BHC Newsletter Spring Edition FINAL

SPRING EDITION

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

BEEF HEALTHCHECK NEWSLETTER

FEATURE ARTICLES

BEEF HEALTHCHECK PROGRAMME UPDATE Dr Natascha Meunier | Page 2

CRYPTOSPORIDIOSIS | Maresa Sheehan | Page 4

BIOSECURITY AND PURCHASING CALVES | Dr Natascha Meunier | Page 8

NUTRITIONAL MANAGEMENT OF REPLACEMENT HEIFERS FOR OPTIMAL REPRODUCTIVE EFFICIENCY Prof. David Kenny | Page 10

NATIONAL BEEF HEALTH PROGRAMME

Animal Health Ireland, 2-5 The Archways, Carrick-on-Shannon, Co. Leitrim, N41 WN27

AHI NEWS

Beef HealthCheck programme update

Dr Natascha Meunier, Beef HealthCheck Programme Manager

W elcome to the spring editionof theBeef HealthCheck newsletter asweenter our fifth year of theprogramme. In 2020 to date, 127,250 animals have been recorded from 9,511 herds as part of the Beef HealthCheck programme, which is an average of 15,900 animals per week. Of these animals 71% were beef breeds, with 37% steers, 35% heifers, 14% young bulls, and the remainder cows and bulls. On average, 1.5% of animals had live liver fluke seen at slaughter and 7.6% had liver damage likely due to liver fluke. Abscesses were seen in 3.8% of animals and pneumonia in 1% of animals. Animals younger than 30 months of age, tended to have lower levels of live liver fluke (1.2%) compared to older animals (2.3%) as well as lower levels of fluke damage (4.3%) compared to older animals (16%). So far this year, 907 herds (9.5%) have had at least one animal with live fluke seen at slaughter. The counties with the highest levels of live fluke at slaughter were Leitrim, Longford, Monaghan, Donegal and Sligo, ranging from 9.1% to 6.7%.

9.0%

Liver fluke damage Liver abscesses Live liver fluke Pneumonia

6.0%

3.0%

0.0%

30 Dec 06 Jan 13 Jan 20 Jan 27 Jan 03 Feb 10 Feb 17 Feb

Figure 1. Conditions recorded in the Beef HealthCheck programme for 2020 weekly to date.

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

BEEF HEALTHCHECK PROGRAMME UPDATE

A liver fluke map is now available on the AHI website displaying Beef HealthCheck county-level, liver fluke information updated on a quarterly basis click here . The map currently displays results from animals that did not move from their farm of birth. These maps provide details of regional trends allowing herdowners to compare their individual Beef HealthCheck results against the county average. Farmers and private veterinary practitioners are reminded of the BHC dashboard screen available on ICBF, under AHI in the Services tab, where current and previous results of the BHC programme can be viewed for their herd. Instructions on how to access this screen can be found by clicking here .

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

FEATURE ARTICLE

Cryptosporidiosis

Maresa Sheehan, RVL, Kilkenny and member of the Parasite Control TWG

N eonatal diarrhoea caused by Cryptosportidium parvum is the second most common cause of scour in calves (rotavirus is the most common) presented to the Regional Veterinary laboratories ( All Ireland Disease Surveillance Report 2018 ). Neonatal enteritis is consistently the most frequently diagnosed cause of mortality in calves less than one month old in the Republic of Ireland. Cryptosporidium parvum is a microscopic parasite which causes scour by damaging the gut lining. It is a highly infectious, robust parasite and its eggs are resistant to many disinfectants used on farms. Cryptosporidiosis generally affects calves aged 1-4 weeks. Clinical signs include:

Lethargy/weakness Profuse watery diarrhoea with strands of mucus Dehydration

Calf submitted to Kilkenny Regional Veterinary Laboratory with diarrhoea/scour with severe dehydration, note the extremely sunken eye. Photo: Maresa Sheehan

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

CRYPTOSPORIDIOSIS

Scouring can last for a week or more and deaths can occur in severe cases. Where mixed infections (e.g. with rotavirus) occur, mortality can be high. The parasite is transmitted via the 'faecal-oral route'; infected calves pass the parasite eggs in their faeces (dung) and this is ingested by other calves. Calves may become infected from calf pens, utensils, trailers, or the clothes or boots of owners and handlers, contaminated with faeces containing the parasite. Diagnosis It is not possible to distinguish C. parvum from other causes of calf scour by the type of scour or clinical signs. • Submit faecal samples (in sterile containers) from untreated, scouring calves in the early stages of a disease outbreak to your veterinary practitioner or laboratory. • Take dead calves to a veterinary laboratory for post-mortem.

