Pre-slaughter Phase

4 Pre-slaughter Phase


4.1 Farm-to-Abattoir Phase


PAUL WARRISS


Introduction

Practically all the animals that we produce must eventually be slaughtered, even if their primary value to man has not been as a source of meat. In the UK we slaughter every year about 900 million poultry, 10 million pigs, 15 million sheep and 2 million cattle. Getting these from farm to abattoir forms the first link in the chain of meat production and one that is both important and, to some degree, contentious. It is important because how it is done can influence carcass and lean meat quality, and contentious because the processes of handling and transport provide many opportunities for the animal’s welfare to be compromised. In fact, quality and welfare are closely linked. Improvements in one are often associated with improvements in the other.


Animals can spend a long time getting from the farm to the slaughter plant. Additionally, they may spend time held in lairage, which can prolong this potentially stressful period, and many are sold, not directly, but indirectly through live auction markets. About 60% of cattle and 70% of sheep in the UK pass through markets. This practice increases the overall number of journeys. The period is stressful because it involves removal of animals from their home environment and holding in unfamiliar surroundings, food and water deprivation, exposure to noise, strange smells, vibration and changes of velocity, extremes of temperature, the breakdown of social groupings, close confinement and sometimes overcrowding. The longer that animals are exposed to these stressors the greater the chance that their welfare is compromised and that carcass and meat quality are reduced.


Journey times are likely to have increased because of changes in the structure of the slaughtering industry. The number of red meat slaughter plants in 2000 was less than one-third of those operating 20 years previously, and these plants were generally bigger. Overall, nearly 50% of red meat animals are now killed in plants with throughputs greater than 100,000 animals per year, and the average throughput of these plants is nearly 200,000 per year. There are therefore fewer local abattoirs and the remaining larger plants operate at higher line speeds. Faster processing requires moving animals more quickly and this is likely to be more stressful.


Effects on welfare and quality

A number of quality problems attributable to pre-slaughter handling can be recognized and these generally also reflect poor welfare. Animals may die, they may suffer trauma such as bruises or broken bones, long periods without food may reduce carcass yield, deprivation of water may cause dehydration, and stress may produce poor quality of the lean meat. In particular, short-term (acute) stress may stimulate glycolysis immediately post-mortem and produce PSE (pale, soft, exudative) meat, and long-term (chronic) stress may deplete muscle glycogen levels and produce DFD (dark, firm, dry) meat. The transport of animals can spread disease, which has implications for both welfare and quality, and may compromise traceability if systems for animal identification are less than perfect. Effective traceability, so that the exact origin and provenance of each piece of meat sold at retail are known, is central to the quality control of hygiene and safety.


Legislative control of transport and animal handling procedures

In the UK the handling of animals during the period from farm to slaughter is currently controlled by four main pieces of legislation. Transport is governed by The Welfare of Animals (Transport) Order 1997, handling in markets by The Welfare of Animals at Markets Order 1990, and handling at the abattoir by The Welfare of Animals (Slaughter or Killing) Regulations 1995 and The Fresh Meat (Hygiene and Inspection) Regulations 1995. UK legislation reflects EU Directives, so in general terms European legislation is harmonized. The general provisions of The Welfare of Animals (Transport) Order 1997 make it an offence to cause injury or unnecessary suffering or to transport unfit animals. Transporters must be authorized by the appropriate Government Minister, animal handlers must be competent (as demonstrated by training or experience) and all journeys must have appropriate documentation. The Order prescribes amongst other things, maximum journey times, space requirements and feeding and watering intervals. Although legislation is always subject to change the general principles embodied in it are unlikely to. In general, if there is change, it tends to be in the direction of stronger protection for the welfare of animals. For example, there is currently much pressure to reduce maximum permitted journey times.


Fitness to travel

Animals that are ill, infirm or fatigued (unless only slightly affected and where the intended journey is unlikely to cause them unnecessary suffering) are unfit to be transported. Transport is prohibited in pregnant animals (likely to give birth, or within 48 h of birth) or new-born animals in which the navel has not completely healed. Animals must be able to be loaded without using force and be able to bear weight on all four legs. Examples of unfit animals include animals suffering pain (which is likely to be made worse by transport), animals with fractures or severe wounds, animals with prolapses and lame animals.


