Ducks and Geese Used in Foie Gras Production – Comprehensive Research

Foie gras (French for fatty liver) is made by enlarging the livers of ducks or geese through overfeeding. Traditionally a seasonal delicacy in Europe, it is produced on several continents today. Approximately 80 % of global foie gras comes from the European Union; China, the United States and Canada are secondary producers1. Within the EU, 20,657 tonnes of foie gras were produced in 2024, of which 19,809 tonnes were duck foie gras and 848 tonnes were goose foie gras2. This section synthesises biological, industrial, economic and legal information about the birds used for foie gras, without advancing advocacy.

Species or hybrid Domestication and key traits Geographical use & reasons for selection Legal or cultural notes Domestic duck (Anas platyrhynchos domesticus) Derived from the mallard. Mallards were domesticated around 4000 B.C. by Egyptians, Chinese and Europeans3. Domestic ducks are gregarious, have a rapid growth rate and respond well to overfeeding. Male ducks are larger and calmer than females, which makes them easier to handle; female ducks often have a superficial venous network on the liver making them less suitable for foie gras4. Today the mulard (see below) and Pekin or Landes strains dominate commercial foie gras production. They are used in France, Hungary, Spain, Canada, China and the U.S. because they tolerate confinement and have high feed‑conversion efficiency. The EU Scientific Committee on Animal Health and Welfare noted that by 1995 over 90 % of French foie gras came from ducks5. Domesticated ducks are not subject to special legal protection beyond general animal welfare law. Male‐only fattening is standard because only males meet minimum liver weights set by EU regulation (≥300 g)6. Muscovy duck (Cairina moschata) Indigenous to Central and South America. Muscovies are genetically distinct and were domesticated by indigenous peoples before the Columbian exchange7. Adults are sexually dimorphic; males reach 4.5–5 kg and females 2.2–3 kg8. Muscovy males were historically force‑fed for foie gras, but pure Muscovy ducks are nervous and their livers lose fat; farmers therefore cross them with common ducks5. Muscovy ducks are reared mostly for meat and cross‑breeding. They are not widely used alone in foie gras production. Mulard (Mule duck) Sterile hybrid created by crossing a male Muscovy with a female domestic duck (often Pekin). Mulard ducks combine the Muscovy’s large frame with the domestic duck’s calmer temperament and feed efficiency5. Mulards are now the principal species for foie gras. They are used in France, Hungary, Spain, Bulgaria, the U.S. and Canada. Their sterility means hatcheries must constantly produce hybrid eggs, giving integrators control over genetics. Because the hybrids are sterile, farmers cannot hatch their own replacements; this dependence influences industry structure. Domestic goose (Anser anser domesticus) Descended from wild greylag (Anser anser) or swan geese (Anser cygnoides). As migratory birds, geese naturally accumulate large fat reserves; their livers can increase more than eight‑fold within two weeks and exceed 9 % of body weight. Geese are long lived and mate for life, making them valuable to small farms. Geese were the original foie gras source in France and central Europe. Today geese account for less than 10 % of world foie gras5 but remain important in Hungary, Bulgaria and eastern France. Landes and Toulouse geese are favoured for their docile temperament and ability to produce livers weighing 1 kg9. EU regulation requires goose livers to weigh at least 400 g to be labelled “foie gras”6. Some countries (e.g., France’s Alsace, Hungary) culturally value goose foie gras for its milder flavour and larger lobes.

The shift from geese to ducks was driven by economics and biology. Mulard ducks grow faster, convert feed more efficiently and require a shorter force‑feeding period (10–12 days) compared with geese (15–21 days)10. They are calmer and easier to handle, reducing labour costs. Ducks can also be used for confit and other meat products after liver removal, improving profitability. The EU report noted that pure Muscovy ducks were nervous and tended to lose fat, making cross‑breeding with domestic ducks essential5. By 1995 more than 94 % of French foie gras came from ducks5. Today ducks account for roughly 95 % of EU production (19 809 tonnes vs. 848 tonnes goose in 20242).