All scours can look the same, it is not possible to diagnose without laboratory testing.

Figure 2. Cryptosporidial oocysts in a faecal smear, modified Ziehl-Neelsen (Z-N) stain. Photo: Cosme Sánchez-Miguel.

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

CRYPTOSPORIDIOSIS

Management of the scouring calf Remove Remove the scouring calf and dam from the group – this helps prevent spread of infection and gives the calf a better chance of recovery. Rehydrate Give oral fluids. Healthy calves need up to 4 litres of fluid a day and scouring calves need an additional 4 litres to replace lost fluids. Give two extra feeds (2 litres each) per day of a good quality oral rehydration solution when the calf starts scouring and while scouring persists. It is safe to give these fluids by stomach tube, assuming farmers are competent and confident with the technique. If calves are being hand fed, these should be given separately from the milk feeds (for example, at lunchtime and again late in the evening). Feed milk Ensure ill calves are continuing to suckle from their dams. It might be necessary to hand feed weak calves additional milk or milk replacer as long as they want to drink. Do not feed diluted milk to calves. Continued suckling or feeding with milk or good quality milk replacer does not cause, worsen or prolong scour. Milk or milk replacer should not be stomach-tubed, as this can lead to the build-up of acids in the rumen and damage the ruminal wall. Halofuginone lactate Halofuginone lactate (a prescription-only medicine) can be used preventively in new-born calves at risk of C. parvum infection and calves in-contact with C. parvum -positive calves. Scouring calves diagnosed with C. parvum may also be treated with halofuginone lactate. While the therapeutic impact of this drug on scouring calves is unclear, it may reduce the severity of disease if administered within 24 hours of the onset of scour. In all cases, it is given to the calf by mouth after a feed, once a day for seven consecutive days. Disease control/prevention measures • Ensure all calves receive sufficient colostrum within 2 hours of birth. Suckler calves should be monitored to ensure they are feeding from their dams, and hand fed colostrum if needed.

• Provide adequate bedding and replace regularly. • Ensure strict hygiene with feeding equipment. • Raise feeding and water troughs off the floor by 0.75m. • Wash hands, change clothes and footwear after handling sick calves.

• Thoroughly clean and disinfect calving and calf pens with a disinfectant effective against C. parvum and ideally leave free of animals for 3-4 months before the next calving season. Oocysts are susceptible to dessication (drying out).

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

CRYPTOSPORIDIOSIS

Spread to humans C. parvum can infect humans. Farmers should wash their hands, change their clothes and footwear after handling sick calves. Children and immunocompromised adults should not care for sick calves. Farmers should comply with all regulations on slurry and run-off water from animal buildings to ensure a clean water supply for their families and the general public.

Key points • Cryptosporidium parvum is a microscopic parasite that causes scour in young calves. • Remove, rehydrate and feed milk to manage the scouring calf. • Halofuginone lactate may be used on farms where C. parvum has been diagnosed. • Strict hygiene is crucial to prevent and control C. parvum.

See the AHI leaflet 'Cryptosporidiosis in neonatal calves' for more information. click here

