abattoir a building for the slaughter of animals and initial preparation of carcases for human consumption, also commonly called a slaughterhouse.
acceptability see overall acceptability, meat quality, appearance, muscle colour, fat quality, eating quality.
ad libitum feeding allowing free access to food, thus allowing animals to eat as much as they wish, as distinct from restricting an animals access to feed.
ageing (conditioning, maturation, or hanging) the holding of carcases or primal joints at refrigerated temperatures (0 to 4 °C) to improve eating quality.
aitch-bone hanging (pelvic suspension, hip suspension) is the process of suspending the carcase from the hip, via the hole in the aitch bone (obturator foramen of the os coxae) as opposed to suspension by the Achilles tendon.
androstenone the male sex hormone implicated in the generation of boar taint in pig meat .
animal welfare is defined, in Bailliére’s Comprehensive Veterinary Dictionary, as the avoidance of exploitation of animals by man by maintaining appropriate standards of accommodation, feeding and general care, the prevention and treatment of disease and the assurance of freedom from harassment, and unnecessary discomfort and pain. In assessing animals’ welfare it is normal to use the concept of the ‘five freedoms’ as revised by the Farm Animal Welfare Council in 1993. These are: freedom from thirst, hunger and malnutrition; freedom from discomfort; freedom from pain, injury and disease; freedom to express normal behaviour; freedom from fear and distress.
ante-mortem inspection performed or occurring before death (slaughter).
aroma (odour) the sensory perception of attributes of substances brought about by the sensation of volatile chemicals in the nose and pharynx. Aroma is one of the major eating quality attributes of meat.
backfat the subcutaneous fat layer located between the lean and the rind along the back (loin) of an animal, used as an index of the degree of fatness in pig carcases.
backfat thickness the depth of backfat (subcutaneous fat) including the rind, as measured from the lean at defined positions on the back.
bacon meat from the pig which has been preserved by curing with salt and nitrite or nitrate.
baconer pigs destined for bacon production, typically slaughtered at weights of between 80 to 100 kg liveweight (thus 60 to 75 kg deadweight).
beef the meat of all cattle, other than from the young calf which is referred to as veal.
beef cattle animals reared solely for the purpose of beef production.
bleeding see exsanguination.
boar un-castrated male pig.
boar taint an abnormal odour and flavour occasionally generated during cooking of meat from pigs, particularly heavy entire male pigs. Such taints result from two naturally occurring strong smelling compounds stored in the fat. These are the male hormone androstenone, and the breakdown products of the amino acid tryptophan, namely indoles, particularly skatole (perceived as faecal odour).
bobby calf calf slaughtered at a few days of age. The meat from such animals is classed as veal.
bone is the hard, rigid structural tissue that forms the skeleton of an animal. Muscles are attached to bones by tendons.
boning process of removing meat from the bones of a carcase, the meat of which is then termed “boned-out”.
bovine the Latin term pertaining to, characteristic of, the ox or cattle.
boxed beef normally boned-out beef forequarters and flanks sold in boxed form (see boning).
brine a salt solution used in the curing of meat which is normally based upon sodium chloride and sodium nitrite, however other ingredients are also included depending on the curing process.
bruising is the discoloration and actual haemorrhage at the site of an injury, and can seriously reduce the value of a carcase. Careful handling of the animals at loading, during transportation and in lairage will reduce the incidence of bruising.
bull uncastrated male cattle (see castrate), often referred to as an entire.
bullock castrated male bovine, often referred to as a steer.
by-products non-carcase parts of the animal, both edible (e.g. liver) and inedible (e.g. hide).
calf young cattle from birth to weaning. A female calf is referred to as a heifer calf, and a male calf a bull calf. The meat obtained from calves is termed veal. A calf slaughtered at only a few days of age is termed a bobby calf.
canning of meat is a means of long term preservation by the use of heat to sterilise (destroy all micro-organisms and their spores). The meat is hermetically sealed into the can and subjected to heat.
carcase (carcass) the body of an animal killed for meat. The term usually applies following the removal of various parts from the dead body (dressing).
carcase classification the placing of carcases into categories, whether as part of an EU scheme or otherwise, designed to indicate their commercial value. Normally the classes are related to the lean meat content, retail yield or quality attributes of the meat.
carcase composition refers to the proportion of the various tissues (fat, lean, bone etc.) in the carcase, or to the amount of chemical constituents contained in the carcase.
carcase conformation see conformation, conformation class.
carcase weight (hot/cold) the weight (kg) of the body of an animal, dressed according to a defined specification, at the end of the slaughter line (within 45 minutes of slaughter for pigs and within one hour of slaughter for cattle and sheep) is termed hot carcase weight. Carcase weight can also refer to the weight of the carcase of an animal following chilling (thus cold carcase weight).
carcase yield see killing out percentage.
cartilage supporting connective tissue consisting of mainly collagen. Cartilage present in meat is often termed gristle.
castrate a male animal that has been castrated (see castration).