Migratory ducks and geese accumulate fat before migration. Domestic geese retain this ability; when overfed, their livers can increase eight‑fold and reach more than 1 kg. Landes geese overfed for 3–4 weeks produce livers weighing 1 000–1 200 g with fat content exceeding 50 % and rarely show pathological signs9. Mule ducks show similar physiological adaptation: their livers enlarge (300–500 g), storing triacylglycerols. Overfeeding triggers hepatic steatosis by increasing lipogenesis and reducing lipid export. Gene‐expression studies in geese identify candidate genes (e.g., ARAP2, GABRE, LCORL) associated with fatty liver weight. These genes modulate lipid metabolism and protection against negative effects.

Ducks and geese possess an elastic oesophagus that allows swallowing large boluses, a thick muscular proventriculus and a liver adapted to high lipid synthesis11. During overfeeding, starch from maize is converted to glucose and then fatty acids; the liver becomes the main site of lipogenesis. Ducks usually undergo force‑feeding twice daily for 12–15 days, while geese are fed three times daily for 15–21 days10. Ducks typically reach liver weights of 300–600 g; geese exceed 400 g6. Veterinary research notes that male ducks exhibit a calmer disposition and have larger livers than females, explaining the male‑only production system4.

Liver size and texture: Goose livers are larger (up to 1 kg) and yield a smoother, milder flavour; duck livers are smaller (300–600 g) with a more pronounced taste. Larger goose lobes allow for better‑shaped slices12. Disease susceptibility: Both species are susceptible to hepatic rupture, bacterial infections and metabolic disorders during overfeeding. Mule ducks may show higher fat accumulation in peripheral tissues, while geese exhibit a more physiological adaptation with limited inflammation9. Mortality and morbidity: Mortality during the force‑feeding phase exceeds 3 % in ducks and 4 % in geese—10–20 times higher than in non‑force‑fed birds13. Overfeeding can lead to respiratory difficulties, bone weakness and gait problems. Feed conversion: Ducks convert feed to liver tissue more efficiently than geese, which helps explain their dominance. Geese require longer feeding and more labour.

Foie gras production involves three phases: rearing, pre‑fattening, and force‑feeding (gavage). Practices vary by country, but core steps include: Hatchery and genetic selection: Fertile eggs are produced by crossing Muscovy males with domestic ducks to obtain sterile mulard ducklings or by breeding Landes and Toulouse geese. Hatcheries maintain parent flocks and select for growth rate, feed efficiency and liver yield. Female mulards are generally used for meat because their venous liver network makes them unsuitable for foie gras4. Brooding and grow‑out (10–12 weeks for ducks, 12–15 weeks for geese): Birds are reared in small flocks with outdoor access until maturity. Diets start with high‑protein feed and gradually shift to a high‑starch mixture (maize, wheat, soybean meal) during the pre‑fattening phase14. Grass or roughage is often provided to dilate the oesophagus and train birds for gavage14. Force‑feeding/gavage: Overfeeding begins when ducks are 10–15 weeks old. Ducks are typically fed twice daily for 12 days; geese are fed three times daily for 15–21 days10. Feed consists mainly of boiled maize mixed with fat (sometimes with wheat, cornmeal or oats). Tubes or auger‑type devices deliver feed directly into the oesophagus, and birds may be housed in individual cages or small pens. According to Euro Foie Gras, only healthy adult birds are force‑fed and the liver returns to normal weight within a few days of ceasing gavage11. However, welfare assessments dispute this reversibility (see Section 5). Slaughter and liver extraction: Birds are slaughtered immediately after the overfeeding period to prevent regression of hepatic fat. Carcasses are processed into meat products, feathers and down. In some countries (e.g., Hungary, Bulgaria), on‑farm slaughter is common; elsewhere, birds are transported to abattoirs. National differences: France uses primarily mulard ducks; force‑feeding is usually done in individual pens. Hungary and Bulgaria rely more on geese and maintain small farms with semi‑automatic feeding. In China’s Linqu county, farmers raise Landes geese imported from France and process 5 million geese annually, producing over 5 000 tonnes of foie gras—about 20 % of global production15. The Chinese industry uses semi‑automatic feeding machines that adjust feeding amounts based on sensors, boosting efficiency16.

