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1000 mg is consumed daily for at least 3 months. This

intake is unlikely under normal circumstances and for

most individuals the risk of gallstone formation can

be considered to be independent of dietary cholesterol

intake.

0019 Unsaturated fat There is evidence to suggest that

subjects consuming a diet low in saturated fat

and cholesterol but high in unsaturated fat may

be more susceptible to gallstones. One possible mech-

anism is that such diets encourage the mobilization of

cholesterol from plasma and tissue and, therefore, its

excretion in greater quantities in the bile.

0020 Fasting There is diurnal variation in the compos-

ition of bile, with cholesterol levels being higher

in bile produced at night. This is more likely to

influence stone formation if the more lithogenic

nocturnal bile is retained in the gallbladder for long

periods. As food intake stimulates gallbladder

contraction, long intervals of 8–15 h between meals

will result in bile stagnation and the increased risk of

stone formation.

0021 Alcohol A moderate intake of alcohol may protect

against gallstone formation.

0022 Caffeine There is limited epidemiological evidence

to suggest that consuming four or more cups of regu-

lar coffee per day may help prevent symptomatic

gallstone disease in men. This effect has not been

observed with decaffeinated coffee.

Clinical Factors

0023 Patients with certain medical conditions are more

susceptible to gallstone formation. Approximately

30% of individuals with cirrhosis of the liver have

gallstones, predominantly composed of pigment. Re-

sections of the ileum also increase the risk of stone

formation as bile acids are not reabsorbed, resulting

in a reduced total bile salt pool.

0024 Cholestyramine and clofibrate, prescribed to lower

plasma lipid concentrations, may also increase

the risk of gallstone formation. Cholestyramine acts

by binding bile acids, preventing reabsorption,

while clofibrate increases biliary cholesterol excretion.

0025 Long-term parenteral nutrition may result in stone

formation in adults and children because in the ab-

sence of oral intake there is reduced stimulus for

gallbladder, thus stagnant, lithogenic bile is retained.

Treatment

0026 Once gallstones have formed they may remain

asymptomatic or cause cholecystitis, discussed

below. If an individual has no symptoms, and the

stones are diagnosed incidentally, then no treatment

may be required. Approximately 15% of asymptom-

atic stone carriers will develop symptoms during a

follow-up of 10–15 years, and a policy of whether

or not to treat them while they remain asymptomatic

varies from center to center.

Dietary Management

0027It would be prudent for obese individuals with gall-

stones to lose weight with a moderate calorie restric-

tion. For those within the ideal weight range, a

healthy diet along the lines recommended by the

Committee on Medical Aspects of Food Policy

would be suitable. This advised that fat in the diet

should provide a maximum of 35% of food energy

and that fiber intake should be increased. In the UK in

1997 the average diet provided 39% of total calories

from fat, and only 12 g of fiber (measured as non-

starch polysaccharide) per day. A reduction in fat

towards a maximum of 35% energy and an increase

in fiber intake to approximately 18 g day

1

would be

suitable for individuals with gallstones, as well as for

the healthy adult population. There is no evidence

that a lower fat intake would be beneficial for indi-

viduals with gallstones.

0028A regular intake of three meals a day, including

breakfast, which will insure periodic emptying of

the gallbladder, may also be helpful.

Cholecystitis

0029Once gallstones have formed they may not give rise to

symptoms, unless they move into the neck of the

gallbladder, cystic duct, or common bile duct. Here

they can obstruct the release of bile, so that when the

gallbladder contracts the pressure rises, causing pain.

In addition, the retained bile acts as a chemical

irritant on the mucosal wall and makes the area

susceptible to bacterial infection. Bile salts may be

deconjugated by bacteria to produce further irritation

and injury to the mucosa. In severe cases the pressure

rise compresses small blood vessels, producing infarc-

tion and gangrene.

0030Cholecystitis is classified as acute or chronic. An

acute attack can develop where there is already under-

lying chronic disease. It may also occur where there

has been no previous history of gallbladder disease.