castration the act of removing, or rendering dysfunctional, the testes of a young male animal, thus making the animal incapable of reproduction and, in many cases, modifying the animal’s behaviour. Both surgical and “bloodless” physical methods of castration are legal in Britain but strict age limits are defined.
cattle bovine animals. Domestic cattle are all members of the Bos genus of which there are two species; Bos taurus which refers to European or British breeds of cattle; and Bos indicus, the Zebu or oriental domestic cattle. Cattle used within the UK tend to be either specialist beef cattle or dairy cattle breeds.
cereal beef young cattle ready for slaughter at 10 to 12 months of age, commonly referred to as “barley beef”. These cattle are fed a mainly cereal diet (e.g. cereals plus a protein supplement) and housed indoors throughout their lives.
chilling is the reduction in temperature of a carcase. It is used to restrict the growth of pathogens and spoilage micro-organisms in meat and hence reduce deterioration. The chilling process generally involves placing carcases in conditions of 0 to 5 °C within one hour of slaughter.
clean cattle heifers, young bulls or steers, as distinct from cull cows or mature bulls. Also known as prime cattle.
clean sheep female ovines that have not lambed or reached a state of pregnancy, and male ovines that do not possess “ram characteristics”.
clean pig gilts, young boars and castrates, as distinct from cull sows or mature boars.
CO2 stunning (carbon dioxide anaesthesia) a method used to render an animal unconscious for slaughter. CO2 gas (at least 80% CO2) can be an effective alternative to electrical stunning.
cold shortening occurs when muscles are cooled rapidly after slaughter while still in a pre-rigor condition. This causes the sarcomeres within the muscle to shorten, which results in a very appreciable reduction in the tenderness of meat.
collagen is the chemical which forms the bulk of the connective tissue within meat. The collagen component of muscle is fundamental in determining the structure of meat and is a major determinant of the eating quality, particularly tenderness of meat.
colour see muscle colour, fat quality.
condemnation (condemned meat) meat deemed to be unsafe for human consumption, as condemned by veterinary surgeons or meat inspectors at the abattoir. Once a carcase or part of it is condemned, it must be kept separate from meat intended for human consumption, in a room designated solely for this purpose within the abattoir. Strict regulations are enforced to ensure condemned carcases are disposed of in a safe manner.
conformation the overall thickness of muscle and fat in relation to the size of an animal’s skeleton, i.e. the “shape” of the carcase profile and degree of muscularity.
conformation class is the subjective score given for the conformation of a carcase and is used in the MLC methods of beef carcase classification and sheep carcase classification. The MLC methods comply with the EU carcase classification schemes for these species in which there are five main classes used: E, U, R, O and P. In some countries an optional S grade is used for superior conformation animals.
connective tissue the components of animal tissues responsible for structural integrity. In meat it is mainly present as collagen and to a lesser extent elastin.
contamination bacterial or chemical contamination of the carcase can be a serious cause of deterioration and spoilage of meat during storage. Although chemical contamination can take place prior to slaughter, it is generally accepted that muscle is sterile in a healthy living animal, thus it is only when the animal is killed and the carcase handled, will the external surfaces of muscles be exposed to contamination by bacteria.
cooked meat refers to meat that has been rendered suitable for consumption by a suitable heating process.
cooking loss is the reduction in weight of meat during the cooking process. Such losses consist of moisture and lipids from both the lean and fat tissues during cooking.
cow a female bovine animal which has produced a calf. Prior to producing their second calf these animals are commonly referred to as heifers.
cull breeding animals of any species slaughtered at the end of their productive lives. The term most commonly refers to dairy cattle or suckler cows, sows and ewes.
curing (cured meat) a method of preserving and thus extending the shelf life of meat (particularly cured pig meat product bacon and ham) which includes treating with a solution of salt and nitrite or nitrate.
cutter a term given to a pig grown to produce a general purpose carcase, i.e. its carcase may be cut into sections which may be used for bacon, pork or processing respectively. Such animals are normally slaughtered at between 70 to 90 kg liveweight (50 to 70 kg deadweight).
dairy beef beef produced as a by-product of the dairy industry from calves of dairy cattle. The calves produced from dairy cattle tend to produce lean carcases with poor conformation in comparison to beef breeds.
dairy cattle cattle of a breed specifically bred and kept for milk production. In the UK the Friesian and Holstein breeds are the most widely used dairy cattle.
dam female parent of an animal.
de-hairing the removal of hairs from a pig carcase. The carcase is normally scalded by plunging in a vat of water held at about 60 °C for about 5 minutes so as to soften the skin and bristles (hairs). Following scalding, the bristles and superficial layers of skin are removed, either by the use of a machine with soft flails that beat the carcase or manually by scraping with a sharp knife.
de-hiding the process of removing the skin (hide) of cattle as carried out following slaughter. The hide is separated from the carcase normally mechanically. A carcase with a skin that does not easily lift from the subcutaneous tissue is said to be “hidebound”. This particularly occurs in extremely lean animals due to an absence of fatty tissue beneath the skin.
deadweight the weight of the carcase after dressing. Also referred to as dressed weight.
dressed weight the weight of the carcase following the process of dressing.
dressing the process of removing various parts of the body of an animal following slaughter.
