This is the first in a series of three articles that examine the opportunities for veterinary practitioners and livestock advisers to engage sheep farmers in proactive health and production planning. It focuses on the use of on-farm records to identify specific flock health, welfare and production issues and for setting farm-specific targets and action plans. Subsequent articles in the series will look at flock nutrition, and ways in which financial and performance indicators can be used to demonstrate the economic and future benefit of flock health planning.
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Clare Phythian worked in practice for several years before undertaking a PhD in sheep health and welfare on farms across England and Wales. She holds the European diploma in small ruminant health management.
Kate Phillips has been a principal livestock consultant with ADAS UK for nearly 30 years and specialises in sheep husbandry, nutrition, health and welfare.
Nerys Wright is an assistant regional manager for EBLEX. She has a particular interest in sheep production covering animal health, nutrition and husbandry.
Mair Morgan is a livestock consultant working for ADAS UK. Specialist areas include sheep and cattle husbandry and health and grassland production.
Flock health plans and active health planning
Sheep farmers need to balance high standards of flock health and welfare with producing safe, high quality food and maintaining a profitable and sustainable business. As part of this, flock health planning has been used as a tool for focusing inputs in flock health and management in order to attain optimal physical and financial performance. An earlier In Practice article described some of the key areas that veterinary flock health plans should cover, including disease control strategies, a whole cycle of production approach and incorporating a means of monitoring and assessing flock health and production outcomes (Lovatt 2004). As well as being part of national animal welfare regulations, such as the Defra 2004 code of recommendations for the welfare of sheep (Defra 2004), flock health plans are also a stipulation for membership of certain farm-assurance schemes. The presence of a health plan is often used as a measure to assess producer compliance with farm-assurance schemes. However, a ‘tick-the-box’ approach does not take account of whether the health plan is being actively applied, and/or if the actions listed are appropriate and have been tailored to the individual farm.
Any flock health plan needs to be flexible and robust enough to allow for ongoing review and development as farm priorities and progress is made, as well as being dynamic to advances in scientific knowledge and veterinary advice. Therefore, there needs to be a distinction between so-called ‘blueprint’, one-off flock health plans that may be used as evidence of compliance for assurance or statutory regulations, and those that are the result of proactive health and production planning processes (Vaarst and others 2011).
Blueprint flock health plans often involve listing diseases and appropriate action plans and can be seen as reactionary, offering only a short-term response to deal with known health issues; they are not flexible to responding to changes in farm issues and disease risks in order to meet industry demands for long-term efficient and productive farming systems.
The objective of proactive veterinary flock health planning is to offer a tailored, targeted and preventive approach to facilitating improved animal health and increased physical and financial productivity. The plan can be seen to be ‘active’ in the sense that it is specific to the farm, is flexible to changes in farm priorities or the emergence of new disease issues, and allows review or improvements to be made in response to target progress. This method is based on the assessment of management and resource inputs and physical and financial outcomes, involving detailed and critical analysis of farm records. It may require further diagnostic investigations and assessments, and possibly additional input from external advisers, such as grassland management advisers, nutritionists and production/business consultants. Therefore, the development and delivery of ‘active’ health plans allows practitioners to gain a good knowledge and understanding of the management system, the level of production and financial aims, time and resources available, as well as potential barriers to improvements or other priorities in the farming enterprise. Clearly, such an approach requires greater veterinary and producer input and will involve multiple conversations with the producer, repeat farm visits, and in-depth analysis of farm records and test results.
Using records as a tool for benchmarking flock performance
A good understanding of the producer's personal objectives, farm production and disease history, together with clinical knowledge of flock health status, plays a key part in health and production planning. In addition, a variety of records need to be maintained on sheep farms to identify targets and select areas where veterinary involvement and implementation of proactive health planning would be of value to the health, welfare and productivity of both the sheep and the producer. Records are, therefore, an essential aspect of benchmarking and using them to measure and monitor farm targets should form the basis of all flock health plans. However, an ADAS survey (2007) of 403 sheep farmers found that only 44 per cent of farmers maintained performance records, and not always as part of a farm health plan, and only 23 per cent of farms performed benchmarking. Therefore, there is clearly more potential for practitioners to support sheep farmers in maintaining records and for greater delivery of proactive veterinary services to optimise flock health, welfare and production.
