BHC Newsletter Autumn FINAL


ANIMAL HEALTH IRELAND Contributing to a profitable and sustainable farming and agri-food sector through improved animal health











Beef HealthCheck

Animal Health Ireland, 4-5 The Archways, Carrick-on-Shannon, Co. Leitrim, N41 WN27

BEEF HEALTHCHECK PROGRAMME UPDATE By the end of September Beef HealthCheck results for almost 650,000 animals had been reported to the ICBF database

A series of Beef HealthCheck events took place at the end of June and early July. These events were joint ventures between Animal Health Ireland, Teagasc, and Meat Industry Ireland. The theme of the events was ‘prevention is better than cure’, an old adage but one that is very relevant today with the increased focus on antimicrobial resistance and minimising the use of antibiotics on farms. On each farm the farmer and their vet spoke about health in the herd, problems encountered, how these were dealt with and preventative measures in place to keep animals free of disease. The five events were held on several different farm systems, including finishing units, where buying in policies and the management of new arrivals to minimise stress and prevent disease were discussed, and suckler farms, where calf health was reviewed. On all farms the key take home message was that healthy cattle need fewer medicines and good husbandry and preventative measures will reduce antibiotic usage. With a new Animal Health Ireland leaflet ‘Neospora caninum- A guide for Farmers and Vets’ now available, vets discussed this leading cause of abortion in Irish cattle. How to investigate an abortion was outlined and the importance of submitting samples to laboratories highlighted. Control measures for farms with Neospora problems and prevention strategies for herds free of the disease were summarized.

Rebecca Carroll presenting at the Beef HealthCheck event in Edenderry.




Advisors from Teagasc discussed the use of faecal egg counts to guide the use of anthelmintics on farms. Faecal sample results from research farms and recent results from the host farm were reviewed. Faecal samples showed that spring-born sucked calves generally had no worms or low burdens and wouldn’t require dosing for gutworms until later in the grazing season. Farmers heard that lungworm is unpredictable and can cause problems before lungworm larvae are seen in faecal samples, so all cattle at grass should be monitored for coughing. A considerable number of farmers who attended the events are receiving Beef HealthCheck reports for slaughtered cattle from their participating meat plants. At the events examples of the conditions that can be found in the livers and lungs of slaughtered cattle were shown and farmers were advised on how they can use the reports and the Beef HealthCheck online tools, available on the ICBF website, to monitor liver fluke dosing programmes, respiratory disease control and the management of finishing cattle diets. National results from the programme were reported and farmers were shown local results from their county. By the end of September, Beef HealthCheck results for almost 650,000 animals had been reported to the ICBF database. Graphs shown at the Beef HealthCheck events reported liver fluke status by county, indicated wide differences between animals going to slaughter from counties in the northwest and counties in the east. Results for heifers, steers and young bulls were also reported. Results were similar for each carcass type, although steers had slightly more liver abscesses while young bulls had slightly the highest levels of pneumonia lesions.




Biosecurity in beef herds

Donal Toolan, RVL, Kilkenny (Retired)

B efore housing is a good time to ensure that as much as possible is done to minimise the introduction of disease to the herd (bioexclusion) and to minimise the risk of spread of disease already present in the herd (biocontainment). • Weaning: Weaning should be done gradually, preferably in batches, and calves should be eating at least 1 kg/ head daily of concentrate feed at weaning time. Ideally, home-bred weanlings should be weaned several weeks before housing or sale. Castration and dehorning should not coincide with weaning and housing. If weanlings are being vaccinated, the vaccination course should be started sufficiently early so that animals are fully protected before housing or sale. • Purchased weanlings: If weanlings are being purchased, they should be sourced from as few farms as possible, and preferably from farms of known disease status. Ideally, they should be moved directly from farm-to- farm, should be weaned at least two weeks prior to sale and eating concentrate feed, and should not have been castrated or dehorned in the previous four weeks. They should be fully vaccinated against clostridial and respiratory diseases. If weanlings are being assembled from multiple sources, they should be mixed outdoors for a week or two before housing. • Lungworm vaccination: For calves born in the autumn, vaccination against lungworm (hoose) prior to turnout in spring should be considered. • BVD: Any PI animal (persistently infected with BVD virus) remaining in the herd should be slaughtered immediately. If such an animal comes in contact with animals in early pregnancy that have not been previously exposed to BVD virus, abortions or the birth of further PI animals might occur.