E. coli (Escherichia coli) a species of bacteria found in the intestines of animals. Pathogenic strains can cause urinary and digestive infections in humans. E. coli infections of meat are only likely if poor handling of the carcase, particularly the guts or hide, is carried out after slaughter.
eating quality of meat refers to the organoleptic factors influencing consumer acceptance and enjoyment of the product. The main eating quality attributes of meat are tenderness, juiciness, flavour and aroma.
electrical stimulation a method of improving the tenderness of meat by the application of an electric current to the carcase following slaughter.
entire a male animal that has not been castrated and therefore retains the testicles in the scrotum and is capable of reproduction.
enzyme refers to any soluble protein that acts as a catalyst, increasing the rate at which a chemical reaction occurs in the body. Animals can contain up to 10,000 different enzymes.
evaporative weight loss a loss of water from the carcase, particularly during the chilling process, through its conversion to a gaseous form. Evaporative weight loss can be reduced by rapid chilling.
ewe female sheep which has lambed or reached a stage of pregnancy which will depreciate the carcase value.
exsanguination the technique used to drain the blood from the carcase of an animal at slaughter. Also known as sticking or bleeding. In the UK, usually immediately following stunning, the animal is cut across the throat by a trained person, ensuring that at least one of the carotid arteries is severed.
fat (i) the adipose (fatty) tissue found in the body. The visible adipose tissue in prepared meat is known as visual fat.
(ii) a substance which is insoluble in water but soluble in organic solvents such as ether (also termed lipid). The amount of fat determined by laboratory analysis using one of these solvents is known as chemical fat.
The amount and the appearance of the fat both within (intermuscular fat and intramuscular fat) and surrounding (subcutaneous) the lean tissue of a carcase, is an important determinant of attractiveness to the modern day consumer.
fat class a subjective score given for the degree of fat cover of a carcase, used in the MLC methods of beef carcase classification and sheep carcase classification. There are five main classes (1 to 5) according to fat cover, used in these classification schemes.
fat quality desirable fat has been described as fat which is firm but not too hard and of a white colour in pigs and creamy-white colour in cattle and sheep.
fatty acids are organic acids which occur in fat. The distinctive feature and major compositional characteristic of each fat is determined by its fatty acid composition. Fatty acids can be either saturated (all carbon to carbon bonds within the molecule are single) or unsaturated (one or more carbon to carbon bonds are double bonds) and this is a major determinant of the melting point which determines the firmness of the tissue at a particular temperature of the fat. The greater the saturation, the higher the melting point.
feed conversion ratio (FCR) is the number of kilograms of feed required to produce 1 kg of liveweight gain. Also known as feed conversion efficiency (FCE).
finished to rear an animal to a suitable weight and condition for slaughter. An animal is referred to as “finished”, based on subjective assessments of conformation and subcutaneous fat deposition. An animal in the later stages of the growing period (finishing period) is often referred to as a finisher.
flavour is one of the eating quality attributes of meat. It is the combined result of the senses of taste and smell (aroma) and is notoriously difficult to evaluate.
freezing the process of reducing the temperature of meat to a level at which most of the water within it is converted into ice for the purpose of reducing bacterial growth and biochemical deterioration during extended storage. EU legislation states that this temperature must be –12°C or lower.
fresh meat is that which is unprocessed (i.e. in its original state). The fresh state is defined as that of a short shelf life perishable unprocessed food prior to perceptible evidence of physical, chemical or microbiological change by the Institute of Food Science and Technology.
FSA Food Standards Agency www.food.gov.uk
gilt young female pig. The term is most often applied until the production of the animal’s first litter, although it is also used until the first litter is weaned. A “maiden” gilt is a sexually mature female pig that has not yet been mated.
grading the categorisation of a carcase according to quality standards. Individual abattoirs may operate their own grading systems depending on their requirements. This will, in the UK, normally make use of the information supplied by classification. Grading attempts to assess some quality attribute against what the market demands. In contrast, classification simply allocates carcases to clearly defined classes without attaching a quality judgement.
grass silage beef beef produced from cattle (often bulls of dairy breeds) fed indoors on a diet of silage and cereals for slaughter at 13-17 months of age.
greaves during rendering raw by-products are cooked resulting in a fatty product called greaves. This product has recognisable parts of the animal (such as pieces of bone) and when squeezed in the hand tallow oozes out. Mechanical separation results in tallow and greaves with a lower fat content. This remaining greaves is then milled and dried resulting in meat and bonemeal.
growth is the progressive increase in size or number of cells of living things and is the basis of meat animal production. The relative patterns of growth of animal tissues (bone, muscle, fat) are similar in the three species. In each species, bone is an early developing tissue (grows most quickly when the animal is young), muscle intermediate, and fat late developing.
gut a term used to refer to the alimentary tract (stomach and intestines) of an animal (see gutfill).
gutfill refers to the food, digesta and faeces as contained in the animal’s gut. Gutfill is a major contributor to the variation found in killing out percentage.