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

FEATURE ARTICLE

Biosecurity and purchasing calves

Dr Natascha Meunier, Beef HealthCheck Programme Manager

T here are two disease-related aspects to consider when buying calves: protecting your herd from new diseases and ensuring the calves themselves remain healthy. Firstly, purchasing animals is the most common way to introduce disease onto a farm. Ideally, keeping a closed herd i.e. not buying in animals, minimises this risk of bringing disease onto the farm but this is not always possible. Animals can appear to be healthy but still carry disease, so a good biosecurity plan should help reduce the risk of bringing diseases onto the farm, especially if the herd is free of specific diseases. Secondly, purchased animals are at risk of becoming infected following introduction from the animals already in the herd or they may not be able to fend off more common conditions due to the added stressors of transport and a new environment. Purchase animals from low risk herds If possible, buy animals from a herd where information is available on their health status. Herds with a lower disease risk and good calf management and vaccination regimes will lower the risk of purchasing infected animals. Buy animals from as few herds as possible to minimise the disease risk. Selecting low risk animals - healthy calves Moving animals to a new farm environment and mixing with new animals can be stressful, leading to weakening of their immune system and the animals are more likely to become clinically ill. Before transporting, ensure the calves are healthy – bright, alert and responsive. Source calves from farms that follow good calf management practices, particularly colostrum management, to minimise the risk of scour and pneumonia after being brought onto farm. Calves receive antibodies from colostrum that are essential to protect against infections and if colostrum intake is not sufficient, they are more likely to suffer from disease, especially after a period of stress. Best practice for colostrum management includes feeding a good quality and quantity of colostrum to calves within 2 hours of birth. Suckler calves should be monitored to ensure they are feeding from their dams, and hand fed colostrum if the cow is not allowing the calf to suckle, had a difficult birth, or if the calf is too weak to suckle. Scour and pneumonia are common diseases in young calves and can have a number of causes including bacteria, viruses and parasites. Animals that show any sign of disease should be separated from the group into a sick pen. Good hygiene practices such as washing hands and boots after handling sick animals, as well as washing equipment including feed buckets will help prevent the spread of disease to healthy animals. Control and prevention of diseases will depend on what the particular problem is on farm but vaccines are available against specific bacteria

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

BIOSECURITY AND PURCHASING CALVES

and viruses. Consult your veterinary practitioner as to what steps could help prevent issues from arising and whether vaccination is necessary. Preventing these diseases with good hygiene and vaccination have the added benefit of reducing labour in caring for sick calves and reducing antibiotic usage. Implement a quarantine period A quarantine period should be implemented for animals being introduced into a herd. These animals should be housed separately without nose-to-nose contact with the main herd and ideally, should not share the same airspace. It is advised to keep animals quarantined for at least four weeks during which time they can be monitored for any clinical signs, vaccinated, dosed and tested as needed.

What to do when new calves are brought on farm • Keep newly introduced animals away from other stock on farm. • Monitor that they are healthy and separate out any ill animals. • Keep calves in dry, draught free areas, with good ventilation. • Make clean water freely available. • Ensure adequate feeding so that calves are not hungry. High disease risk • Purchasing calves from a herd with an unknown disease history. • Purchasing ill, weak calves or young calves with an unknown colostrum intake. High stress risk • Calves kept in cold, wet draughty bedding areas. • Mixing of animals from multiple farms. Before buying calves, discuss with your veterinary practitioner the specific disease risks for your farm, especially if you do not normally purchase animals. The existing herd or the newly purchased animals may benefit from vaccination or disease testing before mixing the new animals with main herd.

For more information, see the AHI leaflet on biosecurity when purchasing stock click here .

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

FEATURE ARTICLE Nutritional management of replacement heifers for optimal reproductive efficiency in the suckler herd

Prof. David Kenny, Principal Research Scientist, Teagasc Animal and Grassland Research and Innovation Centre, Grange

R eproductive efficiency is a major determinant of both the economic and environmental sustainability of suckler beef cow enterprises. In Ireland, 75% of replacement beef heifers are sourced from the beef herd, either homebred (60%) or purchased (40%). Teagasc data clearly show that rearing heifers to calve at 36 compared with 24 months of age results in a reduction in net margin per hectare on suckler beef farms of 20-30%. This is mainly a consequence of the feed costs associated with maintaining a cohort of ‘unproductive’ animals within the herd for an additional 12 months. Furthermore, international studies indicate that beef heifers that calve for the first time at 24 months of age have greater longevity within the herd than their later calving contemporaries. First calving cows typically undergo a longer delay in resuming normal heat cycles after calving, compared with older herdmates. For this reason, the earlier in the breeding season that a heifer calves, the greater the probability that she will become pregnant within the subsequent breeding season. As a result, age-at-first calving has been identified as one of the five key performance indicators in seasonal, spring- calving suckler calf-to-weaning systems where replacement heifers are reared within the herd, with the economic impact estimated at €50 per month for every suckler cow in the herd (Irish Cattle Breeding Federation; ICBF). In addition to its obvious economic importance, work by Teagasc indicates that older age at first calving increases the lifetime emissions burden of the cow and, correspondingly, the emissions per kg of beef produced through digestion of feed, feed energy and manure management emissions. It is estimated that the impact