• Body Condition Scoring (BCS): Body condition (fatness) of cows should be assessed and individual animals needing to lose or gain condition should be identified and fed accordingly. Silage should be analysed to determine its nutritive value and advice obtained on the appropriate feeding levels necessary to ensure that cows calve at optimum BCS. • Mineral/Trace Elements: All animals should be given a suitable balanced mineral/trace element supplement. Cows should be given a precalving mineral/trace element supplement for at least six weeks before calving. Supplemental minerals and trace elements should be provided from one source only as overdosing will lead to toxicity. • Liver fluke prevention: If liver fluke or rumen fluke is a problem on a farm, the feasibility of drainage of wet areas or of fencing them off should be considered. • Housing - Ventilation: Winter accommodation should be checked to ensure that there is sufficient capacity for the numbers of stock intended to be over- wintered. Buildings should be checked to ensure that there is adequate ventilation without draughts at animal level. Allow for the growth of animals over the winter when calculating space allowance and ventilation requirements. - Isolation and calving facilities: There should be a sufficient number of individual calving boxes, depending on herd size and the compactness of the calving pattern. There should also be adequate isolation facilities for animals that are ill. The calving area should be completely separate from the isolation area.




Further information Useful information may be found in AHI leaflets on biosecurity, especially “Purchasing Stock” and “Bio- Exclusion”. A short note such as this can highlight only general principles. It is very important for every farmer to discuss these matters with their own veterinary practitioner and to get advice specific to their own farm.





Parasite control in cattle at housing

Donal Toolan, Parasite Control Technical Working Group, Animal Health Ireland

Parasites: Housing provides an ideal opportunity for treating cattle for parasites. As the animals will not be grazing for several months, they will not have the opportunity of being re- infected with stomach/gut worms, lungworms, liver fluke or rumen fluke. The Animal Health Ireland (AHI) leaflet “A Guide to Parasite Control at Housing” discusses in much greater detail all the points raised here. A short note such as this can highlight only general principles. It is important for every farmer to discuss these matters with his/ her own veterinary practitioner and to get farm-specific advice. Important points to remember are: Stomach worms - Inhibited Ostertagia larvae: During the autumn, larvae of the stomach worm Ostertagia – a cause of winter scours may become dormant for long periods (months) in the stomach wall. As levamisole (yellow drench) is not effective against these inhibited Ostertagia larvae, it should not be used at this time of year (including any combination wormer/flukicides that contain levamisole as the wormer). Benzimidazoles (white drenches) and avermectins are effective against these inhibited larvae. Liver fluke: The need for dosing for liver fluke is based on grazing history, history of previous liver fluke disease on the farm, and rainfall during the summer and autumn. The Department of Agriculture Food and the Marine issues a national liver fluke forecast every autumn but this must be interpreted in the light of previous disease history on an individual farm. The Beef Health Check programme gives useful information on the prevalence of liver fluke in individual farms. The recording by the programme of live fluke in a proportion of cattle slaughtered during the spring of 2017 indicates that adequate treatment regimes at or during housing are not in place in all herds.

• Choice of flukicide: Timing of dosing for liver fluke and the interval at which doses need to be repeated depend on the drug used – see AHI leaflet on “Liver fluke”. - Triclabendazole kills early-immature, late-immature and adult fluke. It can be administered two weeks after housing and one treatment should be sufficient for the housing period provided no resistance to the drug is present. - Closantel, nitroxynil and rafoxanide are effective against adult and late immature liver fluke. If a single treatment is being used, it should be delayed until at least 6- 8 weeks after housing. - Albendazole , oxyclozanide and clorsulon are effective against adult fluke only. If the risk of fluke is low, a single treatment in January should be effective; if high, cattle could be treated at housing and again 6-12 weeks later. • Outwintering: If cattle are outwintered on fluke- infested ground, repeat treatments may be needed during the winter to control liver fluke disease.

The need for dosing for liver fluke is based on grazing history, history of previous liver fluke disease on the farm, and rainfall during the summer and autumn.




Rumen fluke: Rumen fluke are widespread in Irish cattle but do not usually cause clinical disease. However, a few cases have been reported where serious losses (deaths) were recorded. If cattle are thriving well, finding rumen fluke eggs in a faecal sample does not necessarily imply that treatment for rumen fluke is required. If deaths or poor animal performance due to rumen fluke have been previously diagnosed on your farm, your veterinary practitioner may advise treatment for rumen fluke. There is no drug licensed in Ireland for the treatment of rumen fluke but oxyclozanide is effective . In most farms, in most years, liver fluke is much more significant than rumen fluke. As oxyclozanide is only effective against adult liver fluke and not against immature liver fluke, it is important that the timing of treatment for rumen fluke also takes into account the stages of liver fluke that is present at that time. See AHI leaflet on “Rumen fluke”. • Treatment failure: If treatments for liver fluke or for stomach/gut worms seem to be ineffective, it is important to discuss the problem with your veterinary practitioner and to have it investigated. Failure may be due to faulty dosing technique, inaccurate calibration of the dosing gun, poor estimation of live-weight or resistance to the drug employed. Resistance to triclabendazole, levamisole, benzimidazoles and ivermectins has been reported in Ireland but how widespread it is among cattle parasites is unclear. • Lice and mange: Injectable avermectins are effective against some types of lice and mange, while topically applied avermectins are effective against all types. Topical insecticides such as pyrethroids or amitraz are effective against skin parasites but not against internal parasites. For effective control of lice, all animals in a shed must be treated at the same time.