The Welfare of Animals (Transport) Order 1997 (Section 6) allows an unfit animal to be transported to the nearest available place of slaughter if the animal is not likely to be subject to unnecessary suffering by reason of its unfitness. The Fresh Meat (Hygiene and Inspection) Regulations 1995 (Part V, 17(2)(a)–(b)) require that the animal be accompanied by a written declaration by the animal’s owner, or person in charge of it, which is handed to the Inspector or OVS (Official Veterinary Surgeon) on arrival at the slaughterhouse, and which contains the information prescribed in Schedule 18 of the Regulations. This is often referred to as the ‘Schedule 18 declaration’ and includes declarations regarding the animal’s identity, medicinal treatment it has received and signs of disease or injury exhibited. The decision of whether an animal is fit to travel is that of the owner. The Declaration does not have to be signed by a veterinarian. If a person certifies that an animal is fit to travel, but the Inspector or OVS at the abattoir thinks it was not, the person is open to prosecution because the animal is likely to have been caused unnecessary suffering.


Stocking densities in transit

There are commercial pressures to increase stocking densities. The more animals that can be carried on a transport vehicle, the less the average cost of transport per animal. The legislation prescribes appropriate space allowances. In general, animals should have enough space to lie down. For example, the loading density for pigs weighing around 100 kg should not exceed 235 kg/m2, equivalent to 0.425 m2/100 kg live weight. This is about the space needed by a pig to lie down in sternal recumbency. The legislation points out that in hot weather the space allowance may need to be increased by up to 20%. The reason for this is that pigs are very sensitive to overheating in hot weather and at high stocking densities they may be unable to cool themselves effectively. In the worst case they will die. Transporting cattle at high stocking densities has also been shown to increase levels of bruising.


Mortality in transit

Death of an animal is the ultimate compromise of its welfare and results in total loss of value. The problem affects mainly pigs and poultry; ruminants are generally more resilient. This is largely because of their different heat loss strategies. Pigs can only lose heat effectively by wallowing. In the UK pig deaths in transit (DOAs – dead on arrival) are particularly a problem above average daily temperatures of about 18°C. This means that the number of deaths in transit is higher in the summer months. Mortality is also higher on longer journeys and in genotypes of pig that show greater stress susceptibility. Stress susceptibility in pigs is associated with the so-called Halothane gene (Hal+). The gene is present at relatively high frequencies in some breeds, notably the Belgian Pietrain, some strains of Landrace and meat-type hybrids, and is closely linked to genes that promote leanness and muscularity, so carcasses from these breeds have little fat and show desirable high conformation. Overall, the average mortalities in transit in the UK are about 0.1% for pigs and 0.02% for sheep. These contrast with the much higher level (0.2%) found in broiler chickens.


Methods used to handle animals

Animals need to be moved from and into pens, along races and passageways and on to vehicles. Vehicles must have their own unloading system. Usually this is formed from the tailboard, which acts as an external ramp, and internal ramps to access the higher decks in multi-tiered transporters. Animals find negotiating steep (>20° to the horizontal) ramps difficult. In particular, pigs do not climb or descend ramps very easily or willingly. Some transporters are therefore fitted with hydraulic platform lifts instead of ramps. The legislation prescribes maximum angles for vehicle ramps: 29° for external and 33° for internal ramps. These are, however, far steeper than is realistic.


There are recommended ways of handling animals, in particular making use of their natural behaviour patterns. For example, sheep have a well-developed, strong following behaviour. The legislation prescribes that no excessive force may be used to move animals and there must be no lifting or dragging by the horns, legs, tail or fleece. Animals must not be hit with sticks. The use of electric goads is strictly limited: they may be used only on the hindquarters of cattle over 6 months old, or on adult pigs which are refusing to move forward when there is space for them to do so. The shocks must be for no longer than 2 seconds and successive shocks must be adequately spaced out.