Acute Cholecystitis

0031This is characterized by severe pain in the right upper

abdomen or epigastrium, lasting up to an hour with-

out relief. Nausea may be present and the patient may

become pyrexial. If a gallstone has escaped from the

gallbladder and lodges in the common bile duct, the

2848 GALLBLADDER

patient may become jaundiced. Eighty-five percent of

patients recover spontaneously from acute cholecys-

titis. However, further attacks are common, although

there may be long intervals between them. Compli-

cations of acute cholecystitis include gangrenous

cholecystitis, liver abscess, peritonitis, and the forma-

tion of fistulae to the bowel.

Treatment

0032 The patient is treated with antibiotics to control the

infection, usually caused by gut organisms such as

Escherichia coli, Streptococcus faecalis or Klebsiella

sp. Analgesia and intravenous fluids are also required

in the acute phase as the patient may be severely ill

and may be unable to take oral fluid.

0033 After the acute attack has subsided, surgical re-

moval of the gallbladder (cholecystectomy) is recom-

mended to prevent further episodes of pain or

progression to the complications of empyema. The

mortality of cholecystectomy carried out within the

first 3 days of acute cholecystitis is 0.5%.

Dietary Management

0034 Traditionally, when the severe pain of cholecystitis

has subsided and the patient is able to eat, a light,

usually low-fat diet is recommended. However, an

evidence-based reevaluation of this practice is re-

quired. Dietary fat is a potent stimulator of CCK secre-

tion which causesgallbladder contraction andpossibly

exacerbates pain. However, CCK is also secreted in

response to dietary protein, mixed meals, elemental

diets, and both regular and decaffeinated coffee. In

addition, the gallbladder will contract in response to

sham feeding without any gastric, duodenal, or jejunal

stimulation. This cephalic phase of gallbladder con-

traction is independent of CCK secretion and possibly

mediated through a cholinergic mechanism. If a gall-

bladder is able to contract in the absence of ingested

food, there is little evidence to support the avoidance of

dietary fat. A study of gallbladder dynamics in patients

with gallstones measured the effect of test meals con-

taining varying amounts of fat on the postprandial

gallbladder volume. The response was shown to be

independent of the fat content in the meals. Most

studies of gallbladder contraction have been carried

out on subjects with functioning gallbladders but it is

unlikely that the response to food stimulation would

be greater after acute cholecystitis, if it is changed at

all. In the absence of any evidence to the contrary, it

would be justified to advise patients to try to eat a

normal healthy diet after acute cholecystitis. There is

no justification for imposing a virtually fat-free

regime in an attempt to avoid pain. If certain foods

cause distress to an individual it is reasonable to avoid

them. This should not cause nutritional problems if

the diet is varied and balanced. Reassurance about

eating in general may be needed, as many people are

afraid to eat after the severe pain they have experi-

enced. If they remain unwell, supplementary drinks

or nutritious ‘between-meal snacks’ would help to

insure that their total nutrient intake is adequate.

Chronic Cholecystitis

0035This may arise with or without a previously docu-

mented attack of acute cholecystitis. The symptoms

may be vague, with epigastric discomfort, particu-

larly after eating, and distension of the abdomen.

There may be nausea and flatulence which is often

relieved by belching or taking antacids. Diagnosis

may be difficult because of ill-defined symptoms.

Moreover, dyspepsia may be associated with other

gastrointestinal diseases. Ultrasound is used to diag-

nose gallstones and gallbladder disease. Endoscopy

may be necessary to rule out peptic ulceration, hiatus

hernia, or gastritis.

Treatment

0036Elective cholecystectomy is recommended if the pa-

tient suffers repeated attacks of pain. The mortality is

0.1% in patients less than 50 years old and 0.5% if

the patient is over 50 years old.

