“A laying site must have control of IB, it is the door through which E.coli enters”
Infectious bronchitis has a myriad of effects on the birds physiology, but the key areas for our laying site is the reduction in egg quality, reduction in production, increase in secondary infections such as E.coli, MG and MS, and the possible need to intervene with antibiotics.
With the exponential growth of the free range market we have seen an increase in the occurrence of IB, chiefly IB793b is the cause of many field challenges, with IBQX still present. The most effective means of controlling IB is using live vaccines, but with that comes the technical aspects of ensuring that this incredibly delicate vaccine successfully reaches the bird in its live state.
Should the vaccine be killed by incorrect storage, exposure to Chlorine levels as low as 0.02ppm in the drinking water – work by Dr. Jordan of Liverpool University in showed a reduction in titre (vaccine strength) of 100 times in the space of 1 hour at .02ppm. To consider how important Dr. Jordans work is, standard tap water has .2ppm-.6ppm and farm water chlorination can see 2ppm of Chlorine Dioxide, which 2.6 times for effective than chlorine, thus making any IB vaccine given in the presence of these sanitisers ineffective. Water stabiliser is a must, sodium thiosulphate nuetralises chlorine and stabilises PH levels to neutral. Aviblue at 1 cap per 200 litres of water consumed is essential, this has been proven repeatedly in both lab and field environments.
Once the vaccine has been prepared, what we are always seeking in a water route vaccination is the highest possible level of bird uptake. Over the last 40 years we have done extensive work in this area, understanding and refining the process through constant testing. The use of tongue staining trials, in which a strong Aviblue concentration is used, and once the calculated stock solution is consumed a physical check of 100 – 200 birds is done throughout the house. The last run of trials showed a 98% success rate for vaccine uptake.
Quite simply, the water lines must always be primed until the dye is present at the end of the lines, and enough water must be allowed to ensure a near complete uptake of vaccine for the shed. To do this vaccination is required after the birds have gone through a thirsted period, such as overnight. The stock solution must be what a thirsted bird will drink over a 2 hour period.