12 minute read
Spring turnout: Your guide to worming responsibly
Livestock Spring turnout: Your guide to worming responsibly
As we prepare to turn calves out to pasture, livestock editor Sarah Kidby spoke to Norbrook veterinary advisor Douglas Palmer for advice on available worming strategies, and how to reduce the risk of resistance.
As AHDB Dairy suggests that dairy heifers take an extra three months to reach breeding weight when burdened with gastrointestinal parasites, at an extra cost of £260/head, managing this risk ahead of turnout is a priority.
In order to calve down at 24 months, dairy calves need to meet growth rates of 700g/day to bull at 15 months. Anything that slows this process down will naturally increase costs and reduce overall lifetime productivity.
Although resistance is well recognised in the sheep industry, it is less widely reported in the cattle sector – however, lack of data means it could be a bigger problem than we realise, and it’s important not to be complacent.
“Probably the most economically signi cant worm species would be Ostertagia ostertagi in cattle, but where resistance has been found, it has been identi ed more with Cooperia species, which may be less pathogenic,” Mr Palmer explains. “We need to be using our medicines more sustainably – not relying on anthelmintics but incorporating other strategies to control worms. Ostertagia resistance has been seen in other parts of the world so we do need to be careful.”
Diagnostic testing
One thing Mr Palmer believes could be utilised more on farm is monitoring weight gain for targeted selective treatment. He recommends weighing every 4–6 weeks to check the growth rate is being met and if not – assuming there is no other obvious cause – consider whether that individual needs worming, as parasite burden is one of the more signi cant causes of poor weight gain.
Alternatively, monitoring pooled faecal egg counts (FECs) every 3–4 weeks in young calves can be used to identify groups of calves carrying heavier gut worm burdens.
The di culty with both options is tting these in with lungworm – which needs relatively fewer worms to cause disease but can mature on pasture within a week, so farmers can get caught out when doing selective treatment and faecal egg counts. “The way to help avoid this is to vaccinate for lungworm,” Mr Palmer notes.
Vaccinating calves for lungworm should be completed before turnout, then targeted selective therapy or FECs can be started around 3–4 weeks later. If these are clear, repeat in another 3–4 weeks and treat if worm burdens are rising.
How to reduce the risk of resistance
Ensuring drugs are used correctly and applied in the right way is important. “The advice within the industry is always to dose groups of animals based on the heaviest in the group which I always say is great advice as long as the heaviest in the group isn’t twice the weight of the lightest. If you overdose a drug there’s a chance of a toxic reaction, and overall you use more anthelmintic, adding to the cost,” Mr Palmer explains.
“Pour ons should be applied to cattle midline down the back on the attest part of the back between the withers and the tail head. In order to do that properly, the animal will probably need to be restrained.”
Checking that wormers have been e ective with follow up FECs is another area that could be improved upon.
Co-grazing mixed ages is another strategy. “Beef calves are always co-grazed with their mums, whereas dairy calves – which are typically higher stocked and more intensively grazed – don’t have mum going around hoovering up all the extra larvae,” Mr Palmer explains. “And the mum represents an in refugia population of worms that are not exposed to the drugs as well because she doesn’t get treated. This helps maintain the worm's susceptibility to anthelmintics.
“Co-grazing in a rotational system with older cattle or sheep, especially with calves at the head of that rotation so they’re constantly going onto clean new grass. The di culty is when you run out of that and start to bring them back round again. They’re then back on same pasture three weeks later and the worms have had a nice easy time maturing, so that’s where rotational grazing lets you down a bit.”
What actives are available and when should they be used?
The three groups are – group one: benzimidazoles (white); group two: levamisole (yellow); and group three: macrocyclic lactones (ML – clear), for example ivermectin, doramectin etc.
Drenches are perfectly good options but more di cult to administer and have no persistence, Mr Palmer explains. The bene t is reduced risk of inducing resistance, but when you’ve got a worm problem you might nd you have to administer it every month. Whereas ML products have some persistency – some ivermectin pour ons have a two-week persistency for Ostertagia ostertagi.