Shorter production cycle: Ducks reach slaughter age at 100 days, and the overfeeding period lasts 12 days10. Geese require 112 days and 15–21 days of gavage, increasing costs. Feed efficiency: Ducks convert feed to liver more efficiently, reducing input costs. Temperament: Male ducks are calmer and easier to handle; female ducks are not used for foie gras because of vein patterns on their livers4. Meat by‑products: Ducks yield confit, magret and other value‑added products; geese are used mainly for liver and down. Economics: The EU shift to ducks during the 1980s and 1990s lowered production costs. French producers found that Muscovy ducks were nervous and lost fat during gavage; crossing with domestic ducks produced calmer mulards5.

Traditional cuisine: In Alsace (France) and Hungary, goose foie gras is prized for its milder, creamy flavour and larger lobes. Eastern European and Chinese markets value goose products for cultural dishes. Supply constraints: Geese are rarer and more difficult to rear; their higher price confers prestige. In Canada, imported Hungarian goose liver cost about US$55 per pound in 201117. Duck foie gras from Quebec sold for around US$70 per pound18, though price differences vary by year. By‑products: Goose down and feathers have high value. Geese also produce fat used in regional cuisines.

Although comprehensive price statistics are scarce, producers and retailers report that goose foie gras is generally more expensive than duck because geese are rarer, grow more slowly and require longer feeding. A 2026 article explained that high prices reflect substantial feed and labour costs and the limited supply of fatty livers19. In contrast, duck foie gras is produced at larger scale and is used in pâtés, torchons and emulsified products that are less expensive per kilogram. Whole-lobe goose foie gras is typically sold as a luxury product.

Overfeeding predisposes ducks and geese to several health issues: Liver rupture and internal bleeding due to extreme hepatic enlargement. Respiratory distress because enlarged livers compress the lungs. Skeletal weakness and gait problems from rapid weight gain. Infections and metabolic disorders linked to fat accumulation. Mortality during force‑feeding exceeds 3 % in ducks and 4 % in geese—many times higher than in non‑force‑fed birds13. Mortality rates also increase with longer gavage schedules.

The foie gras industry asserts that birds possess anatomical adaptations (elastic oesophagus, robust liver) that make gavage humane and that livers return to normal weight after the fattening period11. Producers follow veterinary guidelines for hygiene and require birds to be healthy before force‑feeding. However, independent veterinarians and animal welfare organisations disagree. The Canadian Veterinary Journal described the adverse effects on liver function and bird health as unacceptable20. The Food and Agriculture Organization (FAO) has stated that foie gras production raises serious animal welfare issues and is not condoned21. The EU’s Scientific Committee highlighted the inability of birds to carry out normal behaviours when housed in individual cages5.

Industry‑funded research emphasises the reversibility of hepatic steatosis and the absence of inflammatory markers in fatty livers9. Academic studies, however, note that force‑feeding causes non‑pathological hepatic steatosis rather than disease, but the welfare cost arises from stress, restricted movement and high mortality. The debate centres on whether birds experience suffering and whether less invasive methods (e.g., free‑choice feeding) could replace gavage.

Selective breeding aims to improve liver weight, growth rate and feed conversion while maintaining animal welfare. Hybridisation: The mulard hybrid is central to duck foie gras production. Crossing Muscovy males with Pekin or other domestic females combines desirable traits5. Because mulards are sterile, hatcheries maintain parent lines, giving companies control over genetic resources. Genetic selection in geese: Landes and Toulouse geese have been selected for their capacity to develop large fatty livers with minimal pathological changes9. Heritability of liver weight is high, and selection programmes in Hungary and China focus on improved growth and fatty liver yield. Molecular research: A 2020 genome‑wide association study compared geese with high and low fatty liver weights and identified genes (ARAP2, GABRE, LCORL, ZFF36L1) associated with lipid accumulation and body weight. These genes may help breed birds that accumulate fat efficiently with less pathological stress. Technological innovation: In Linqu county (China), companies have developed semi‑automatic feeding machines with sensors that adjust feed volume and frequency, increasing efficiency more than fivefold16. Such technology aims to standardise feeding and reduce labour.

France produces most of the world’s foie gras; it produced ~18 100 tonnes in 2023 according to the French Ministry of Agriculture (72 % of global output)22. The industry is concentrated in Nouvelle‑Aquitaine, Occitanie and Pays de la Loire, where mulard ducks dominate. Force‑feeding is a traditional rural activity and is legally defined as part of France’s gastronomic heritage. Consumers differentiate between duck foie gras (stronger flavour, used for pâtés and blocks) and goose foie gras (milder, used for whole lobes and terrines).