Close scrutiny of farm records and comparison of measurable outcomes with appropriate peer and industry benchmarks or previously agreed targets can inform management decisions with the ultimate aim of improving flock health, welfare and production year on year. A key part of any plan is reducing avoidable losses from clinical problems. The benefit of records is that they can provide evidence of subclinical or suboptimal performance that may not be so visible from a clinical assessment and hence can be used to prevent diseases or other issues before they have a significant impact on the flock. Following an initial review and analysis of records and comparison to benchmarks, the priority areas and targets should be identified and agreed by the farmer and adviser. Initially, aim to address two achievable targets in the short term. As progress is made, other targets can be set. Allowing the producer to identify their own flock targets is considered a key step for the successful implementation of animal health plans (Vaarst and others 2011) and should also mean that the objectives set are realistic and achievable. It is useful to briefly document the targets and agreed actions in order to record the current situation and also for future reference when monitoring progress later. A variety of computer-based planning tools are available to help veterinary surgeons incorporate animal health, physical and financial indicators of flock performance into health planning, for example the animal health and production planning programme of the Scottish Agricultural College (www.sahps.co.uk) and the Scottish Government animal welfare monitoring and benchmarking scheme (www.animalhealthscotland.gov.uk).
This approach provides ongoing monitoring and continued progress on the targets set. Focused health planning provides a good basis for further veterinary involvement and consultancy on a wide range of topics for the keen sheep practitioner, and can be an excellent way to develop further clinical skills and establish good working relationships with several sheep producers. The main benefits of measuring and monitoring impact for the producer often include improved performance and profitability.
Record-keeping on sheep farms varies hugely, from the use of counting bags of dead lambs, a back-of-the pocket notebook, to more in-depth paper-based records and the use of electronic identification (EID) systems for recording lambing losses (Fig 1). Whatever the recording system, the key measures for farmers to record at lambing include: date, number of lambs born alive/dead, whether it is a single/twin/triplet lamb, and any known or presumed reasons for losses (Lovatt 2006). Evidently, the best records are those that are simple and easy to understand, kept in a weather-proof format and can be easily gathered on farm. As with all data, the quality and accuracy of information recorded is open to error and delays in operator recording but, used in conjunction with the history of the farm, clinical assessments and dialogue with the producer, they are valuable for identifying specific issues and setting targets that are relevant to the farm. As well as maintaining flock records, there is an increasing need for records of individual animal identification as part of movement and food safety regulations. Such information not only provides greater traceability of animals within the food chain but also helps to inform breeding and management strategies, for example recording of lamb growth rate to select rams and ewes with resistance and/or resilience to gastrointestinal parasites, or helping to select for particular maternal traits in ewe replacements.
There are many opportunities and benefits to recording animal details such as weight, condition score and health status. This information can be used to help select high performing animals for replacements, but can also be used to identify underperforming animals and other health issues. Since paper records can easily get lost or damaged, some shepherds have voluntarily recorded their whole flock using EID methods, as this offers a useful and practical means of collecting and analysing data on the performance of individual and groups of sheep.
Given that the availability of records is flock-specific and certain measures rely on scanning data, a list of ‘essential’, ‘desirable’ and ‘nice-to-have’ records to collect during flock visits is suggested (Table 1). Records are prioritised in this way so that if, for example, the flock does not currently undertake pregnancy scanning the practitioner can still make use of essential figures, such as the total number of ewes put to the tup and the number of lambs sold or still on the farm, to do a basic calculation of rearing percentage and compare with industry targets. This can also indicate whether ram power (ratio of rams to ewes) is appropriate.