Poor handling can lead to animals slipping and falling and bumping into obstacles. This results in bruising or internal haemorrhages. By analogy with human experience, bruising is painful and therefore has welfare implications. It also damages the appearance of a carcass and may therefore lead to downgrading. Extensive bruising may require trimming, leading to weight loss and therefore direct economic loss. Bruising is always higher in the carcasses from animals sold via live auction markets than in those sent directly from the farm to slaughter, partly because the handling they receive is often poorer and partly because they must be handled more.


Segregation of animals in transit

Some animals are naturally incompatible: if mixed they fight, leading to injury. A particular and common problem is fighting caused by the mixing of pigs that have been reared in separate pens. This is stressful to them and leads to unsightly lacerations on the carcass and poorer lean meat quality. The problem is commoner in entire males (boars) compared with gilts or castrates. Mixed groups of young bulls will also fight, leading to bruising and reduced meat quality. The Legislation specifies various animals that must be segregated during transport to prevent serious injury or suffering, including bulls over 10 months old unless reared in compatible groups or accustomed to one another. Mixing of horned and unhorned cattle is generally proscribed and certainly not recommended.


Deprivation of food and water

Some period of food withdrawal before slaughter is desirable to reduce gut contents and therefore the chances of contamination of the carcass at evisceration if the distended gut is accidentally cut or broken. Pigs do not travel well on a full stomach, and mortality is higher in pigs fed too soon before loading. However, water should be available to animals at all practicable times. Long periods without food reduce live weights and carcass yields, a loss referred to as ‘shrinkage’ in North America. They also lead to hunger and hence poor welfare. A compromise therefore needs to be struck between the benefits and disadvantages of longer and shorter pre-slaughter fasting times.


PSE and DFD meat

PSE meat occurs in pigs. The meat is very pale, soft in texture (in the raw state) and exudative, meaning that it is wet in appearance and loses a lot of drip on cutting and during storage. The condition is caused by acute stress at slaughter, which speeds up the metabolism of the muscles, specifically glycolysis, immediately post-mortem. The resulting rapid acidification, at a time when the carcass is still hot, denatures some of the muscle proteins so that they lose bound water, leading to the characteristic changes seen subsequently. A major cause of PSE is the stress associated with moving them through race-restrainer systems immediately before they are stunned if this is carried out thoughtlessly or with excessive coercion. However, even when handled carefully at slaughter, stress-susceptible pigs tend to produce a high frequency of carcasses that show PSE meat.


DFD meat can occur in all species. In cattle it is often referred to as Dark Cutting Beef (DCB). The meat is very dark in colour, firm in texture and dry or even sticky to the touch. DFD is caused by chronic stress pre-slaughter that depletes muscle glycogen levels. This limits the degree of glycolysis, and therefore acidification, post-mortem. DFD meat is therefore characterized by a high ultimate pH, so it tends to be prone to spoilage, partly because this high pH promotes bacterial growth, and partly because the deficiency of glycogen and other carbohydrates encourages the growth of bacteria that break down nitrogen-containing compounds such as proteins. This produces very unpleasant putrefactive smells. The high pH means that the proteins do not denature and retain their high water-holding capacity, so the meat surface is dry. Examples of stresses that cause DFD are prolonged food deprivation, transport fatigue and the fighting that often occurs between unfamiliar animals, especially pigs and young bulls.


Very occasionally, pig carcasses apparently show both PSE and normal, DFD and normal, or PSE and DFD characteristics in adjacent parts of the musculature. This is referred to as ‘two-toning’. It is difficult to explain in physiological terms but probably reflects differences in the inherent biochemistry of different muscles and how actively they have been used in the animal. So, red muscles, which have more oxidative fibres, tend to be prone to DFD and white muscles, which have a more glycolytic metabolism, are more susceptible to PSE.


Both PSE and DFD meat are discriminated against by consumers and have poor eating quality as well as appearance. They also both reflect poor animal welfare because they result from stress.