For ivermectin products, Mr Palmer says: “While traditionally calves would have been drenched at three, eight and 13 weeks, it is now reasonable to turn out, do FECs and if the levels start to go up, give the rst dose, then check again 4–5 weeks later – keeping a close eye on lungworm, having hopefully vaccinated beforehand.”
Doramectin is the active substance in Norbrook's Taurador product, and it has a ve-week persistency for Ostertagia ostertagi. “Traditionally it was administered with an eightweek treatment interval, but we’ve tried to move away from that [...]. The more responsible thing to do is turnout, wait three weeks, do a FEC and look at treatment from there.”
Mr Palmer adds: “Then there is the moxidectin, particularly the injection which was really aimed as a one-o shot. And the benzimidazole pulse release bolus, which is a pulse therapy so the calf gets a pulse every three weeks, with a gap in between where the calves get a bit of exposure to the worms. As a benzimidazole, there’s no evidence of resistance in the UK as yet, but the downside is this is relatively more expensive.
“By late summertime, if you’ve had to use quite a lot of say macrocyclic lactones, it would seem reasonable to think about trying to put in a di erent active ingredient at that point, like a levamisole or a white wormer to try and reset any early resistance developing,” he continues.
For more worming advice ahead of turnout, speak to your vet or RAMA. For details on Norbrook farmer meetings on responsible use of medicines, contact Norbrook or your local vet. FG
Having an e ective cleaning and disinfection programme is essential in modern calf house management, to reduce the risk of disease. Evans Vanodine provides advice on a controlled disinfection programme.
As a thoroughly cleaned and disinfected pen aids the health of calves, it is therefore important that housing management systems are optimised in order to prevent stress and limit the calf’s susceptibility to disease.
Attention to detail and an e ective cleaning and disinfection programme are essential in order to maintain high standards and reduced mortality rates, however, inevitably calves will be exposed to viruses, bacteria and parasites in their environment, which are capable of causing scours, respiratory problems or other diseases.
Through the use of a controlled disinfection programme, the number of infections and organisms to which the calf is exposed are reduced. The health of calves should be a priority, as how they are looked after in early life determines their outcome, which can essentially save both time and money.
Coccidiosis and cryptosporidium – both diarrhoea-causing infections that are common in young calves, and can be fatal – are hard to treat. However, prevention through a good cleaning and disinfection programme is key to reduction.
Evans Vanodine has tested and found the following system to be e ective in destroying the oocysts that enable the infections to spread.
After all animals and portable equipment have been removed from the pen: • Remove any organic material • Apply Target Powergel at 1:14 through a foam cleaner or low pressure washer (less than 70 bar). Allow a one-hour contact time before rinsing o thoroughly with clean water and allow to air dry. • Spray all areas thoroughly with a solution of GPC8 at 1:35, at a rate of 300ml per square metre. For best results apply as a foam • Re t portable equipment and allow to air dry. Protective clothing and equipment (PPE) must be available for all personnel. It is essential that the correct clothing and equipment is utilised when using chemicals to clean and/or disinfect.
Evans Vanodine is an independent British family business that has been sharing expertise since 1919 and operating within the agricultural industry since 1962.
It is a BSI registered company which operates to ISO 9001 for quality compliance and ISO 14001 for environmental compliance. The company produces an extensive range of cleaning and disinfection products for multiple applications within the dairy and wider animal health sectors.
On-site in Preston, it houses three laboratories which ensure its products are of the highest quality, comply with industry regulations and meet any claims made.
The product range is complemented by the hands-on approach o ered, from technical support and farm visits, comprehensive literature, support materials and micro pro les, to in-house testing facilities.
To nd the full range of Evans Vanodine products visit the website: www.evansvanodine.co.uk
To nd your local Evans Vanodine distributor, contact sales@ evansvanodine.co.uk FG
Coccidiosis and Cryptosporidium, both diarrhoea causing infections common in young calves, can be fatal and are hard to treat. Evans Vanodine recommends using Target Powergel and GPC8 in your cleaning and disinfection programme and following our calf pen cleaning routine to help reduce cases. This routine has been tried and tested and is shown to be e ective in destroying the oocysts which enable infections to spread.