Further information Useful information may be found in AHI leaflets on paraste control which are available on theAnimal Health Ireland website or by clicking on the the leaflets below .




An introduction to IBR

Dr David Graham, Programme Manager for Biosecure Diseases, Animal Health Ireland

What is IBR? IBR (Infectious Bovine Rhinotracheitis) is a respiratory disease caused by a virus called bovine herpes virus-1 (BoHV- 1), but more commonly known as IBRV (IBR virus). Infection in adults can also cause sudden milk drop, conception failure and abortion, while in calves it may cause inflammation of the throat or nervous signs. Not all animals infected animals show obvious signs of disease (sub-clinical infection). Infection is widespread in Irish herds, with approximately 75% of both dairy and beef herds containing animals that have been exposed to IBRV. How does the virus spread between animals and herds? The virus is mainly spread directly by close contact between animals. It can also be shed from the reproductive tract, including semen, resulting in venereal transmission. Airborne spread may also occur over distances of up to 5m. Indirect transmission within or between herds can

also occur through movement or sharing of contaminated facilities, equipment or personnel. Latently infected carriers Recovery following initial infection is associated with the development of immunity, but this does not eliminate the virus. Instead, it enters a latent (sleeping) state, typically in nerve cells in the brain of the animal, which is now a latent carrier. During this period the latent carrier is not shedding virus. However, episodes of stress can lead to re-awakening (reactivation) of the latent infection, followed by shedding of the virus, creating new infections in other susceptible cattle, which in turn also become latent carriers (Figure 1). Transport, calving, lameness, nutritional stress, mixing stock and other diseases are all potential triggers for reactivation. These latently infected carriers play a central role in maintaining IBRV in infected herds, where they act as a reservoir of infection.

Figure 1: Spread of IBRV within a herd following reactivation and shedding of virus from carrier animals.

‘Apparently’ healthy latently infected carriers (antibody test positive)


Newly infected animals




Vaccines There are several IBR vaccines containing either killed or live virus licensed for use in Ireland. These are all “marker” vaccines, meaning that when used with an appropriate test it is possible to distinguish those animals that test positive due to vaccination from those that are positive due to infection. Decisions on which product and vaccination strategy to use in a particular situation should be made with your veterinary practitioner. Always read the datasheet provided with the vaccine to make sure that it is stored and used correctly, including being given by the correct route (which may be up Several European countries, or regions thereof, are officially recognised by the EU as being IBR-free, while others have approved eradication programmes underway. Animal Health Ireland is currently working with industry stakeholders to investigate options for a national approach to IBR control. In the absence of a national programme, the decision to implement a control programme in a breeding herd will be influenced by a number of factors, including herd specific goals (e.g. obtaining or protecting a high health status, production of potential AI sires and sale of IBR-free stock) and the levels of clinical and subclinical disease. Whereadecision is taken to implement a control programme, the three recommended steps are: investigate, control and monitor. Investigate: where the level of infection is unknown, strategic testing will indicate if there is no current evidence of infection, a low prevalence or a medium/high prevalence. This in turn can help when selecting the relevant control options. Control: There are 3 general principles that can be included in herd control strategies for IBR. The most suitable control strategy will vary with the herd status and should be decided under veterinary guidance. • Bioexclusion: this is an essential component of all IBR control strategies, aiming to put in place farm-specific measures to prevent introduction of infection. These should address the highest risk activities first, with a focus on introduced animals and direct or indirect contact with cattle in other herds. the nose, into the muscle or under the skin). Control: international, national and herd level

Cow with nasal discharge from IBR infection

• Culling/isolation: In herd that start with, or achieve a low prevalence of infection, this can be used remove the last remaining latent carriers. • Vaccination: complete and regular herd vaccination makes it less likely that a latent carrier will reactivate and shed the virus, and reduces the likelihood that a susceptible animal will become ill and transfer infection following exposure. In infected herds, cattle born after the implementation of effective vaccination and bioexclusion programmes should remain free from infection, resulting in an annual decrease in the prevalence of infection.