0037If patients are unable to undergo surgery because of

age, poor general health, or other conditions, they may

be treated medically. Dissolution of gallstones using

oral bile salts may be attempted if the cystic duct is

patent and the stones are radiolucent (i.e., predomin-

antly cholesterol-containing). Patients must be compli-

ant and prepared to follow the treatment for at least 2

years. The aim of dissolution therapy is to expand the

total bile salt pool and increase the concentration of

bile salts in the bile by giving oral cheno- or urso-

deoxycholic acid. Successful dissolution occurs in

14–30% of patients after 2 years of treatment, but

side-effects include diarrhea and increased plasma

cholesterol. Multiple stones may also be dissolved

by topically applying methyl tertbutyl ether. Small

numbers of medium-sized stones may be fragmented

using extracorporeal shock-wave lithotripsy. However,

stone recurrence within 5 years is a problem in approxi-

mately 50% of patients undergoing nonsurgical treat-

ment. These results compare unfavorably with

cholecystectomy, but should be considered in patients

for whom surgery is too great a risk.

Dietary Management

0038As with asymptomatic gallstones, the first priority for

obese patients is to lose weight to within the ideal

range for their height. As well as ultimately reducing

the cholesterol level in bile, gentle weight reduction

GALLBLADDER 2849

will make potential surgery easier and less hazardous.

When normal weight is attained, a healthy diet should

be continued, in line with recommendations for the

general population: a maximum of 35% of energy

from fat and 18 g fiber day

1

0039 Patients with chronic cholecystitis frequently de-

scribe dyspepsia associated with certain foods but

there is little evidence to incriminate any particular

cause. When subjects describing fat intolerance were

challenged with fat without their knowledge, only

8% suffered dyspepsia. Symptoms therefore appear

to relate more to preconceived ideas about dietary fat

than the fat itself. If particular foods are thought to

provoke gastrointestinal symptoms the individual

may wish to avoid them, but otherwise a liberal but

healthy diet should be recommended.

After Cholecystectomy

0040 Although up to one-third of patients have symptoms

after surgical removal of the gallbladder, this is prob-

ably because they did not have cholecystitis in the first

place: 95% of patients found to have gallstones at

surgery suffer no further symptoms afterwards. With

the removal of the gallbladder and its function as a bile

reservoir there is a redistribution of the bile acid pool.

Increased bile acid cycling in the enterohepatic circu-

lation results in greater cholesterol solubility. After

surgery, patients should eat a normal healthy diet.

Obstructive Jaundice

0041 Obstructive jaundice may be caused by a gallstone

lodged in the common bile duct, carcinoma of the

pancreas, bile duct or ampulla and, rarely, benign

biliary strictures. A patient presenting with obstruct-

ive jaundice will need medical investigation to deter-

mine the cause of the obstruction and the treatment

required. Ultrasound scanning and cholangiography

are needed.

0042 Typically, the patient with a common duct stone

has epigastric pain, jaundice, dark urine, and fever.

Malignant bile duct obstruction is usually painless

and without fever. Once the cause is confirmed,

medical or surgical treatment is selected.

Dietary Management

0043 Dietary advice should include both basic nutritional

support in patients who may be ill, frail and cachexic,

and symptomatic help for those with fat intolerance.

Depending on the degree of obstruction, little or no

bile may enter the duodenum, so that dietary fat may

be inadequately emulsified, resulting in fat malabsorp-

tion (steatorrhea). If the obstruction is at the lower end

of the biliary tract, e.g., at the ampulla of Vater, the

pancreatic duct may also be obstructed, and the lack of

pancreatic lipase will exacerbate steatorrhea. If stea-

torrhea is present, dietary fat should be reduced to

levels tolerated by the individual and, if appropriate,

pancreatic enzyme supplements prescribed. The cal-

orie deficit from the reduced fat must be made up with

an increased carbohydrate and protein intake.

Medium-chain triglycerides may be useful as an add-

itional source of calories as these are partially water-

miscible and do not require bile for emulsification.

When steatorrhea is present, fat-soluble vitamins

should be given by intramuscular injection as enteral

absorption is unreliable. If a patient does not have

steatorrhea there is no benefit from restricting dietary

fat, and such a diet should not be recommended pro-

phylactically because of its negative impact on palat-

ability and energy intake.