The spread of disease

The movement of animals from farm to slaughter has obvious implications for the spread of disease, particularly if they pass through one or more auction markets in the process. The stresses associated with handling and transport may additionally increase the animal’s susceptibility to infection by compromising the function of its immune system. When animals are held in lairage there is also the danger of rapid cross-infection of healthy individuals from infected ones by pathogens such as salmonellae. The spread of disease between animals may well compromise their welfare, and the spread of pathogens potentially compromises meat hygiene, and therefore quality.


Further Reading

Mcnally, P.W. and Warriss, P.D. (1996) Prevalence of carcass bruising and skin-marking between cattle bought from different live auction markets. Veterinary Record 140, 231–232.


Warriss, P.D. (1992) Animal Welfare – Handling Animals Before Slaughter and the Consequences for Welfare and Product Quality. Meat Focus International, July 1992, CAB International, Wallingford, UK, pp. 135–138.


Warriss, P.D. (1994a) Ante-mortem handling of pigs. In: Cole, D.J.A., Wiseman, J. and Varley, M.A. (eds) Principles of Pig Science. University of Nottingham Press, Nottingham, UK, pp. 425–432.


Warriss, P.D. (1994b) Ante-mortem factors influencing the yield and quality of meat from farm animals. In: Jones, S.D.M. (ed.) Quality and Grading of Carcass of Meat Animals. CRC Press Inc., Boca Raton, Florida, pp. 1–15.


Warriss, P.D. (1995) The welfare of animals during transport. In: Raw, M.-E. and Parkinson, T.J. (eds) The Veterinary Annual, vol. 36. Blackwell Scientific Publications, Oxford, UK, pp. 73–85.


Warriss, P.D. (1998a) Choosing appropriate space allowances for slaughter pigs transported by road: a review. Veterinary Record 142, 449–454.


Warriss, P.D. (1998b) The welfare of slaughter pigs during transport. Animal Welfare 7, 365–381.


Warriss, P.D. (2000) Meat Science: an Introductory Text. CAB International, Wallingford, UK, 312 pp.


Warriss, P.D. (2003) Optimal lairage times for slaughter pigs. Veterinary Record 153, 170–176.


Weeks, C.A., Mcnally, P.W. and Warriss, P.D. (2002) Influence of the design of facilities at auction markets and animal handling procedures on bruising in cattle. Veterinary Record 150, 743–748.



4.2 Food Chain Information (FCI)


The Role of FCI

Based on appropriate and detailed information on pre-history of animals intended for slaughter, as well as on ante-mortem inspection findings, they can be categorized into suspect animal (posing a higher public health risk) and non-suspect animal (posing a lower risk) groups before arriving at the abattoir – or at least before slaughter. Such pre-history information should comprise all relevant data from birth, through all stages of rearing and up to the day of slaughter, and is called ‘Food Chain Information’ (FCI).


The higher- and lower-risk animal groups should be handled separately (during transport, lairaging and slaughter/dressing) so as to avoid cross-contamination of the latter from the former. During ante-mortem inspection at the abattoir, the initial FCI-based categorization of the animals into the two risk categories should again be re-evaluated in the light of any relevant findings. In cases where animals pre-categorized into the low-risk group (based on FCI) show any abnormalities potentially relevant for public health, they should be moved into the higher-risk category. With respect to post-mortem inspection (see Chapter 6), all higher-risk animals, understandably, would require detailed examination – including laboratory testing if needed, whilst lower-risk animals could be subjected to a simplified inspection system.


Main elements of FCI

Animal production systems can be divided into so-called ‘integrated’ and ‘non-integrated’ systems. Integrated animal production systems have recently been defined by relevant expert groups (Anon., 2004), and the criteria can be divided into two main groups: (i) they must operate by using Good Farming Practice (GFP), Good Hygiene Practice (GHP) and Hazard Analysis and Critical Control Points principles; and (ii) they must have quality assurance systems in place ensuring control over, and information availability about, aspects indicated below.


Identification, movement and traceability

Systems must be in place to record animal movements and to identify animals individually. Problems with individual identification exist particularly with sheep, but are expected to be resolved in the near future. Movement records must include a residency period to qualify for Farm Assurance status (see later). Currently, in the UK, this is 90 days for beef and 60 days for lamb. Generally, animals with higher movement frequencies should be considered as posing higher epidemiological risk.