Halal slaughter Muslim method of religious slaughter. The religious requirement is that only healthy and uninjured animals can be slaughtered for consumption. Stunning prior to slaughter is considered injurious by some Muslim officials and therefore is not carried out in all cases. Death is achieved by drawing a very sharp knife across the throat thus cutting both carotid arteries and both jugular veins with one stroke.
handling refers to the treatment of animals when they are moved by humans. The way meat animals are handled between the farm and the abattoir, and within the abattoir itself, has very important implications for both animal welfare and meat quality.
hanging see ageing, aitch bone suspension.
heifer young female bovine that has not produced a calf. These animals are often referred to as heifers following the production of their first calf until calving for a second time.
hide the skin of cattle as removed at abattoir.
hog a castrated male pig also referred to as a castrate.
hogg or hogget (i) young sheep (either male or female) slaughtered before any permanent incisor teeth have erupted. Under MLC’s sheep classification scheme hoggets are termed old season’s lambs. (ii) a live sheep between the time of weaning and its first shearing.
hot boning (hot de-boning) the separation of the bones from the meat in a carcase as carried out immediately following slaughter, before the carcase has been chilled and the meat time to set.
hot conditioning very slow chilling of the carcase by holding at air temperatures above conventional chiller temperatures for a period of time before lowering of the carcase temperature to normal refrigeration temperatures.
hot shortening (rigor shortening) is the contraction of muscles seen when muscle goes into rigor mortis at temperatures above 20°C. Hot shortening generally produces low to moderate shortening and reductions in meat tenderness, in comparison to cold shortening.
in-calf used to describe a cow or heifer when pregnant.
in-lamb used to describe a pregnant ewe.
in-pig used to describe a pregnant sow.
intermuscular fat is the fatty tissue formed by depots of fat cells (adipocytes) situated between the muscles.
intramuscular fat is the fat found within the muscles. It comprises intrafibre fat and depots of fat cells between the muscle fibre cells and bundles of muscle fibre cells. The intrafibre fat is lipid within the muscle fibres whereas the collections of fat cells constitute small depositions of adipose tissue. These visible depots within the muscle are known as marbling fat.
inverted dressing refers to a carcase dressing system used for sheep during which the animal is suspended from the fore legs, the hind legs or all four legs to suit each operation on the dressing line and ensure hygienic practise.
Jewish slaughter a method of religious slaughter in which animals are slaughtered while still conscious, termed Shechita slaughter. This method has much in common with Halal slaughter. In some countries it is a requirement of this slaughter technique to use a rotating casting pen to restrain the animal. The use of a casting pen is illegal in the United Kingdom. Slaughter is achieved by drawing a very sharp knife across the throat, thus cutting both carotid arteries and both jugular veins with one stroke. This slaughter may only be carried out by an approved slaughter-man of the Jewish faith who is usually a Rabbi. Only cattle, calves (see calf), sheep, goats, deer (see venison) and poultry are allowed to be killed for Jewish consumption.
jointing (cutting) the process of sectioning the carcase. Following splitting the carcase into sides, it is then cut into primal joints which is then followed by the process of cutting into retail cuts.
juiciness the sensory attribute of foods related to the perception of moisture in the mouth. Juiciness has two organoleptic components in meat. The first is produced by the release of water from the meat during the beginning of chewing, and the second is more sustained and due to the stimulatory effect of the meat on salivation. Juiciness can be influenced by flavour. Juiciness also plays a key role in the perception of meat texture, contributing between 10% and 40% to its variability.
kidney the kidneys are organs that filter blood plasma, re-absorbing water and useful constituents and ultimately excreting waste products and excess constituents. The kidneys are retroperitoneal, that is to say outside of the peritoneal cavity but are closely attached to the abdominal wall
killing out percentage (KO%) the dressed weight of a carcase as a proportion of the liveweight of the animal prior to slaughter. Typically killing out percentages vary between 45 and 55 % for ruminant species such as cattle and sheep. The KO% of pigs is higher (around 75 %) due to the relatively lower weight of the viscera and their carcases including the skin and normally the head and feet. Killing out percentage will vary within a species, due to factors such as amount of gut fill at slaughter determined by the timing of the last feed and water consumption prior to slaughter, the degree of fatness and the age of the animal (the ratio of gut to other body parts is greater in young animals).
knacker’s yard place of slaughter of animals unfit for human consumption. The carcases from such premises may be purchased by the pet food industry or may go to rendering.
lairage (i) area of an abattoir where animals are held (rested) before slaughter. A holding period may allow the animal to recover from the experiences of transportation and unloading, and thus adrenaline concentrations in the bloodstream to fall. An adequate lairage period will therefore help to ensure that following slaughter, the carcase pH falls. (ii) the time an animal spends in the area of the abattoir known as the lairage, see (i)
lamb (i) meat from young ovine animals. Note that the term “lamb” as part of the customary name of certain traditional meat products may refer to lamb, or to mutton, or to a mixture of these.