0044If obstructive jaundice is accompanied by recurrent

infections (cholangitis) and the situation cannot be

improved by surgical or medical treatment, for example

in primary sclerosing cholangitis, it is essential that

adequate nutritional support is given since weight loss

and cachexia are commonly seen. Palatable supplements

and plenty of encouragement to eat may be needed to

help a patient achieve an acceptable nutritional intake

and prevent further malnutrition.

Role of Low-fat Diets in Gallbladder

Disease

0045It is a commonly held misconception among both

the general public and some professionals that dis-

orders of the gallbladder should automatically be

treated with a diet restricted in fat. If this is taken to

extremes and continued for long periods (over 3

weeks), several problems may arise. A very-low-fat

diet is unpalatable and may require a large bulk of

food to be eaten in order to provide sufficient cal-

ories. If the low-fat diet results in an inadequate

energy intake, undesirable weight loss may occur.

Clinical deficiencies of the fat-soluble vitamins, A,

D, E, and K, may also eventually arise if the dietary

intake is deficient and supplements are not given. An

adequate intake of essential fatty acids, linoleic and

linolenic, is unlikely to cause the characteristic skin

changes associated with deficiency unless a severely

fat-restricted diet is followed for several months but,

even for shorter periods, such a diet will result in a

suboptimal and unacceptable nutritional state.

0046There is insufficient evidence to support the wide-

spread use of fat restriction in the avoidance of pain in

gallbladder disease. However, when pain is associated

with fat intake in an individual, a reduced fat intake

may help, provided that the total diet remains

adequate.

2850 GALLBLADDER

0047 Fat restriction may be beneficial for some patients

with obstructive jaundice accompanied by diarrhea. In

this case, it should be followed only on medical advice

and with the guidance of a state-registered dietitian.

See also: Caffeine; Cholesterol: Factors Determining

Blood Cholesterol Levels; Dietary Fiber: Properties and

Sources; Fats: Requirements; Obesity: Etiology and

Diagnosis; Vegetarian Diets

Further Reading

Andersen T (1992) Liver and gallbladder disease before and

after very-low calorie diets. American Journal of Clinical

Nutrition 56(S1): 235S–239S.

Corazziari E, Shaffer EA, Hogan WJ, Sherman S and Toouli

J (1999) Functional disorders of the biliary tract and

pancreas. Gut 45(S2): 48–54.

Department of Health (1991) Dietary Reference Values for

Food Energy and Nutrients for the United Kingdom.

Report on Health and Social Subjects 41. Committee

on Medical Aspects of Food Policy. London: Depart-

ment of Health.

Hopman WPM, Jansen JBMJ, Rosenbausch G and Lamers

CBHW (1987) Cephalic stimulation of gall bladder con-

tractions in humans. Digestion 38: 197–203.

Madden A (1992) The role of low fat diets in the manage-

ment of gall-bladder disease. Journal of Human Nutri-

tion and Dietetics 5: 267–273.

Mogadam M, Albarelli J, Ahmed SW, Grogan EJ and Mas-

catello VJ (1984) Gallbladder dynamics in response to

various meals: is dietary fat restriction necessary in the

management of gallstones? American Journal of Gastro-

enterology 79: 745–747.

Niebergall-Roth E, Teyssen S and Singer MV (1997)

Neurohormonal control of gallbladder motility. Scandi-

navian Journal of Gastroenterology 32: 737–750.

Portincasa P, van de Meeberg P, van Erpecum KJ, Palas-

ciano G and VanBerge-Henegouwen GP (1997) An

update on the pathogenesis and treatment of cholesterol

gallstones. Scandinavian Journal of Gastroenterology

Supplement 223: 60–69.

Sherlock S and Dooley J (1996) Diseases of the Liver and

Biliary System, 10th edn. Oxford: Blackwell Science.

Strasberg SM (1998) The pathogenesis of cholesterol gall-

stones: a review. Journal of Gastrointestinal Surgery 2:

109–125.

Tseng M, Everhart JE and Sandler RS (1999) Dietary intake

and gallbladder disease: a review. Public Health Nutri-

tion 2: 161–172.

Utter A and Goss F (1997) Exercise and gallbladder func-

tion. Sports Medicine 23: 18–27.