Hungary is the second‑largest producer and largest exporter of foie gras. Hungarian producers favour grey Landes geese and maintain free‑range rearing with hand‑feeding. In 2023, French outlets imported significant quantities of Hungarian goose livers to meet local demand23. Hungary’s climate and sandy soils support goose rearing, and goose foie gras remains part of regional cuisine.

Bulgaria produces mostly goose foie gras for export, utilising semi‑industrial operations. Landes geese are common, and small family farms co‑exist with larger integrators.

Spain produces mainly duck foie gras in regions like Catalonia. Traditional dishes include “foie micuit” and “pintxo de foie.” Spain has fewer farms but benefits from an export market within the EU.

China has rapidly expanded goose foie gras production. Linqu county in Shandong processes 5 million Landes geese annually and produces 5 000 tonnes of foie gras, accounting for about 20 % of global production15. The county imports French geese and has created an integrated supply chain with breeding farms, hatcheries and processing plants. Technological innovation and product diversification (e.g., red‑wine‑infused foie gras) have boosted revenue24.

North America has a small foie gras industry. Hudson Valley Foie Gras in New York produces about 200 tonnes per year and supplies over 500 restaurants25. Canadian production is centred in Quebec; both duck and goose foie gras are made. Geese are rare due to climate; imported goose liver from Hungary costs around US$55 per pound17. Several U.S. cities and states have enacted bans (see Section 9).

Other producing countries include Belgium (notably Flanders), Romania, Turkey, Israel (before its 2005 production ban), Poland, Russia, Egypt and Argentina. Production volumes are modest and often decline due to legal restrictions or avian influenza outbreaks.

Foie gras is expensive because force‑feeding requires specialised labour and high‑energy feed. A 2026 article notes that labour cost and limited supply are the main reasons foie gras is pricey19. In addition, geese require more feed and time than ducks, making goose foie gras rarer and thus costlier. Feed typically consists of maize (corn) for its high starch content and low fibre; some producers use wheat or sorghum14.

The EU exported €69 million worth of foie gras to non‑EU countries in 2024, and intra‑EU trade generated €127 million26. Major importers include Japan and China (which accounted for 28 % of European exports in 2023)27. The EU remains the largest exporter, while Hungary and Bulgaria export most of their production to France. Chinese producers also export goose foie gras, focusing on fresh products (demand is six times greater than for cooked products)28.

Foie gras is sold as whole lobe (foie gras entier), parfait/block (emulsified and often sterilised), torchon (cylindrical), pâté, mousse and canned preparations. Duck livers are frequently processed into pâtés and blocks, making them more affordable. Goose livers are more often sold whole due to their size and texture.

Force‑feeding is prohibited in many jurisdictions on animal‑welfare grounds. According to Compassion in World Farming and the FAO, countries that ban foie gras production include Austria, Czech Republic, Denmark, Finland, Germany, Israel, Luxembourg, Norway, Poland, Sweden, Switzerland and the United Kingdom29. Israel banned production in 2005, and India banned imports in 2014.

California: Enacted a ban on the production and sale of foie gras in 2004 (implemented in 2012). The U.S. Supreme Court upheld the ban after several challenges30. New York City: Passed a sale ban in 2019 but it was repealed in 2024 by the New York Supreme Court due to conflicts with state law31. Pittsburgh (Pennsylvania): Banned the production and sale of foie gras in 202332. Brookline (Massachusetts): Became the first municipality in Massachusetts to ban the sale of foie gras in May 202533. Chicago: Banned foie gras in 2006 but repealed the ban two years later34. European Union: The EU allows foie gras production only if force‑feeding is part of a long‑standing practice; however, 22 of 27 member states have banned force‑feeding6. Producers operate mainly in France, Hungary, Bulgaria, Spain and Belgium.

Bans can reduce imports, as seen when U.S. foie gras imports dropped 19 % in 2023 after California and New York reinforced bans35. Local bans may lead to species substitution, with producers shifting from goose to duck to meet weight requirements or to avoid legal definitions. Some jurisdictions (e.g., Portland, Oregon; Rhode Island proposals) continue to debate bans, reflecting shifting public attitudes.