(ii) in the MLC carcase classification scheme, carcases of ovine animals are classified as lambs (those born and marketed within a year beginning the 1 January or born after the beginning of October in the year prior to marketing), old-seasons-lambs (other clean sheep with no permanent incisor teeth erupted) or mature sheep (clean sheep with one or more permanent incisor teeth erupted).
(iii) in other classification schemes different categories are used. For example, in Spain, lambs I are male or female butchers lambs under 12 months with a carcase weight of 12-13 kg and lambs II are male or female butchers lambs under 12 months with a carcase weight of 13.1-16 kg.
lean (lean tissue/lean meat) the skeletal muscle of the carcase, with all visible subcutaneous and intermuscular fatty tissue removed. When lean meat is separated from fat and other tissues with a butchers knife then some traces of fat may remain with the muscle. This type of lean meat can be referred to as knife separable lean.
lean meat percentage the percentage of the carcase that is lean meat. This is estimated in pig carcase classification by use of an optical probe or automatic recording probe.
liver a large dark red organ located in the abdomen. Its functions in the live animal include the filtration of blood and conversion of sugars into glycogen. The liver is important in carcase inspections carried out at the abattoir, as a good indicator of animal health problems.
liveweight a live animal’s weight. The rate at which an animal grows is termed liveweight gain and is usually expressed in kg/day.
marbling (fat) see intramuscular fat.
maturation see ageing.
meat generally refers to the flesh of mammals used as food by humans. Legal definitions of which tissues constitute meat do exist but the definitions vary according to the legal context and also whether or not the tissue is to be sold as raw meat or included in a cooked meat product.
meat and bonemeal the final high protein meal resulting from rendering after the extraction of tallow.
meat inspection the process of examining carcases post-mortem for evidence of disease or damage making the meat unfit for human consumption. Meat Inspection in the UK is a service under veterinary control operated by the Meat Hygiene Service and charged to the individual abattoir.
meat quality although there is no generally accepted single definition of the term “meat quality”, it is common to include at least hygienic, nutritional, suitability for processing, ease of handling, and sensory qualities of meat within this term. Some definitions of meat quality also include aspects of the perceived animal welfare of the system of production and even the environmental impact of that system.
MHS The aim of the Meat Hygiene Service is to safeguard public health and animal welfare through fair, consistent and effective enforcement of hygiene, inspection and welfare regulations. www.food.gov.uk/enforcement/meathyg/mhservice
MLC Blueprints these are guidelines incorporating the best state of the art practices and novel approaches to enhance the eating quality of British beef, pork and lamb to increase consumer satisfaction of these products.
modified atmosphere packaging (MAP) is the process by which meat is packed in a mixture of gasses designed to extend the shelf life of meat by inhibiting microbial growth. Normal aerobic microbial spoilage is inhibited and in some gas mixtures the oxidation of red oxymyoglobin to brown metmyoglobin is reduced.
muscle a tissue composed of bundles of elongated cells (muscle fibres) embedded in connective tissue and capable of contraction and relaxation. Generally attached to the skeleton, muscles use bones and joint as levers to bring about locomotion. The economic production of protein rich muscle (lean) tissue is the major objective of meat production.
muscle (meat) colour in red meats a bright red colour is perceived by consumers as being indicative of freshness. Myoglobin as the primary pigment responsible for meat colour. When meat is exposed to the oxygen in air, the purple-red myoglobin absorbs oxygen and is converted to bright pink oxymyoglobin. After prolonged exposure, oxymyoglobin is chemically oxidised to brown metmyoglobin, this process is often termed “browning”.
mutton meat from the carcase of an older sheep, especially that from a mature sheep.
myoglobin (Mb) a principal haem containing pigment in muscle tissue responsible for oxygen transport into the muscle and associated with muscle colour.
nutritional composition the proportions of the various macro-nutrients (fat, proteins, water, carbohydrate) and micro-nutrients (vitamins and minerals) of a food. Meat is a highly nutritious source of proteins and essential amino acids, fats and essential fatty acids, energy, vitamins (vitamin A and vitamin B12) and minerals (Iron and Zinc). The nutritional value of meat can, however, be affected by the method of cooking.
offal the low value edible or inedible soft tissues of a carcase removed during the dressing of the carcase of an animal killed for food. There are two main classes of offal. Green offal refers to the digestive tract and associated organs. Red offal refers to the more commonly consumed offal from the carcase such as the liver, kidney and heart.
outdoor pigs the UK pig industry has witnessed an increased number of breeding sows being kept in outdoor systems over the last ten years. Although these animals farrow outdoors in arcs (mobile shelters), the vast majority of the piglets produced are reared and finished in conventional indoor systems.
ovine the Latin term pertaining to, characteristic of sheep.
oxygenation the saturation of a substance with oxygen. For example, the oxygenation of purple-red myoglobin forms bright pink oxymyoglobin.
