Remote control
How farmers can prepare for the summer vaccination season
WITH the weather beginning to warm up, many UK fish farmers will be looking ahead to the summer vaccination period. Throughout the summer season, MSD Animal Health will be partnering with fish producers to deliver effective vaccination programmes.
‘Although we are facing unprecedented times, as a team we will continue to support our customers in the best way we can,’ said Liam Doherty, MSD’s technical and account manager.
‘We will achieve this by maintaining a regular dialogue via telephone calls and online, to help provide training and continued product support.
‘While we may not be able to visit farmers in person at the moment as per our normal approach, it’s important the advice and processes are still adhered to despite everything going on.’
Initially, before carrying out any vaccination, it is really important to abide by the guidelines on the product datasheet of any vaccine, said MSD.This includes information on how to store the vaccine, and when it should be administered to fish.
‘When vaccinating, fish stock must be healthy.This includes making sure that the fish are the correct size for vaccination,’ said Docherty.
‘The product datasheet will specify the minimum size fish should be ahead of vaccination, and failing to follow these guidelines could result in adverse reactions in the fish.
‘In the past, some farmers have found the vaccinations ineffective simply because the fish have been vaccinated at the wrong time.’
As well as healthy fish, water temperature can significantly impact whether the vaccination will be effective, and how long the fish need after vaccination to build up immunity.
Water temperature should not be too high as this can increase the risk of internal adverse reactions, as Claudia Marin, from the MSD Animal Health aquaculture team explains.
‘One of the most critical aspects of fish vaccination during the summer months is ensuring onset of immunity prior to seawater transfer.
‘This is a period of time after the vaccination during which the fish are held at a specific temperature so that they develop a strong immunity prior to being exposed to the challenge.
‘The MSD Animal Health vaccine,Aquavac PD3, requires 500 degree days after vaccination for SPDV and Aeromonas salmonicida and 540 degree days after vaccination for IPNV. So, if the water temperature is 10oC, you’re looking at 50 days for the 500 degree day development to build up enough immunity in the fish.This means that fish will remain in the tanks for 50 days, before being transferred to sea water.’
She added:‘Pay close attention to the external environment during summer as this could influence your water temperature.’
In some cases, both Docherty and Marin have found that when there has been insufficient time to allow immunity to develop and fish are moved to seawater where these challenges are present, protection may be suboptimal.
This pressure is particularly significant in flow-through systems as there can be large fluctuations in water temperature when it is filtered back into the water source.
Although not visiting farms now, the team would normally be on-site during the vaccination event to provide an auditing service.
‘At the moment, we will be offering support over the phone and online; however, under normal circumstances we would aim to visit the farm for at least one day of vaccination to ensure it is being administered correctly,’ said Docherty.
‘During the visit, we would measure the accuracy of vaccine administration, and check that the machine, or vaccination team is properly managed and maintained.’
Fish Health App
But, he said, all MSD customers have access to the company’s vaccination app, used to collate immediate graphs on vaccination accuracy.
‘The Fish Health App will then inform staff on whether the accuracy of a machine is beginning to wane, so that it can immediately be adjusted.
‘If the farm is hand vaccinating, you can audit individuals and input this data into the app, which will again immediately produce pie charts identifying the optimal point of vaccination, acceptable points, and fails.
‘In the long run, poor vaccination can cause huge financial implication due to damaged fish being downgraded at harvest. How well the vaccination procedure has been carried out will significantly impact this.’
He added:‘If vaccination is inaccurate, it can deposit the whole vaccine dose into the fish body wall, which will effectively turn into melanin over time.
‘These parts of the fish will then have to be cut out and discarded. So, for example, if you had a 10 per cent downgrade level on 300,000 fish, the level of loss is huge.
‘In the lead up to summer vaccinations, we recognise that fish farmers will be facing a number of difficult challenges, and many of them out of their control.
‘We would like to reassure our customers that the team is available to offer remote support and advice.
‘We are determined to continue offering technical support despite current adversities, and look forward to resuming farm visits as and when we are able to.’.
We are determined to continue offering technical support despite current es” adversiti