Monitoring: all control programmes should be monitored to make sure they are working. The most appropriate method of monitoring will depend on the herd type and status, but in suckler herds will most commonly involve blood testing. Purchasing for store, finishing or export markets IBR is a recognised part of the ‘respiratory disease complex’ in herds where animals are purchased frommultiple sources and mixed after purchase. Transport and mixing can result in outbreaks of IBR following reactivation of latent infection and spread to susceptible animals. Vaccination, (ideally in advance of movement or on arrival on farm), along with measures to reduce stress during transport and following arrival can help can help control these outbreaks. IBR in herds that breed bulls for A.I. Animals that have antibodies to IBR (even if as a result of vaccination) are legally prohibited from entering semen collection centres. These herds are recommended to have eradication programmes in place (if not already IBR-free). Potential AI sires should not be included in vaccination programmes and where these are in place, careful planning to prevent accidental exposure to vaccine virus is required.

Recovery following initial infection is associated with

the development of immunity, but this does not eliminate the virus. Instead, it enters a latent (sleeping) state, typically in nerve cells in the brain of the animal, which is now a latent carrier.

Further information Detailed information leaflets on IBR and herd biosecurity, along with answers to frequently asked questions are available the Animal Health Ireland website or by clicking on the leaflets below.





Nutritional management of winter finishing cattle to prevent acidosis

Brian Garry, Ruminant Nutrition Specialist, Teagasc Moorepark, Fermoy, Co.Cork

G rass silage is the predominant feedstuff for cattle in Ireland during the winter period. In winter finishing systems where conserved grass quality is low it may not be suitable for achieving sufficient weight gain to finish cattle to a suitable specification. A less expensive option for finishing cattle might include the use of concentrate in an ad libitum diet with minimal roughage. The advantages of ad libitum feeding are improved and predictable cattle performance, better kill out and quicker turnover of cattle. When planning to start feeding cattle any concentrate care should be taken to avoid digestive upsets.

Acidosis Normal rumenpH(the level of acidityof therumen)fluctuates between 5.8 and 6.3. Sub-acute ruminal acidosis (SARA) occurs where rumen pH falls below 5.8 but remains above 5.5 and clinical acidosis occurs when rumen pH falls below 5.5. Where acidosis is present, there will be an increased risk of laminitis and liver abscesses occurring. Key to any nutritional feeding strategy is to minimise the risk of this occurring. Concentrate feed should be introduced gradually to cattle, aim for 21 to 25 days to adapt cattle to their diet. Starting with 3 kg feeding rate and gradually increasing by 1.5kg every 4 days until target level of feeding is achieved, is




Feed Management Ad libitum feeding requires a high level of feed management if cattle are to achieve high levels of performance. Feed troughs should never be allowed to go below 5% of feed remaining. Cleaning out feed troughs regularly will ensure that fresh feed is available. Identifying acidosis Cattle suffering from acidosis may show obvious pain, kick at their belly, grind their teeth, go off their feed, walk with a tight, tiptoed gait or develop signs of colic. Cattle that have been off feed (due to other health problems) and start eating again may develop acidosis, and it can also oc- cur in cattle on a full energy ration that have their feeding program disrupted. Dung will become loose and bubbles will be present. Treatment Where individual cattle show mild signs of acidosis, a drench of 112 g of sodium bicarbonate in 600 ml of water can be administered orally followed by a half dose a few hours later. Cattle should be offered a diet with additional forage and reduced grain while recovering from acidosis. In severe cases of acidosis seek veterinary assistance immediately.

advised to minimise risk of digestive upsets. Avoid changing the concentrate formulation during the finishing period as this can also lead to a higher risk of acidosis. Diet formulation Finishing cattle achieving high levels of performance require a high energy diet which must also ensure a healthy rumen so that digestive upsets are limited. It is essential that the diet contains a source of long fibre, which is typically straw ad libitum (minimum 10% of total dry matter intake). A higher inclusion level should be used for silage as it contains less fibre than straw. Concentrate specification can vary depending on what ingredients are available and their relative economic value. Concentrate for all finishing cattle should be above 0.92 UFV (Unite forragere viande) per kg fed. Cereals should make up the primary ingredient in any finishing concentrate. Cereals contain starch, which promotes the growth of propionic and lactic acid producing bacteria in the rumen. While high inclusion levels of cereals are desirable, it is recommended that starch levels should not exceed 25 to 30% of the total diet. Including a source of digestible fibre (up to 20 to 30 % inclusion of concentrate formulation) can help aid rumen function and reduce the risk of acidosis. Ground cereals should not be used at high feeding levels. Rumen buffers such as sodium bicarbonate and lime flour can help maintain rumen pH and can act as an insurance policy against acidosis.



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