P2 (P1+P3) the probe positions, level with the head of the last rib, on a pig carcase from which backfat thickness is evaluated in the MLC method of pig carcase classification.
pelt the skin of sheep as removed at the abattoir which will include a wool covering. The amount of wool present on the skin will depend on the time of year the animal is slaughtered and whether shearing had taken place prior to slaughter. The amount of wool on a pelt will affect its value.
pelting the process of removing the skin (pelt) of sheep as carried out following slaughter in an abattoir. The process of pelting requires care if bacterial contamination of the carcase by the pelt is to be avoided.
pH is a value used to represent acidity or alkalinity of the muscle. The pH of muscle in the live animal is approximately 7.3. Muscle pH declines (becomes more acidic) rapidly following slaughter, as a result of the accumulation of lactic acid. Muscle colour is strongly related to pH. It is generally accepted that a higher pH is associated with increased tenderness. The influence of pH on meat tenderness has been shown to be related to the effect pH plays on the water holding capacity of meat, and that a higher water-holding capacity results in an increased tenderness. It is perhaps not surprising therefore that a higher ultimate pH also tends to be associated with an increase in juiciness. The pH of the muscle after slaughter has also been shown to affect the subsequent flavour of meat.
pig an animal of the porcine genus of which there are several species. It is a simple stomached non-ruminant. An entire male pig is called a boar and female pigs are termed sows or gilts, castrated male pigs are referred to as castrates, barrows or hogs.
pig carcase classification methods of pig carcase classification used in the UK are based on estimating carcase lean meat percentage from the carcase weight, muscle depth and backfat thickness. These methods involve taking carcase measurements with EU-approved measuring equipment: the Optical Probe or an approved automatic recording probe.
piglet pig (of either sex) from birth to weaning (between 3 to 8 weeks depending on system), also called a suckler or suckling pig.
pig meat meat derived from the porcine species. It is marketed as either fresh (or frozen) pork cuts, as cured sides or cuts (see curing), or for inclusion in a myriad of processed meat products.
pigment a term used to describe a substance that imparts colour to another substance. The pigments within a muscle are largely responsible for determining muscle colour. The major pigment of muscle is haem in myoglobin. To a lesser extent, carotenoid pigments also contribute to the colour of meat (particularly fat). The muscles from older animals generally have higher concentrations of pigment and are thus darker in colour than younger animals.
porcine the Latin term pertaining to, characteristic of the pig.
pork a general term for the pig meat usually used to refer to meat that has not been cured.
porker a somewhat outdated name given to a pig being reared for the production of pork. Historically pigs in the UK were slaughtered over a wide weight range with the lightest to the heaviest pigs being called porkers, cutters and baconers in turn. In recent years the weight range has narrowed markedly and these terms have generally fallen into disuse.
post-mortem meaning performed or occurring after death (slaughter). In contrast to ante-mortem.
post-mortem acidification describes the way the carcase pH changes from neutral (7.3) before slaughter, to acidic (approx. 5.5) within hours of slaughter.
poultry refers to farmed species of birds (eg chickens, turkeys, ducks).
primal joints see jointing.
prime cattle see clean cattle.
probe any sharp instrument used to measure a carcase characteristic by insertion. Examples include those used to measure backfat thickness, eye muscle depth and pH, and the fibre optic probe.
processed food having been treated in such a way as to change one or more of its properties.
proteins the name given to chemical compounds consisting of long chains of sub-units called amino acids. They are essential constituents of all living cells. The lean tissue of the carcase is comprised predominantly of muscle protein. Muscle protein growth is a balance between protein synthesis and protein degradation, with rates of synthesis exceeding those of degradation resulting in increased net lean tissue (protein) deposition. Approximately 25% of muscle mass is protein.
ram un-castrated male sheep (see castrate), often referred to as an entire or a tup.
red meat for MLC purposes red meat includes beef, lamb, pork. In certain contexts it may include game and other meats but would not include white meats such as poultry meat.
re-formed meat products which have the appearance of a cut, joint, slice or portion of meat are termed re-formed. This is achieved by the use of tumbling or specific alignment of fibres with or without the addition of finely comminuted meat or a meat emulsion to bind the pieces together, and then forming into shapes.
refrigeration the maintenance of temperatures at a level selected to reduce spoilage (especially bacterial spoilage), normally taken to be in the range 0 to 4 °C.
rendering the process of liberating the fat (lipid) from animals tissues. This is performed by heating the tissues to a temperature that achieves melting of the fat with subsequent collection and solidification of the molten fat. The heating can be either dry (dry rendering) or when water is present (wet rendering).
restricted feeding feeding of animals at a level lower than the amount they would eat given free access to food.
retail cuts portions of meat prepared for sale to the consumer in the raw state.
rigor (rigor mortis) the stiffening of a dead body (carcase). Skeletal muscle remains “alive” after the slaughter of the animal, until rigor mortis is complete. This increase in stiffness is brought about as a result of the muscle contractile proteins, myosin and actin locking together. When rigor is complete, the carcase is said to be set. The rate at which rigor occurs and is completed is dependant upon species, muscle fibre type, temperature, slaughter procedure and whether electrical stimulation of the carcase has taken place. Rigor is more rapid in pig muscles than beef and sheep, and in red muscles than those of predominantly white fibre types. Rigor is completed more rapidly at higher temperatures and also if electrical stimulation of the carcase has taken place. Muscles shorten as they go into rigor and the pH of the muscle will fall. Freshly slaughtered pre-rigor meat is tender but becomes tough at the onset of rigor mortis. Subsequently, as the meat passes through rigor mortis and the ageing process, it increases in tenderness.