The Farm Animal Welfare Council recommended that, the targets for reducing the prevalence of lameness in the UK flock should be from 10 per cent to 5 per cent by 2016 and to two per cent by 2021 (FAWC 2011). On this basis, it could be suggested that a prevalence of four or more cases of lameness per 100 ewes during any routine stock inspection or flock health visit warrants further veterinary investigation to check that the diagnosis is correct, and that flock lameness treatment, control and prevention plans are appropriate and promptly applied. For other conditions, for example respiratory disease, hypomagnesaemia, hypocalcaemia, pregnancy toxaemia, mastitis, vaginal prolapse and septic arthritis, it may be more appropriate to record and regularly review the levels of these conditions to guide further investigations and management decisions, rather than give general threshold levels for intervention.
Flock health and production indicators
Useful health and production measures that can be identified in farm records are discussed below.
Mortality in adult sheep
In the UK, there is a legal requirement to maintain up-to-date mortality records, so this is a source of information all farmers should have readily available. Annual losses of 2 to 3 per cent of ewes and rams are generally considered to be ‘acceptable’, but higher levels may suggest an underlying health and welfare problem and further investigation would be worthwhile (Fig 2). High levels of ram deaths or rams that fail to thrive and lose condition quickly may identify that rams need to be sourced from farms of known health status and nutritional management, and that appropriate quarantine protocols are followed. High numbers of ewe death could suggest significant health issues, suboptimal nutrition, or that ewes are being retained on the farm for too long.
When examining lamb losses (Fig 3) there are five key periods in the sheep production cycle to assess:
At lambing – to identify losses from scanning to lambing.
At lambing – to identify deaths within the first 24 hours post lambing.
The first week of life or to turnout.
From lambing to weaning.
From weaning to sale or retention.
Records collected at these critical points in the production calendar can be used to calculate the following physical outcomes:
Scanning percentage=(total number of lambs expected from scanning/ total number of ewes put to the tup) x 100.
Barren rate=(total number of barren ewes/ total number of ewes put to the tup) x 100.
Lambing percentage=(total number of lambs born alive/total number of lambs expected from scanning data) x 100.
The lambing percentage reflects lamb losses from scanning to lambing, and this calculation is also known as ‘actual lambing percentage’.
Turnout percentage=(total number of lambs turned out/ total number of lambs expected from scanning) x 100.
Rearing percentage=(total number of lambs reared/ total number of ewes put to the tup) x 100.
Lamb losses=(total number of lambs sold or retained for breeding/ total number of lambs expected from scanning) x 100.
Previous surveys of UK flocks identified that neonatal lamb mortality was at a mean of 10 per cent incidence (Binns and others 2002). More recently, a survey by Hybu Cig Cymru (HCC – Meat Promotion Wales) of 70 farmers who recorded lamb losses throughout the 2010/2011 breeding season identified that just under half (49 per cent) of all lamb losses occurred within 48 hours of lambing, 30 per cent were lost from scanning to lambing, 11 per cent were lost two to four days after lambing, and a further 10 per cent were lost two weeks post-lambing and onwards (HCC 2011). Across the hill, upland and lowland flocks in Wales contributing to the survey, 14 to 16 per cent of lamb losses were due to the ewe dying before or during lambing, with many of the deaths being attributed to vaginal prolapse. Losses from ewe deaths during the scanning to lambing period need to be accounted for, but may not always be readily identified from producer records. A further 26 per cent of the total losses were reported as abortion or stillbirths, and a further nine per cent of lambs were lost to disease (HCC 2011). Clearly, many of these issues could be reduced and prevented by improved ewe nutrition, proactive veterinary health planning as well as improvements in the lambing environment (Fig 4).
As a rule of thumb in the UK, lamb losses from scanning to sale are around 15 to 20 per cent (EBLEX 2012). Producers should be aiming for less than 15 per cent and preferably closer to 10 per cent or less. Taking into account that most losses occur at lambing time, these targets could be broken down further into <5 per cent losses from scanning to lambing, <5 per cent during lambing and first week of life, <2 per cent from first week to weaning, and <2 per cent from weaning to sale or retention.