GAME

Contents

Birds

Mammals

Birds

P J Hudson, University of Stirling, Stirling, UK

This article is reproduced from Encyclopaedia of Food Science,

Introduction

0001 Game bird production and harvesting are undertaken

principally for the financial and social benefits that

accrue from shoot-letting rather than as a source of

nutrition. However, since the regulations that relate

to private property rights vary between countries, so

the relative importance of game birds as a food source

and as an important form of financial income varies

around the world.

Game Bird Production and Revenue

0002Within the British Isles, the laws relating to hunting

season are liberal and restrictions on the level of the

harvest are left to the individual who owns the rights

to take game from the property, usually the land-

owner or, on common ground, the Lord of the

Manor. Since game production can result in a profit-

able harvest, the land-owner has an incentive to

manage the land in a manner sympathetic to game

production and, when possible, to rear and release

game birds to supplement wild birds. People with an

interest in shooting then pay for the privilege of

shooting the birds, usually on a daily basis, and the

dead birds remain the property of the land-owner.

0003The financial return from the letting of game shoot-

ing can provide a significant income to many British

GAME/Birds 2851

estates. Consider the financial aspects of grouse

shooting in Britain. The red grouse is a wild game

bird restricted to the heather moorlands of the British

Isles; numbers are not supplemented through rearing

or releasing but are increased through the care of the

heather habitat and the control of harmful predators

and parasites. The revenue generated from the letting

of grouse shooting depends on the type of shooting

undertaken. Driven shooting, where a group of 16

people drive the grouse to a line of 8–10 people

standing with guns, can only occur when August

grouse densities are sufficiently high and usually

only when they exceed 60 birds per square kilometer.

During 1991, driven grouse shooting was let at £70

per brace (one brace ¼ two birds) and daily grouse

bags of up to 500 and 650 brace per day were

recorded. However, this level of harvesting is unusual

and a productive day’s driven grouse shooting is nor-

mally in the region of 100 brace per day. Even so, a

day’s let grouse shooting which generates £7000 gross

per day forms an important source of financial return

for upland estates which would otherwise have to

depend on poor returns from sheep farming or com-

mercial afforestation.

0004 The sale of the game from these commercial shoots is

an insignificant return. During 1991, old grouse were

selling at £1 per brace and young grouse at £3.50 per

brace, which amounted to approximately 5% of gross

margin. Traditionally, each sportsman receives a brace

of birds at the end of a day’sshootingandtheremainder

are sold to game dealers who export the meat as a

delicacy to continental Europe.

0005 The revenue gathered from game shooting can be

significant; within Scotland, the direct and indirect

revenue of grouse shooting alone in 1989 generated

a total of £10.3 million to the Scottish gross domestic

product and created the equivalent of 2323 full-time

jobs. These jobs were often in remote rural areas in

which alternative opportunities were limited.

0006 The financial returns from birds reared and

released provide a much lower net return since the

costs of rearing and subsequently feeding are high. In

1991, pheasant rearing costs almost equalled the £15

per bird return at which pheasant shooting is let.

Once again the carcass value is low, at only £1 per

bird or 7% of the gross margin.

0007 In contrast to the British system, North American

hunters have free access to vast areas of land and the

game that it may contain and generally must purchase

a license to take a limited number of game. Conse-

quently the shooting season is shorter, but more

intense, with a limited annual bag for each quarry

species. Financially the system is designed so that the

money generated from licenses and from taxes on

guns and sporting equipment is used to finance the

state Fish and Wildlife Services. Unlike the British

intensive system of game production, the American

system provides an incentive for a larger proportion

of the population to be involved in the sport and have

access to the game as a source of food.

Harvesting Strategies

0008The objective of most harvesting strategies is to pro-

duce the maximum long-term yield of game from a

population (known as the maximum sustainable yield

or MSY), be it for economic revenue, quantity of food

produced, or even the esthetic benefits arising from

the conservation of the game bird resource. The size

of the MSY that can be obtained from a population

can be estimated through mathematical models using

a number of approaches.

