an environment that is permeable by chlorine and hydrogen peroxide, which will negatively affect any live vaccines. The vaccine is also impacted by heavy minerals such as Iron and manganese building up within the water lines. The key ingredient used in Aviblue is Sodium Thiosulphate, this reacts with residual Chlorine and Hydrogen Peroxide, rendering them harmless.
The PH of the water also plays a pivotal role in how long the vaccine is viable for, water stabilisers help stabilise the PH to a 6.8-7.2, which allows for an optimal environment. Quite simply, Aviblue usage is a must for effective drinking water vaccinations. The usage rate required is 1 cap per 200 litres of water consumed, so a 2% Dosatron stock solution requires 1 cap per 4 litres and a 1% Dosatron requires 1 cap per 2 litres.
Fact – For some of the disease facing modern poultry, such as ILT, TRT, ND and EDS, further vaccination after the critical rearing period is not possible. However, for high prevalence virus’s, in the case of Infectious bronchitis, we are looking to keep the bird fully protected throughout the laying period. It is important to understand that it is the cell mediated immunity that is vital, this is what allows the birds to have the minimal interruption to their laying performance should a field challenge appear on the site. The cell mediated immunity that is stimulated by the use of live vaccines begins to wane after 6 weeks and has near fully gone by 10 weeks. The second crucial factor is that IB is simply a Coronavirus, and similar to the human challenge we faced, it is the secondary bacterial infection that is the primary cause of mortality.
An IB challenge opens the door to E. coli, the need for antibiotics and Mycloplasmae issues. The profitability of a flock and the protection of the flock’s health are indelibly linked. Hence vaccination every 6-8 weeks with the correct strains has become a cornerstone to many successful flock health plans.
Fact – The key breakthrough in overcoming the Gumboro challenge of the 1980’s, which ravaged the industry, was when we purchased food dye and David Hodson Snr. realised that there is NO mixing of vaccinated and non-vaccinated water in the water lines; as the water systems are pressurised, when we engage the Dosatron, the residual clear water in the lines is pushed to the far end of the house. A drinking system in a Big Dutchman system can have no water coming out of the nipple lines yet will still have 100ml per metre sitting below the nipple level in the water line. When we engage the Dosatran this is equivalent to 10-15 litres per line minimum if the birds have been allowed to drink the system “dry”. This leads to a significant proportion of the birds at the end of the house being unvaccinated. Every single line needs to have vaccinated water visible at the end of the line, without question. Failure to do this leads to up to 40% of the birds not receiving vaccine.
Fact – The above is something I encountered much more 5-10 years ago, however I still come across this argument and I think it can be broken down by firstly asking in human populations we encounter two periods where vaccine is considered vital, firstly when young, and secondly when older and immunocompromised by the rigours of life. A successful flock is one that reaches the end of the laying period with minimal mortality, and as we know Infectious Bronchitis prevention can only be completed optimally with cell mediated immunity. The use of Live E. coli vaccines in the laying house has been a true step forwards for laying performance, and the repeated intervention throughout lay, done pro-actively, has contributed to reduced mortality and a healthier more productive hen.
When I first started in the industry, a great friend and excellent Egg Farmer Duncan Priestner said something that stuck with me. He explained that the greatest issue as birds aged was a reduction in eggshell integrity, more so than mortality. If we are taking a flock to 80+ weeks, then those last 20 weeks can be torrid if we have lost our eggshell quality.
It’s an escapable truth that peak performance and longevity require a disease free environment, and to achieve this, excellence is the requirement in every aspect of vaccination. For complete support in all aspects of vaccination and flock health for your farm, it is our duty to help and support with on farm training and technical expertise.