As well as comparing the overall scanning percentage with previous years, it is useful to examine the breakdown of scanning figures by ewes and ewe lambs, and to determine the proportion of barren, single and multiple-bearing ewes. Barren rates over 2 to 3 per cent are a useful indicator of flock performance where levels exceed two per cent it is useful to investigate whether infectious causes of abortion, particularly toxoplasmosis, are involved. This will help inform the short-term management of barren ewes as well as longer-term health and production planning, such as reviewing flock vaccination protocols and the health status and source of bought-in animals. Poor scanning results and low body condition of barren ewes may suggest suboptimal nutrition and specific health issues. Ideally, assessment of body condition should be performed pre-tupping, to assess the adequacy of nutrition (Russel 1984). Dry summers leading to a lack of good quality grazing for flushing can be associated with poor scanning results, such as high numbers of single-bearing ewes and/or high numbers of empty ewes. High numbers of barren ewes may also suggest that ram fertility needs further investigation (Boundy 1992). A lower scanning percentage is desirable and expected in ewe lambs (no more than 120 per cent), and these animals should ideally only rear one lamb. In cases of poor scanning in ewe lambs, as well as ruling out infectious abortion agents, trace element imbalances and ram fertility issues, it is important to find out whether ewe lambs were tupped at the appropriate weight and body condition (recommended to be 60 to 75 per cent of the mature weight at the time of tupping).
The overall scanning results and number of ewes mated can be used to calculate the total number of lambs expected (scanning per cent x number of ewes=total number of lambs expected). This can be compared with the ‘true’ lambing percentage; the number of lambs reared (sold or retained) expressed as a percentage of ewes put to the tup. In a lowland situation, the target rearing percentage should be over 150 per cent and preferably closer to 170 per cent. That said, EBLEX 2012 figures for 42 performance-recorded flocks suggested that the ‘average’ lowland flock achieved a 159 per cent rearing percentage and the top third of flocks (14 farms) achieved a rearing percentage of 162 per cent. Evidently, it is important to examine the age of ewes at breeding; if a large number of ewe lambs are put to the tup, then the overall lambing percentage will be reduced, as prolificacy generally improves with age.
Lamb sales information is generally readily available and records can be broken down into the proportion sold finished, sold or retained as stores, sold or retained as breeding replacements and the sales profile. Grading information based on the EUROP system from dead-weight sales can be used to indicate whether lamb selection and finishing is optimal and if the lambs are hitting market specifications and achieving optimal performance (Fig 5). For example, a high proportion of lambs finishing at fat class 4 or 5 indicate that lambs are not being selected early enough and should have been sold sooner.
The lamb sales profile might show high numbers of stores or low numbers of lambs finishing irregularly throughout the season. This might indicate issues with finishing and could involve further investigations of parasite control, trace element status, grassland management and lamb nutrition.
Where lamb losses are not recorded, lamb sales information and fallen stock receipts can be used as a crude means of identifying the number and timing of lamb losses. Again these receipts might suggest particular issues during the neonatal period, at turnout or after weaning.
All abattoirs provide producers with feedback on the condition of individual carcases, including weight, conformation, fat class or complete rejection of the carcase. Some abattoirs provide partial rejection information. Abattoir surveillance undertaken for public health purposes provides abundant information pertinent to flock health and production. The information relayed back to the producer varies between abattoirs but, in general, condemnation information is usually provided if a considerable number of animals are affected. Clearly, it would be preferable to know when a low number of animals show signs of disease, for example signs of liver damage may be an early indicator of fluke problems in the whole flock, and early and accurate detection at the abattoir could inform specific parasite control plans for the farm. We would recommend that producers ask for this information every time a batch of lambs or cull ewes is sold direct to the abattoir, as this information is not always routinely provided.