0009The simplest is to consider a population that in-

creases according to a logistic growth curve where the

per capita rate of increase falls linearly as the popula-

tion rises; when this reaches zero the population has

reached its carrying capacity. Harvesting this popula-

tion will result in the size of the population falling to a

level where the harvesting rate is equal to the popula-

tion growth rate. The MSY is reached when the

harvest rate equals the maximum growth rate of

the population, and for the logistic model this is

when the density is at half the carrying capacity.

Higher harvesting rates will result in the final

extinction of the population, whereas lower harvest-

ing rates allow the population to rise until harvesting

rate equals the growth rate of the population.

0010For any regulated population it is important to

realize that any sustainable yield, including the

MSY, lies at a level below the carrying capacity of

the environment. This point is rarely appreciated by

managers of wild animal populations or even by

many biologists who are frequently concerned with

keepering a breeding population as high as possible

in the misplaced belief that this will increase the

quantity of the resource available for harvesting.

MSYs have been estimated for a number of game

bird populations; for example, MSY for bobwhite

quail is 55% of the autumn population, which re-

duces the size of the population to 72% of the unhar-

vested state. For gray partridges the MSY is about

37%, mallard 29%, and pheasants 20% of the female

population. For other species MSYs may not be easily

calculated since numbers may fluctuate greatly and

the optimal solution may depend on whether the

population is increasing or decreasing.

0011The release of reared birds provides a supplement

to the wild population but may result in overhar-

vesting of the wild population and in the long term

the loss of a wild breeding population. For example,

2852 GAME/Birds

in Italy, 275 000 gray partridges are reared and re-

leased annually and approximately 65% are subse-

quently shot. Such a level of harvesting is far too high

for the wild population to be sustained and yet this is

not apparent to the hunters, since the rearing has

maintained the size of the harvest. The released

birds have a poor survival rate and rarely breed

well, so there is insufficient recruitment into the wild

population.

Environmental Benefits of Game Bird

Production

0012 One of the major benefits of wild game bird shooting

are the indirect benefits of game management to the

environment. Game management has frequently

resulted in the amelioration of the harsher effects of

agriculture and commercial afforestation on the

environment.

0013 Inevitably farming has produced major ecological

changes to the environment, particularly in recent

years through the mechanization of farming methods

and the application of pesticides, fertilizers, and other

chemicals which may have both direct effects in redu-

cing nontarget species and indirect effects through the

loss of food species utilized by other organisms. Per-

haps the most obvious effect has been the dramatic

decline in biodiversity associated with the cereal eco-

system. The effects on game birds (Table 1) have been

dramatic but have also included a large number of

other species such as the almost total demise of

the once-abundant corn crake. Even in the uplands

of Britain one of the most important impacts has been

the overutilization of the seminatural habitat by

domestic stock, which has directly destroyed habitats

and in so doing reduced the abundance of the inver-

tebrate food taken by immature game birds (Table 1).

0014 The simple answer to reducing environmental

damage and problems of agricultural intensification is

to change the direction of the system towards one of

extensification. Reduction of the impact of pesticides

on cereal fields without significantly reducing the yield

can be achieved through the use of conservation head-

lands, where limited application of pesticides results in

the maintenance of beneficial broad-leaved weeds and

the invertebrate fauna associated with them.

0015Large areas of the British countryside are planted

with woodland specifically with the objective of pro-

ducing pheasants. The maintenance of these wood-

lands, production of rides, and other management

activities have proved highly beneficial to song

birds, butterflies, and other animals. Similarly,

heather moorlands are a habitat of international im-

portance, a large proportion of which is centered in

the uplands of Britain and maintained principally

through the management activities of estates inter-

ested in grouse shooting.

Wise Use of Gamebird Resources

0016The concept of wise use of renewable resources has a

number of interpretations and has yet to be defined in

detail. The principle is that the management of the

resource, game birds in this case, encourages harvesting

at a sustainable level which provides benefits to the

conservation of the species harvested and has add-

itional benefits to human society and conservation of

other species without exploitation.