Epidemiological intelligence

Monitoring and surveillance programmes provide data on existence and relevant changes in disease prevalences and zoonotic agents in animals. Epidemiological intelligence to be used for FCI includes any relevant baseline information and/or risk assessments available. The EU Directive 2003/99/EC on monitoring zoonoses and zoonotic agents at all points along the food chain became mandatory for all EU member states in June 2004. The exchange of relevant information is two-way, originating from each member state, having been digested by the EU and then distributed to relevant veterinarians and other public heath officials in all EU member states. In addition to locally available epidemiological intelligence information, these EU-managed data will be very relevant for FCI purposes.


Farm animal management

Relevant information must be gathered from each farm supplying animals, enabling proper analysis of the risks presented by the livestock. Naturally, animals must be well managed to good standards of husbandry and welfare by competent stockmen. Farm production data must be analysed properly and cover a wide scope of livestock production practices, including the frequency of herd or flock inspection, management and treatment of stock, surgical operations, dehorning and disbudding treatments, the management of neonate animals, the use of exposed grazing areas and dog control.


Environment and hygiene management

There must be on-farm systems to prevent pollution of the environment and potential re-cycling of hazards via the environment back to the animals. Naturally, this must involve detailed analysis of animal waste (slurry, dirty water, farmyard manure, etc.) storage, treatment and disposal. Methods and associated appropriate records for casualty stock disposal and isolation facilities for sick animals must be assessed. The cleanliness of stock at marketing should be known, as should methods and associated appropriate records for dog worming and sheep dip disposal. Overall farm biosecurity (e.g. movement of animals, people and vehicles, vermin) plays an important role in protecting public health.


Animal feed composition, storage and use

Animals must be fed appropriate feed which has been stored correctly. Contaminants and residues in animal feeds can ultimately be found in meat derived from stock which has eaten contaminated feeds. Therefore, knowledge of feed suppliers, feed composition and declarations, feed transport systems and whether the feeds have been examined for public health hazards must be obtained and analysed. Attention must be paid to the biosecurity of feeds stored on-farm, since pathogen-free feeds can become contaminated via contact with vermin, wild birds or insects if stored inappropriately on-farm.


Housing and handling facilities

Facilities must be adequate to provide safe housing, sufficient for the handling of stock. The structure and size, lighting and electrical installations and cleaning routine should be considered.


Production parameters

Good production parameters (e.g. growth rate, feed conversion rate and similar) normally indicate general good health and welfare of the animals.


Farm quality assurance in the FCI context

Many quality assurance schemes operate in different countries. One example is the Assured British Meat (ABM) scheme, which will be used here. ABM has around 23,000 members producing cattle or sheep; around 75% of cattle and 60% of sheep slaughtered in the UK come from ABM-assured farms. ABM membership effectively is an ‘unwritten’ condition for success on the market, since large retailers will only purchase meat from abattoirs slaughtering animals from ABM-assured farms. In practice, the ABM scheme involves independent on-farm inspections (10% of inspections are unannounced). A negative inspection results in loss of certification, which must be re-applied for. Naturally, the farm business stands the cost incurred.


The ABM scheme has numerous farm quality assurance standards, including (as at 2004):


• animal identification and movement: 3 standards;


• farm management: 20 standards;


• management of the environment and hygiene: 8 standards;


• animal feed (composition, quality, storage): 9 standards;


• animal husbandry conditions: 10 standards; and


• medications and veterinary treatment: 12 standards.


These standards are available from the ABM scheme directly, or from their website, and are being continually updated.


Herd health plans

Herd health plans, and related data, are one of the most relevant considerations form the FCI perspective.


Medicines and veterinary treatment

Medicines and treatments, posing a risk from residues in edible tissues, must be administered in an appropriate manner and all relevant records kept. Medicines must be used appropriately, with proper respect of withdrawal periods and safe, environmentally friendly storage and disposal.