Culling and replacement rates
Ideally, records on the dates, numbers and reasons for culling should be maintained on all farms. Where detailed records are not available, it can be useful to examine market and abattoir receipts to identify numbers of cull animals. Ewe replacement rates around 20 per cent are generally expected, that is, a 400 ewe flock would need to retain or buy 80 ewe lambs or yearlings. Replacement rates of over 20 per cent could indicate issues with high mortality and should instigate further investigation into the timing of losses as well as any disease or nutritional issues. At the other extreme, low replacement and culling rates may indicate good flock health, welfare and production, or may corroborate advice on a stricter culling policy for particular health issues, such as the need for higher culling rates to remove repeatedly lame sheep from the flock or to reduce problems with old ewes (eg, poor body condition and lack of milk) at lambing time.
To encourage farmers to keep records, practitioners could provide simple recording sheets for farmers to record the information as ewes, rams or lambs are sold or animals die. In addition to farm visits, regular telephone contact with the client is often needed for prompt, regular recording, and giving quarterly review dates will help to instil some discipline into recording. Many farmers record all ‘sheep events’ (births, deaths, purchases and sales) in their diary so this can be interrogated to find any missing information. Asking farmers to tally the number of culls and reasons when cull ewes are marked or tagged, and using wet or dry lamb deaths as a measure of age at death, can provide other means of getting some health and disease data.
Medicines and health records
There are legal requirements for farmers to keep records of medicines use. These records can be used to identify high usage of a particular drug(s), or perhaps indicate particular individual or flock diseases. Individual records of specific diseases such as lameness, mastitis and metabolic diseases, and faecal egg count records, clearly provide valuable data.
Performance records are generally used by pedigree sheep producers to inform selection of breeding stock with particular production or genetic traits. General outcomes maintained by some producers include:
Number of lambs reared per ewe (rearing percentage)
Finishing weights and average lamb finishing weight
Finished lamb price
Flocks that take part in the Signet recording scheme may be required to maintain accurate records on lamb birthweight, weight at eight-weeks, and muscle and fat depth ultrasound assessments at 21 weeks. This data is used to determine Estimated Breeding Values (EBVs), which are used as an indicator of breeding potential for traits such as prolificacy, lamb growth rate, and lean carcase characteristics. Additional ‘desirable’ physical indicators that may be identified from EBV-recording, pedigree or well-recorded commercial flocks include:
Average lamb birthweight
Total kg of lamb produced
Weight of lamb produced per ewe
These measures can be compared with the farm objectives and industry benchmarks to identify whether lamb rearing and finishing is optimal and meeting market specifications.
Most farms will keep copies of invoices and receipts for accountancy and tax purposes, and this information can be used to examine the costs of the sheep enterprise as part of a gross margin analysis. This level of flock evaluation can take some time to examine and is an area where the support of livestock consultants can be invaluable. Further use of financial records will be covered in more detail in another article in this series.
Key aspects of benchmarking and setting targets
Establish baseline performance of the flock and identify whether sheep are the major enterprise on the farm.
Select two key targets to focus on initially: focus on the concerns of the producer together with any immediately apparent and serious health and welfare concerns; other areas can be added in as the health and production priorities change.
Agree on achievable objectives for the next production year.
Evaluate current recording systems and implement improvements or additions where feasible.
Ensure the producer is aware that the health plan will need to evolve or be amended following review.
Identify any barriers preventing implementation of certain actions, and the costs and impacts of changes to management practices for health interventions (such as time, labour, money and other resources).
Continue to regularly measure and monitor target outcomes and assess sheep records, as well as farmer perceptions and experience.
Expect that improvements to financial indicators might take some time – use a range of measures.
Maintain regular contact with the producer and review and update plans regularly.