rind the skin of a pig. Pig meat is often sold, and may be cooked, with the rind left on. Between the rind and the lean tissue is found a layer of subcutaneous fat.
ruminant an animal that has a stomach which is divided into four compartments: rumen, reticulum, omasum and abomasum. These animals characteristically regurgitate undigested food from the rumen into the mouth to be re-chewed (chewing the cud) and then returned to the rumen for further digestion. Cattle, sheep and goats are all ruminant species.
runners refers to the part of the small intestine of cattle, sheep and pigs that can be used to prepare casings although the small intestine of cattle cannot be used currently in Britain.
saleable meat that portion of the carcase which can be sold to the consumer. Saleable meat includes lean meat, fat, bone and other tissues (such as rind with pig meat). The amount of saleable meat will depend on the butchery practices involved, for example the sale of cuts bone-in or boneless.
seam butchery the preparation of cuts from a carcase based on cutting along the natural joins between muscles.
sex of an animal can have a considerable influence on its production characteristics such as growth rate and feed efficiency, and on carcase characteristics such as fatness and conformation. In addition, entire male animals (particularly pigs) can produce specific flavours in the meat and, as they approach maturity, males tend to produce meat which is tougher due to changes in connective tissue. Three sexes of meat animal can occur, male, female and castrate. Castrated animals divert energy intake into the synthesis of fat rather than lean and are less efficient in food conversion.
Shechita slaughter See Jewish slaughter.
sheep an animal of the ovine species. Sheep are ruminants. A mature female sheep is termed a ewe and a mature male a ram with their offspring referred to as lambs. An additional form of classification of breeds is on the basis of whether they have been bred for wool, milk or meat production characteristics.
shelf life of meat is the period of time on retail display that the product can be considered safe and of acceptable quality for human consumption. The length of this period will be determined by two main factors, microbial spoilage and colour stability. Shelf life of meat can be extended by the processes of curing and smoking.
shearling a sheep following its first shearing but before its second is called a shearling. It is assumed to refer to an uncastrated male unless some qualifying term is used.
shrinkage of meat is the weight loss that can occur during the processes of chilling, storage and cooking. This is caused by evaporative loss from the surface, a loss of water holding capacity and/or collagen shrinkage on cooking. The weight loss on chilling or storage is primarily water whereas cooking loss includes a proportion of fat.
sire male parent of an animal (see terminal sire).
skatole (3-methylindole) is a breakdown product of the amino acid tryptophan which has been implicated in the generation of boar taint in pig meat. This compound is deposited at higher levels in the fat of entire male pigs compared to either castrates or females. Increasing the level of digestible fibre in pig diets appears to reduce the concentration of skatole in fat tissues and the perception of abnormal flavours and odours in the meat.
skin the outer covering and largest organ of the body. It serves to protect the internal organs and tissues from physical damage and microbial contamination. The skin of cattle (hide) and of sheep (pelt) is normally removed on the slaughterline. The skin of pigs (rind) is not normally removed. The value of the skin of cattle or sheep to the tanning industry is an important contribution to the economics of animal production.
slaughter the killing of animals for the preparation of meat for human consumption normally carried out at an abattoir. There are many methods legally employed within the EU to slaughter farm species, the use of which depends upon species, religious and welfare considerations.
slaughter weight the weight of the animal (liveweight) at slaughter.
slaughterhall the part of an abattoir in which the act of slaughtering of animals takes place. Also may be called the slaughter floor.
slaughterline production line (often semi-automated) along which the various processes involved in the slaughter and dressing, meat inspection, weighing and classification of carcases take place within the abattoir. The part of the slaughterline on which dressing takes place is often termed the dressing line.
smoking originated as a method of preserving cured meat, most commonly bacon and frankfurters by inhibiting microbial contamination, retarding fat oxidation and preserving muscle colour. Smoking also imparts a unique flavour to the product which is preferred by some consumers ensuring the continuation of this process in the advent of other methods of preservation. Traditionally the meat is cured then smoked in a smoke house or a kiln, using special woods to impart particular flavours.
sow a female porcine animal which has produced a litter of piglets.
splitting the division of a carcase into sides. This is now usually achieved by the use of a saw or automated cleaver. The use of a saw results in less splintered bone but more bone dust. For this reason many pig abattoirs use mechanical cleavers.
steer castrated bovine animal often referred to as a bullock.
sticking see exsanguination.
store generally refers to weaned animals requiring further feeding before slaughter. This term can be used with reference to any species but is more commonly used for cattle and sheep (e.g. store lambs).