Operative aspects of the food chain information (FCI) system, in the context of meat inspection

Operative aspects of the FCI are still under development, with the main points being considered and approved from practical, regulatory and public health aspects. Operators must deliver the necessary FCI to the Official Veterinary Surgeon (OVS), preferably through an information technology (computer) system. The FCI should be received 24 h before anticipated delivery of the animals. This is necessary to avoid unnecessary transport of animals which would not otherwise be accepted for slaughter. If FCI is not received from the holding or farm, the animals should not be accepted on the abattoir premises, so withholding of FCI will have serious consequences.


Exceptions to the standard provision of FCI may apply if appropriate data have already been provided through a recognized, validated and audited Farm Quality Assurance scheme. Some small farmers may not be able to provide appropriately detailed FCI: their position is currently under discussion. Any information relevant to public health must be relayed to the OVS at least 24 h before ante-mortem inspection, in addition to the FCI.


If no FCI is available the OVS must be informed; only the OVS can permit slaughter of animals without FCI. In such case, final judgement on fitness of the meat must be pending and the meat must be stored separately.


If FCI is available, but not provided sufficiently in advance (24 h), the animals must be killed separately, since the risks to public health they represent cannot be appropriately determined. If storage space is unavailable, meat slaughtered without suitable analysis of FCI could be even declared unfit for human consumption.


FCI should flow not just from farm to abattoir, but also as feedback from abattoir back to the farm of animal origin. Post-mortem inspection data, as part of FCI, will provide very valuable information about animal health.


In addition, FCI can help to modernize meat inspection (refer to later chapters) in which public health hazards are controlled – but physical meat inspection handling (palpation, incision) is reduced so as to reduce microbial cross-contamination.


The following responsibilities are envisaged for those involved in FCI and subsequently modernized meat inspection:


1. Official Veterinary Surgeons


• use FCI to categorize animals according to the public health risk they pose;


• carry out ante-mortem inspection;


• assess animal welfare;


• supervise post-mortem inspection;


• assess and audit GHP- and HACCP-based systems within the abattoir;


• take samples as necessary for laboratory examination; and


• BSE/TSE controls (e.g. SRM).


2. OVS Auxiliaries (trained)


• Carry out post-mortem inspection in the presence of OVS (except in small or poultry abattoirs).


3. Abattoir staff (trained)


• Staff should have the same duties as OVS Auxiliaries, but only within entirely integrated systems (primarily pork or poultry).


Further Reading

ABM (2005) www.abm.org.uk (accessed November 2005).


Anon. (2000) Opinion of the scientific committee on veterinary measures relating to public health on revision of meat inspection procedures. European Commission, Health and Consumer Protection Directorate-General, Brussels.


Anon. (2001) Opinion of the scientific committee on veterinary measures relating to public health on identification of species/categories of meat-producing animals in integrated production systems where meat inspection may be revised. European Commission, Health and Consumer Protection Directorate-General, Brussels.


Anon. (2003) Directive on the Monitoring of Zoonoses and Zoonotic Agents. Official Journal of the European Union L325, 31–40.


Anon. (2004) Regulation (EC) No. 854/2004 of the European Parliament and of the Council laying down specific rules for the organisation of official controls on products of animal origin intended for human consumption. Official Journal of the European Union L139, 206–319.


Johnston, A.M. (2000) HACCP and farm production. In: Brown, M. (ed.) HACCP in the Meat Industry. Woodhead Publishing Ltd, Cambridge, UK.


Maunsell, B. and Bolton, D.J. (2004) Guidelines for Food Safety Management on Farms. Teagasc – The National Food Centre, Dublin.



4.3 Ante-mortem Inspection


ALISON SMALL


Introduction

This chapter outlines the process of pre-slaughter inspection and evaluation of animals presented for processing for human consumption.