0017One example of this wise use has been in the pro-

duction of red-legged partridge shooting in the

Ciudad Real province of Spain. After the revolution,

few partridges existed, but the population was

subsequently increased to a level where the popula-

tion could be harvested through careful management

and the cooperation of the local farmers. A harvest is

produced which is of value to the whole rural com-

munity and provides the farmers with an economic

interest in the care and habitat protection of the birds.

Two brothers acquired shooting rights over the

ground owned by more than 2000 individuals and

produced a commercial partridge shoot bringing in

nearly $3 million annually. Half of this money is

tbl0001 Table 1 Population size, harvest, and management recommendations for British game bird species

Species Number prior to harvest Harvest Status Problem facingpopulation

Red grouse 1 500 000 30% Stable after decline Overgrazing, predation, and disease

Ptarmigan 35 000 5% Stable after decline Overgrazing and predation

Black grouse 40 000 5% Stable after decline Overgrazing and predation

Capercaillie 2 500 0% Declining Overgrazing and predation

Red-legged partridge 1 500 000 30% Decline after increase Release of chukar partridges

Grey partridge 1 250 000 15% Declining steeply Predation and intensification of cereals

Pheasant 20 000 000 50% Slight decline Predation and intensification of cereals

Woodcock 1 000 000 10% Stable after increase

Common snipe 720 000 5% Stable after decline Drainage

Woodpigeon 13 000 000 18% Increase after decline

GAME/Birds 2853

distributed locally each year by paying a set amount

per hectare to the local farmers, an amount for each

partridge clutch hatched on the ground, and compen-

sation for any damage. Local taxes are alsopaid

which have resulted in local community benefits

such as street lighting. The wise use in the develop-

ment of partridge shooting has had clear economic

benefits to the local community and, with a financial

interest in each brood produced, encourages farmers

to create habitat and reduce intensification of

marginal agricultural land.

Scent, Taste, and the Significance of

Hanging Game

0018 Game birds have a characteristic taste which can be

accentuated through the effects of hanging the dead

birds for a period prior to eating. This is a habit

developed in colder climates where the daily tempera-

tures during the winter hunting season are usually less

than 10



C. At higher temperatures, and particularly

in damp conditions, hanging game can lead to bacter-

ial development and the rotting of game even when

care is taken to avoid fly strike.

0019 In Britain, the technique is to examine shot birds,

often plucking the lower abdomen to determine that

the guts have not been badly punctured. The birds are

then hung in a cool game larder with air circulating,

away from direct sunlight and so that the birds are

not touching each other. The time the birds are left to

hang depends on the age of the bird, size of the species,

and the weather conditions. In August, young grouse

are usually eaten immediately, whereas older birds are

left for 2–4 days. Young partridges shot in September

are also only hung for a short time so as not to lose the

delicate taste of young birds. Young pheasants in Oc-

tober are usually hung for about 3 days, although by

January when the temperature is cool the birds can be

hung for 14–18 days. Usually birds are examined

regularly until the skin below the breast bone turns

bluish and produces a slight smell.

0020One of the characteristic of game birds is the strong

scent and taste they emit. The scent is frequently so

strong that a pointing dog can locate a bird 50 m

downwind and on occasions even further, up to

200 m. Occasionally the scent can be so strong a

human observer can smell a grouse at 10 m. One inter-

esting characteristic for most game birds is that scent

emission falls and almost ceases once incubation com-

mences, so that trained pointing dogs have problems

locating an incubating hen from distances greater than

0.5 m. This change in scent emission coincides with

the birds ceasing to produce cecal feces, a brown

glutinous feces produced daily from the ceca of the

bird which contrasts with the more familiar fibrous

feces. It seems likely that much of the scent and taste of

the game birds may derive from the birds’ ceca.

0021Most red grouse carry a burden of the cecal nema-

tode Trichostrongylus tenuis, which burrows into

the cecal wall and causes internal bleeding. Heavily

parasitized birds frequently have a stronger taste and

may emit more scent. This was demonstrated through

a simple experiment. Trained pointing dogs and

human observers were used to locate two groups of

incubating females, one which had been treated with

an anthelmintic to remove the parasitic nematode and

a second control group that had received water. Ob-

servers and dogs searched for nests, the dogs search-

ing by scent and the human observers by sight. The

human observers found the treated birds in the pro-

portions expected but the dogs located relatively few

of the treated birds, presumably because they emitted

less scent since they carried few parasites. The sugges-

tion is that scent and taste of grouse may be deter-

mined by the birds’ ceca.