Production statistics: Publicly available data on global foie gras production are limited. Figures for 2023–2025 rely on industry reports or market research (e.g., 18 100 tonnes produced in France in 202322) rather than official statistics. Animal welfare studies: Industry‐funded research emphasises reversible steatosis and minimal pathology9, whereas independent studies highlight stress and mortality13. Comparative, peer‑reviewed research across different management systems is scarce. Genetic data: Genome‑wide studies have identified candidate genes for fatty liver weight, but breeding programmes incorporate these findings unevenly. Economic data: Price differentials between goose and duck foie gras are often anecdotal. Transparent cost structures for feed, labour and processing would enable better economic comparisons. Legal enforcement: Enforcement of bans varies. Some local bans have been overturned (New York), and it is unclear how import bans are policed. Reliable data on illegal imports or grey‑market foie gras are lacking. Environmental impacts: Limited research quantifies the environmental footprint of foie gras (feed production, waste management), especially in rapidly growing regions like China.

Foie gras production is concentrated in the EU but is expanding in China and remains controversial worldwide. Mulard ducks dominate because they grow quickly, convert feed efficiently and are easier to handle than geese. Goose foie gras persists in certain regions (Hungary, Alsace, China) due to cultural preferences, larger liver size and a milder flavour. Overfeeding induces physiological hepatic steatosis; while birds have adaptive traits, mortality rates during force‑feeding are significantly higher than in non‑force‑fed birds13. Selective breeding and technological innovation continue to optimise liver yield, but ethical concerns drive bans and shifting consumer demand. Data gaps—particularly in economic transparency, welfare outcomes and environmental impacts—limit full assessment. Future research could focus on alternative methods (e.g., natural feeding, genetics) to produce fatty liver without force‑feeding and on comprehensive cost‑benefit analyses that include welfare and environmental externalities. 1 2 Home – Euro Foie Gras : Euro Foie Gras https://eurofoiegras.com/en/home/ 3 The Origin of Ducks – Livestock https://livestock.extension.wisc.edu/articles/the-origin-of-ducks/ 4 Development of hepatic steatosis in male and female mule ducks after respective force-feeding programs - PMC https://pmc.ncbi.nlm.nih.gov/articles/PMC11224645/ 5 8 14 0727.PDF https://food.ec.europa.eu/system/files/2020-12/sci-com_scah_out17_en.pdf 6 Force-feeding in foie gras production | Eurogroup for Animals https://www.eurogroupforanimals.org/what-we-do/areas-of-concern/force-feeding-foie-gras-production 7 Domestic Ducks | Cornell University College of Veterinary Medicine https://www.vet.cornell.edu/animal-health-diagnostic-center/programs/duck-research-laboratory/domestic-ducks 9 Role of miR29c in goose fatty liver is mediated by its target genes that are involved in energy homeostasis and cell growth - PMC https://pmc.ncbi.nlm.nih.gov/articles/PMC6219092/ 10 13 29 Microsoft Word - Foie Gras Factsheet Sept 2010 https://www.ciwf.org.uk/media/3818850/foie-gras-factsheet.pdf 11 The steps – Euro Foie Gras : Euro Foie Gras https://eurofoiegras.com/en/2019/04/24/the-steps/ 12 17 18 23 Foie gras: Duck, duck, and finally some goose - Macleans.ca https://macleans.ca/society/life/duck-duck-and-finally-some-goose/ 15 16 24 28 County in E China's Shandong produces 20 percent of global foie gras - People's Daily Online https://en.people.cn/n3/2025/0702/c98649-20335176.html 19 Why is Foie Gras So Expensive? | TASTE https://tastecooking.com/foie-gras-expensive/ 20 21 30 31 32 33 34 Farmed Animal Welfare: Foie Gras • MSPCA-Angell https://www.mspca.org/animal_protection/farm-animal-welfare-ducks-geese/ 22 25 27 35 Foie Gras Market Size, Share | Global Trends Report, 2035 https://www.businessresearchinsights.com/market-reports/foie-gras-market-108501 26 The figures – Euro Foie Gras : Euro Foie Gras https://eurofoiegras.com/en/2019/03/24/key-figures/