The roles of the veterinarian at the pre-slaughter point include protecting the public from food-borne disease and zoonoses, protecting the slaughter staff from zoonoses, protecting animal health through surveillance for serious and Notifiable Disease, and also protecting animal welfare through monitoring transport conditions, ensuring fatigued animals are allowed sufficient rest, separating bulls from heifers, polled animals from horned animals, and taking appropriate action regarding injured and infirm animals. Ante-mortem inspection aims to sort animals into three broad categories: those that can progress to slaughter normally; those that must be removed from the food chain; and those that need further, detailed post-mortem examination or require to be processed separately from the normal kill. The ante-mortem inspection should take into consideration information gathered from the holding of origin, as well as a visual assessment of the animal in motion and at rest during the 24 h period just prior to slaughter.


The ante-mortem inspection must be carried out under adequate natural or artificial light, and is an important part of the process involved in the production of wholesome, safe meat. As well as providing an assessment of the welfare status of the animal, it is an excellent opportunity for Notifiable Disease surveillance. However, its main aims are to gather clinical information which will assist in the final judgement of the resultant carcass, and to remove from the slaughterhall animals which should not be processed for human consumption. Ante-mortem inspection of the casualty animal often extends to clinical examination of the subject, in order to formulate a considered opinion on the fitness of that animal for human consumption. An animal that has been presented to the veterinarian already dead cannot be subjected to ante-mortem inspection, so cannot be processed for human consumption


Certain conditions, such as clinical tuberculosis, septicaemia or Bovine Spongiform Encephalopathy (BSE), automatically render the carcass unfit for human consumption. If an animal exhibits clinical signs of any of these conditions, it will fail the ante-mortem inspection. Animals containing residues of pharmaceutical agents also may not enter the human food chain. When the veterinarian carries out the ante-mortem inspection, it is important to bear in mind the clinical history of the animal, and also the health status of the farm of origin. It is also important that the details of the inspection or examination are recorded and that these records accompany the body to the abattoir, as they are very useful in the final judgement of the resultant carcass. If a body arrives at the abattoir with insufficient information to allow this final judgement, it may be rejected as high risk.


Another major consideration during the ante-mortem inspection is the issue of microbiological hazards. The major issue in the production of wholesome, safe meat at the present time is food-borne disease, caused by organisms such as Salmonella species, Campylobacter species, Listeria species and pathogenic and toxigenic strains of Escherichia coli. These organisms are carried asymptomatically in the intestines of livestock, and excreted in faeces. As animals age, they are more likely to have encountered these organisms, and as such, the prevalence in older stock is greater than in younger stock. Stress also increases the shedding of these organisms in the faeces, so a stressed animal, for example a casualty animal, is more likely to be shedding the organisms, and thus poses a high risk to its associated carcass, and to the carcasses of other animals processed at the same time as the carrier animal.


In order to protect the slaughterhall environment, and the carcasses therein, animals that are excessively dirty are not permitted to be processed for human consumption. The UK Meat Hygiene Service (MHS) uses a five-point system of scoring of livestock cleanliness, in which 1 is show-condition cleanliness, dry animal and 2 is a dry animal with small amounts of adherent bedding. Animals of scores 3, 4 and 5, with increasing dirtiness and wetness are rejected at ante-mortem inspection, and must be cleaned prior to being presented once more for ante-mortem inspection (Figs 4.1, 4.2).


The Casualty Animal

Within livestock practice, the casualty animal often poses challenges in the form of a complex decision-making process. Often, the producer has already made the first decision, that the animal is to be destroyed rather than treated, before the veterinarian is summoned. The veterinarian then has a duty both to that animal, on welfare grounds – to prevent its continued suffering, and also to the producer – to provide sound advice on the remainder of the process. Poor advice could lead to increased or unnecessary cost to the producer, or to failures to protect public health and animal welfare. There are two main classes of casualty animal, those that are fit to transport and those that are not. The veterinarian must assist the producer to rapidly decide in which class of casualty the animal belongs, following a decision-making process such as that outlined in Fig. 4.3, and act accordingly. Any delay will impact upon the welfare of the animal concerned. When the outcome of the decision has been reached, there is then a duty to ensure that the animal is destroyed without undue delay, in a manner that is humane and appropriate to the circumstances and to the species.


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Dec 15, 2017 | Posted by in GENERAL | Comments Off on Pre-slaughter Phase

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