Reproductive efficiency is a major determinant of both the economicand environmental sustainability of suckler beef cow enterprises.

Teagasc data clearly show that rearing heifers to calve at 36 compared with 24 months of age results in a reduction in net margin per hectare on suckler beef farms of 20-30%.

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

NUTRITIONAL MANAGEMENT OF REPLACEMENT HEIFERS

of age at first calving is to increase GHG emissions by 0.01% /kg beef carcass, for each day that first calving is extended beyond 24 months of age (baseline replacement rate of 20% per annum assumed). However, despite its undisputed importance, national herd statistics indicate that only 23% of beef heifers calve for the first time between 22 and 26 months of age, with the average age of first calving at 30 months of age (ICBF). Sexual maturation culminating in puberty onset is regulated by a complex network of biochemical processes and involves interaction among many key metabolic, neuroendocrine and reproductive tissues. Early onset of puberty (by 13-14 months of age) is essential to achieving first calving at 24 months of age. While factors, such as biostimulation (prior exposure to a bull) can apparently advance the onset of puberty in well grown beef heifers, the primary effectors of the timing of sexual maturation in cattle are undoubtedly nutritional management and genetics. In particular, there is now overwhelming evidence to support the importance of early life nutrition (prior to 8 months of age) in regulating the timing of puberty, with pre-weaning live weight gain having a much larger impact than post-weaning gain. Indeed, recent work conducted at Teagasc Grange, and funded by the Department of Agriculture, Food and the Marine, clearly shows that offering heifer calves a high plane of nutrition between 4 to 8 months of age significantly advanced the age at puberty onset (by approximately 2 months). This led to a twofold greater number of pubertal heifers, eligible for breeding at the start of the breeding season (see Figure 3).

Indoor winter period Turnout Start breeding season

0 10 20 30 40 50 60 70 80 90 100

Figure 3. Effect of plane of nutrition (High v Moderate) offered between 4 and 8 months of age on the cumulative proportion (%) of pubertal Angus heifers from housing up to two months post turnout (Teagasc Grange).

300

350

400

450

500

Average age (days)

High

Moderate

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

NUTRITIONAL MANAGEMENT OF REPLACEMENT HEIFERS

These findings were in contrast to the results of another related study at Grange, where we only observed a modest reduction (2 weeks) in the age at puberty onset in Angus and Limousin sired heifers (bred from either beef or dairy cows), offered a high compared to a moderate plane of nutrition from 8 to approximately 13 months of age (while indoors over winter). The caveat of the latter study, however, is that these heifers were already relatively well grown at 8 months of age and had they been less well developed at the start of the study, we may have observed a greater impact of preferential feeding. While in both of the aforementioned studies, normal pregnancy rates were achieved during the subsequent breeding season, heifers that reach puberty in advance of the breeding season have a higher submission rate and thus a greater chance of becoming pregnant within the first six weeks of breeding – a key target for suckler herds. Currently, our research is focussed on an in-depth investigation on both the direct and interactive effects of improved nutrition on the underlying regulatory genes and biochemical processes involved in sexual development in the young heifer. Optimal nutritional regimens can then be formulated to consistently and cost-effectively ensure that a high proportion of replacement heifers reach puberty before the start of the breeding season, a central tenet of economically and environmentally sustainable, seasonal calving, grass-based production systems.

Furthermore, international studies indicate that beef heifers that calve for the first time at 24 months of age have greater longevity within the herd than their later calving contemporaries

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BEEF HEALTHCHECK NEWSLETTER | Spring Edition

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