0022The role of the ceca in digestion is not clear. They

were originally thought to function primarily as a

suitable environment for the fermentation of plant

fiber, but such a hypothesis has been rejected. Ceca

are now thought to separate soluble and suspended

particulate food components from insoluble material.

The adaptive significance is to maximize the rate of

tbl0002 Table 2 Nutrient composition (g per 100 g) of game birds; roasted meat compared with roasted chicken

Water Protein Fat Total N Fattyacids

Saturated Mono-unsaturated Poly-unsaturated

Chicken 68.4 24.8 5.4 3.97 1.6 2.5 1.0

Grouse 61.6 31.3 5.3 5.00 1.2 0.7 3.1

Partridge 54.5 36.7 7.2 5.87 1.9 3.3 1.7

Pheasant 56.9 32.2 9.3 5.15 3.1 4.6 1.1

Pigeon 57.2 27.8 13.2 4.44 N

N ¼ no data available.

Data abstracted from Holland B, Welch AA, Unwin ID et al. (eds) (1991) McCance and Widdowson’s Composition of Foods, 5th edn. Cambridge: Royal Society

of Chemistry and Ministry of Agriculture, Fisheries and Food.

2854 GAME/Birds

Table 3 Micronutrient composition (per 100 g) of game birds; roasted meat compared with roasted chicken

Elements (mg) Vitamins

Na K Ca Mg P Fe Cu Zn Cl Mn Retinol

(mg)

Carotene

(mg)

Vitamin

D(mg)

Vitamin

E(mg)

Thiamin

(mg)

Riboflavin

(mg)

Niacin

(mg)

Tr y p t -

ophan

(mg)

Vitamin

(mg)

Vit amin

(mg)

Folate

(mg)

Panto-

thenate

(mg)

Biotin

(mg)

Vitamin

C(mg)

Chicken 81 310 9 24 210 0.8 0.12 1.5 87 0.03 Tr

Tr Tr 0.11 0.08 0.19 8.2 4.6 0.26 Tr 10 1.20 3 0

Grouse 96 470 30 41 340 7.6 0.10 1.5 130 0.06 N

N N N 0.19 0.80 7.0 5.8 0.64 0.9 37 N N 0

Partridge 100 410 46 36 310 7.7 N N 99 N N N N N N N N 6.9 N N N N N 0

Pheasant 100 410 49 35 310 8.4 0.10 1.3 110 0.02 N N N N 0.02 0.29 9.2 6.0 0.57 2.5 20 N N 0

Pigeon 110 410 16 34 400 19.4 0.33 1.7 99 0.05 N N N Tr 0.27 N 7.0 5.2 0.82 N 8 N N 0

Tr, trace; N, no data available.

Tryptophan values are divided by 60.

Data abstracted from Holland B, Welch AA, Unwin ID et al. (eds) (1991) McCance and Widdowson’s The Composition of Foods, 5th edn. Cambridge: Royal Society of Chemistry and Ministry of Agriculture, Fisheries and

Food.

fig0003

throughput for birds feeding on a high-fiber, low-

nutrition diet.

Nutrient Composition

0023 Compared with other forms of poultry, relatively little

information has been published for game birds. How-

ever, a comparison of the data available with com-

parable data for chicken shows that the nutrient

compositions are not dissimilar (Table 2). In general,

meat from game birds is somewhat richer in the sense

that it has a higher protein and fat content than chicken.

The increased fat content affects the texture of the meat

and also its stability on storage. No significant body of

data is available to compare the nutritional value of wild

birds with those bred in captivity.

0024 The limited information available on micronutrients

(minerals and vitamins) shown in Table 3 would also

suggest that there are no major differences between the

meats of game birds in this respect. (See Meat:Nutri-

tional Value.) Refer to individual nutrients.