stress situations that increase the amount of unaccustomed physical or emotional activity of an animal cause stress. There are basically three types of stress to which meat animals are exposed. These are: (i) social, e.g. the mixing of groups of animals leading to a loss of hierarchy (pecking order) which can lead to bullying; (ii) environmental, e.g. extremes of temperature; and (iii) physical which includes stresses imposed during the movement, transportation and slaughter of animals. In preparation for a “fight or flight” response, stress triggers the release of hormones such as adrenaline into the blood stream which stimulates the metabolism of muscles and increases susceptibility of an animal to developing meat quality problems.
stunning refers to methods used to render an animal insensible to pain, causing unconsciousness, at slaughter. In pigs, this is generally carried out by applying electrical current through the brain. In cattle, a captive bolt pistol is usually used to stun the animal. Sheep can be stunned using either of these two methods. Another method of stunning pigs is the use of carbon dioxide anaesthesia (see CO2 stunning).
subcutaneous means beneath the layers of skin (or rind). Most commonly used to describe backfat (subcutaneous fat) or the position of an injection or infusion.
suckler a young animal that is drawing milk from its dam, i.e. suckler calf or lamb. May also be used to refer to a suckler cow.
suckler cow a cow that is nursing a calf. The milk produced during lactation is used solely to feed a calf (single suckling) or several calves (multiple suckling). These animals are normally beef breeds, or females resulting from beef bulls crossed onto dairy cows, producing calves for meat production.
suckling pig an un-weaned, milk-fed piglet. The meat from such animals is a delicacy in many parts of the world, the carcases are cooked whole. It is not common practice to slaughter such young pigs in the UK.
swine pertaining to or emanating from pig.
taint generally refers to some form of contamination of meat by uncharacteristic odours and/or flavours. Such taints can be caused by substances contained within certain raw material foodstuffs, microbial contamination, or oxidation of fats present in the meat. Taints can also be caused by the absorption of undesirable odours and flavours from atmospheric contaminants. Unpleasant odours and flavours due to sex related compounds in entire male animals (especially pigs, see boar taint) are also referred to as taint, even though they are naturally present and therefore cannot be considered as contamination.
tallow hard animal fat chiefly from cattle or sheep used to make soap, candles, lubricants and many other products. It is high in calories and can be used as an energy source in animal feeds. Tallow is produced by rendering.
taste is an important constituent of the evaluation of the eating quality of meat. There are four “basic” tastes: sweet, sour, salt and bitter.
tenderisation is an improvement in tenderness of meat. This occurs naturally due to proteolysis during the ageing process, or artificially. Artificial tenderisation can be carried out by stretching or pounding the meat, electrical stimulation of the carcase, blade tenderisation, or by the application of a commercial enzyme preparation to the meat such as papain.
tenderness is one of the major and most variable eating quality (organoleptic) attributes of meat. The causes of tenderness variation are thought to involve elements of muscle structure (size and types of muscle fibres, connective tissue distribution), the nature and extent of post-mortem biochemical changes (shortening and ageing) and cooking procedures.
tendon a band of strong white fibrous connective tissue that connects a muscle to a bone. Tendons consist predominantly of collagen.
terminal sire a sire used to produce the slaughter generation when crossed with a female of another breed, line or strain. The terminal sire used for producing a slaughter generation should confer the traits of high growth rates, good feed conversion efficiency and good carcase quality to his progeny.
texture the combination of physical properties perceived by senses of nerve endings, thus touch (including mouth feel), sight and hearing. The meat quality attributes of appearance and eating quality (particularly tenderness and juiciness) therefore contribute towards the assessment of texture.
tumbling refers to the procedure of massaging pieces of meat against one another in a rotating drum. It is used to aid distribution of curing salts. It also can be used to draw out salt soluble proteins to the meat surface for use in binding cuts to make re-formed meat products.
unsaturated see fatty acid.
vacuum packaging is the storage of meat in the absence of oxygen or any other gas. This is an effective method of extending the shelf life of uncooked meats. Inhibiting access of oxygen to the meat reduces oxidation and therefore stops the transformation of red oxymyoglobin to a brown metmyoglobin, thus maintaining muscle colour. This anaerobic atmosphere also inhibits the accumulation of many harmful micro-organisms thus reducing bacterial deterioration of the meat.
veal the meat from calves usually slaughtered between 16 to 26 weeks of age, depending on breed, sex and feeding regime. Veal production systems used in the UK allow groups of calves freedom of movement with ad libitum access to a roughage and milk. This does however, lead to lower feed efficiencies (due to rumen development) and produces a darker coloured meat. The increased “pinkness” of the meat, results from the higher intake of iron, which increases muscle haem content. White veal produced on the Continent is obtained from a calf fed a virtually iron-free diet of mainly milk. White veal production systems are, in essence, producing an anaemic animal.
water (moisture) content the amount of water present in meat. This is normally expressed as either a percentage by weight or as g/kg of tissue. Moisture content of lean muscle tissue is normally around 70-75 % depending upon species, amount of intramuscular fat present, muscle type and age and nutritional state of the animal.
welfare see animal welfare.
WTO World Trade Organisation www.wto.org