EFFECTIVE IN DESTROYING OOCYSTS
Find out more and read the full article on our website.
Evans Vanodine
T: +44 (0)1772 322200 E: sales@evansvanodine.co.uk www.evansvanodine.co.uk
Cutting corners “will not improve calf rearing e iciency”
This was the key message from a practical calf-rearing webinar, hosted by Volac as part of Great British Calf Week in February.
Although many units may not be rearing calves in perfect buildings, there is always room for improvement, said dairy farmer Abi Reader.
The farm recently took on a new calf rearer, who despite having no prior farming experience, pointed out how many corners were being cut and requested a whiteboard for sharing important rearing protocols. Abi said this “works brilliantly” and the farm is now far more consistent.
The new recruit also asked for some simple weigh scales so that inputs could be measured accurately and consistently. While these may be small changes, they add up to a better ow of communication and make life easier for all involved, Abi added.
Some of the biggest gains have come from improving colostrum feeding protocols. Abi advised using a refractometer to test colostrum quality and, when freezing colostrum for use later, always store the best quality (ideally in small, recycled plastic bottles). Or, mark it up as potentially poorer quality if you are really short.
Even in less-than-ideal calf accommodation, calves must always be as warm and dry as possible, and cleaned out regularly using lime if necessary to soak up moisture. “I’m also keen on calf jackets and heat lamps when the weather is cold,” she added.
Volac R&D manager Dr Jessica Cooke, stressed the importance of feeding enough milk during the winter months. “For a calf less than three weeks old, you need to step up the level of milk solids by 100g per day for every 10°C drop in temperature below 20°C. [...] This can be achieved by either increasing the volume fed, or by increasing the mixing rate.”
Assuming colostrum management and feeding protocols are sound and calves have access to fresh water, roughage and a palatable starter concentrate, Dr Cooke said feeding up to 900g (750g minimum) of calf milk replacer daily will allow you to meet optimum rearing targets. The peak milk allowance (6–8 litres per day in maximum 3-litre feeds) should be reached by two weeks of age.
Calving heifers at 24 months of age is known to be associated with increased survivability and lifetime milk yield. “To achieve this goal e ciently, you have to maximise growth throughout the milk feeding period; use a whey protein concentrate-based milk replacer (e.g. based on Imunopro) to support better calf growth, development and health; and encourage early solid starter feed intake to ensure good, follow on growth rate post weaning.
“We also encourage all calf rearers to monitor performance too – and if you are always rst breeding your heifers at 55–60% of their mature body weight, at 13–14 months of age, you are well on the right track towards a more sustainable dairy farming system.” FG
Number 1 for 50 years
We understand
what it takes to rear strong healthy lambs
50 YEARS of
ESTD. 1970
As pioneers in the development and manufacture of high-performance milk formulas, Volac created the first instantised milk replacer for lambs: Lamlac® . For over 50 years we have taken our passion for animal nutrition and continued to research formulation and processing developments, ensuring Lamlac® remains the UK’s number one selling formula. We understand, we’ve done the science.
lamlac.co.uk
MOULTON
M MBUCK RAKES BR1 BR2 BR3
MOULTON PUSH OFF BUCK RAKES
Very heavy duty push off buck rakes, fully flat back design, for use on rear or front linkage. Our buck rakes can be used on telehandlers using an optional adaptor frame. Manufactured in 3 standard sizes – 12, 14 & 16 tines. Fitted with heavy duty conus 2 tines, and double side tines.
Specifications:
BR1 12 tine 2400mm overall width empty weight 690kg BR2 14 tine 2800mm overall width empty weight 730kg BR3 16 tine 3200mm overall width empty weight 770kg
Smisby Road, Ashby de la Zouch, Leicestershire LE65 2UE www.moultonfarmmachinery.co.uk Phone 01530 567040Trade enquiries welcome Fax 01530 412512
