Sheep farmers can make use of a newly launched parasite web-based forecast as temperatures look set to rise, and the risk of nematodirous increases.
Sheep farmers are being urged to keep an eye on parasite forecasting web-based services – including a new localised service called Parasite Watch – as advisers warn rising spring temperatures will trigger large numbers of larvae to hatch in the next few weeks.
The main focus remains on nematodirous. This disease sees young lambs ingest large numbers of gut worm larvae deposited at pasture a year earlier which go on to destroy the lining of the gut. This develops in to black diarrhoea or black scour, as it is commonly known, leading to increased lamb mortality, farmers are warned.
Independent sheep adviser Kate Phillips says: “A number of factors are coming into play. A large lamb crop has been forecast helped by reasonable weather conditions, but this is being compromised by poor grass growth. Many report grass is growing back into the ground rather than up to the sheep.
“In some areas that could impact on lamb growth rates, particularly if ewes were not adequately supplemented ahead of lambing. Under performing lambs are more likely to succumb to infection.
She adds: “We can expect mass hatching [of parasitic larvae] as day and night time temperatures average 10degC. Lambs at greatest risk will be those grazing fields which carried ewes and lambs last year.”
The combination of localised weather and temperature data allows sheep farmers to be forewarned of parasitic challenges. Where Parasite Watch differs from other services, such as those operated by NADIS, SCOPS and Bristol University, says David Armstrong – national veterinary manager for ruminants with animal health company Zoetis which has launched the service – is the use of 14 commercial sheep farms selected as ‘intelligence hotspots’ which are monitoring and reporting on parasitic challenges as they arise.
Mr Armstrong adds: “This is real world, real-time data collected by Zoetis vets who will provide commentary and early warnings of outbreaks. The focus will be on four key parasitic types being gastrointestinal worms [estimated to cost the industry £84 million a year in losses], nematodirus, liver fluke and flies.
Like the existing providers, the new service marries up the on-farm information to weather data gathered from 140 Met Office stations nationwide. This information helps assess localised risk of parasite activity which can be used as an early warning system to alert other sheep farmers.
Steps to control parasites by sheep farmers range from good pasture management to selecting an appropriate parasite control in conjunction with an animal health suitably qualified person and/or the farm vet, it is suggested.
Mr Armstrong says: “Given the market environment we know farmgate price and profits are being questioned. That may lead to rash decisions being taken on-farm as whether to treat lambs or not. Low [parasitic] disease levels on-farm in 2015 does not mean farmers got away with it [where stock was not treated]; there is concern they may think it can be done again.”
Mrs Phillips puts this year’s risk into context, saying: “Parasitic challenge will increase dramatically should the weather improve quickly as lambs will start to take in significant quantities of grass. The ideal is to have young lambs on clean grass.
“Weighing lambs regularly will help identify those which are under-performing and those which may benefit from being treated. Faecal egg counts undertaken at three to four week intervals will help highlight whether treatment is necessary and, importantly, has been effective.
She adds: “Given the mounting evidence of resistance to anthelmintics, farmers should only use products which are at least 95 per cent effective in the individual flock. If they are not then speak to your vet now to discuss your options.”
To get effective protection against parasitic challenge farmers are urged not to assume the results for one batch of lambs is indicative of all groups on the same farm. Test several batches to get a broader picture, urges Mrs Phillips.
She adds: “Likewise, be aware the high carry-overs of mud snail and liver fluke, the latter may require ‘at risk’ flocks to give an 1-BZ wormer to lambs at four to six weeks old to prevent an outbreak, which will also present challenges in the coming weeks.
“Nematodirus can often occur with coccidosis, so it is best to be prepared and get a thorough diagnosis first. Also remember early-born February/March lambs will be losing their maternal antibodies and will be more exposed to disease challenges.
“The lamb market is likely to be challenging again in 2016, so do not be tempted to cut costs in the wrong places.”
Parastite Watch from Zoetis uses 14 commercial sheep farms selected as 'intelligence hotspots' which are monitoring and reporting on parasite challenges as they arise.
The Parasite Watch host farms have agreed to share observations via @sheep_farmers on Twitter.
To read the Parasite Watch advisory blog, visit liveuk-livestockfarming.ztsaccess.com/