Applying benchmarking and setting targets
Where more detailed health and production data is identified, it is useful to compare these figures against recommended benchmarks from farms of a similar type. Benchmarks for UK sheep flocks include those identified by the Farm Business Survey, English Beef and Lamb Executive (EBLEX), Hybu Cig Cymru (HCC) in Wales, or Quality Meat Scotland (QMS), or the Livestock and Meat Commission (LMC) in Northern Ireland.
Farm records can be used as part of a systematic and standard approach to setting farm-specific targets, health monitoring and assessing the impact of health or management actions. While records are historical, they do provide a useful benchmark to compare current performance with previous year's results, and can act to highlight the presence or risk of a particular health, welfare or production issue. Farmers who, at first glance, do not evidently maintain in-depth records or go beyond the legal compliance for record keeping will have breeding and production information and records in the form of invoices and lamb sale receipts. Along with clinical knowledge and evaluation of farm resources such as housing, nutrition, and grassland management, this information can identify opportunities where veterinary surgeons could work more closely with producers to develop a tailored action plan that is of benefit to flock performance. More importantly, using records means that targets can be based on the farmer's own objectives and priorities for the flock, which is important if the plan is to be an effective working document. The selection of flock-specific targets by the farmer is suggested to be a key driver for the successful on-farm implementation of animal health and production plans (Vaarst and others 2011).
As part of the active planning process, it is vital for the veterinary surgeon and producer to set agreed farm-specific targets that can be measured both physically and financially. Some useful measures are shown in Table 2. Any health or management actions arising from the plan need to be regularly reviewed with the practitioner and to regularly measure the progress against targets and benchmarks. All parties involved should be aware that any plan is not ‘set in stone’ and that it is expected that amendments and adjustments will be made to ensure that improvements are feasible and effective for the farm. Therefore, continual follow-up of the plan is a fundamental step in proactive flock health planning. Evidently, the timing of reviews and repeat visits or contact will depend on the measures and issues in question. As a guideline, at least quarterly health visits at key points (for example at scanning time, pre-lambing, lambing, turnout, pre-weaning, cull ewe selection, and pre-tupping) are needed for health-based assessments, such as body condition scoring, and disease control review and updates. Reviews and amendments of animal health and welfare action points need to be made regularly so that real progress can be made. The involvement of other specialists, such as grassland management advisers and agronomists, can be integrated at other stages of the production cycle as part of a whole-flock and team approach to flock health, welfare and production planning. For assessment of physical and financial performance, these areas should be monitored annually to give sufficient time to assess impacts of specific inputs, such as flock vaccination protocols and veterinary advice, on subsequent performance.
Opportunities using electronic identification records
Electronic identification (EID) can facilitate acquisition of accurate records for measuring and monitoring flock performance. Applications include:
Evaluating the performance of growing lambs by recording weight and calculating daily live weight gain (DLWG) (Fig 6).
Monitoring performance of the progeny of different rams.
Selecting specific maternal and neonatal lamb traits (eg, lambing ease, lamb vigour scores).
Assessing the effect of various treatments (eg, effect of trace element supplementation on DLWG).
Use of DLWG information as part of a targeted selective treatment (TST) approach to parasite control or comparing performance of animals on different diets.
EID can also be effectively used to record treatments and decisions made on individual animals, such as assisted births, lamb vigour, mothering ability, and any medicines or treatments given to individual animals – information that can be used to help select the best replacements.
Abattoirs are also increasingly providing feedback on individually identified animals. This information can help farmers to improve lamb selection but also help identify health issues. Clearly, there are benefits from using EID beyond compliance with legal regulations, for measuring and analysing flock data and ultimately informing management and financial policy changes in both pedigree and commercial flocks.
Recording and benchmarking is a valuable means of assessing the impact of health plans and veterinary advice. Encouraging sheep producers to maintain accurate records aids planning and supports key management decisions. However, at the start of a flock health planning programme, even in the absence of obvious records, there are potential sources of data that may identify areas where sheep veterinary surgeons, livestock advisers, and nutritionists can work together to have significant, beneficial effects on flock health, welfare and production.
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