Ducks are waterfowl belonging to the Anatidae family of cosmopolitan distribution. In duck production systems, obtaining ducklings at one-day-old is determinant for the productive chain. The egg production in some species of ducks reaches about 250 to 300 eggs per year. Obtaining one-day-old ducklings can be done by natural incubation with a broody female duck or artificially in an incubator. During artificial incubation, fertility and hatchability are the most important indicators that must be controlled, because they influence the supply of ducklings to the farm. Many factors are related to fertility and hatching, such as environmental conditions, production system, season, nutrition, management of broodstock, storage time of egg and cleaning of eggs before the incubation. According to some reports, Pekin eggs have greater hatchability than Muscovy eggs. The eggs of Muscovy have presented values lower than 22.7% of hatchability. The hatchability of Pekin duck eggs was 78.0% in the spring, while in summer it was around 46.5%. The best hatchability is observed during the winter (57.68%), as in the summer it decreases to 54.14%. The reproductive characteristics of flocks, age, external and internal quality of the egg, male female relation, and presence of lethal genes are factors that directly involve breeders. Larger sexual ratios between males and females of 1:4.3 to 1: 10 cause reduced egg fertility from 75.9% down to 49.6%. Successful production of day-old ducklings starts with the proper selection and management of breeding stock, proper post-lay handling of fertile eggs and the correct incubation process. There are different methods used to improve the hatchability such as dipping eggs in nutrients during the incubation period.

Curcumin has been attributed with antioxidant, anti-inflammatory, antibacterial activities, and has shown highly protective effects against enteropathogenic bacteria and mycotoxins. Ochratoxin A (OTA) is one of the major intestinal pathogenic mycotoxins. The possible effect of curcumin on the alleviation of enterotoxicity induced by OTA is unknown. The effects of dietary curcumin supplementation on OTA-induced oxidative stress, intestinal barrier and mitochondrial dysfunctions were examined in young ducks. A total of 540 mixed-sex 1-day-old White Pekin ducklings with initial BW (43.4±0.1 g) were randomly assigned into controls (fed only the basal diet), a group fed an OTA-contaminated diet (2 mg/kg feed), and a group fed the same OTA-contaminated feed plus 400 mg/kg of curcumin. Each treatment consisted of six replicates, each containing 30 ducklings and treatment lasted for 21 days. There was a significant decrease in average daily gain (ADG) and increased feed : gain caused by OTA (P<0.05); curcumin co-treatment prevented the decrease in BW and ADG compared with the OTA group (P<0.05). Histopathological and ultrastructural examination showed clear signs of enterotoxicity caused by OTA, but these changes were largely prevented by curcumin supplementation. Curcumin decreased the concentrations of interleukin-1β, tumor necrosis factor-α and malondialdehyde, and increased the activity of glutathione peroxidase induced by OTA in the jejunal mucosa of ducks (P<0.05). Additionally, curcumin increased jejunal mucosa occludin and tight junction protein 1 mRNA and protein levels, and decreased those of ρ-associated protein kinase 1 (P<0.05). Notably, curcumin inhibited the increased expression of apoptosis-related genes, and downregulated mitochondrial transcription factors A, B1 and B2 caused by OTA without any effects on RNA polymerase mitochondrial (P<0.05). These results indicated that curcumin could protect ducks from OTA-induced impairment of intestinal barrier function and mitochondrial integrity.

In order to avoid excess feed consumption during the force-feeding period in foie gras production, a dose-response experiment with seven feed consumption levels (450, 540, 630, 720, 810, 900, 990 g/day per bird) was conducted to evaluate the effects of feed consumption levels on growth performance and carcass composition of male Mule ducks from 91 to 102 days of age. One-day-old Mule ducklings (sterile and artificial hybrid of male Albatre Muscovy duck and female Pekin duck were fed a two-phase commercial diets for ad libitum intake from hatching to 91 days of age, followed by graded feeding levels of a corn diet by force-feeding from 91 to 102 days of age. Fifty-six 91-day-old male Mule ducks with similar BW were randomly assigned to seven treatments, with eight birds per treatment. Birds were housed in individual pens. At 102 days of age, final BW was measured and BW gain and feed conversion ratio of ducks from each treatment were calculated from day 91 to 102, and then all ducks were slaughtered to evaluate the yields of skin with subcutaneous fat, abdominal fat, breast meat (including pectoralis major and pectoralis minor), leg meat (including thigh and drum stick), and liver. Significant differences in BW gain, total liver weight and liver relative weight were observed among the treatments (P<0.001). According to the broken-line regression analysis, the optimal feed consumption levels of male Mule ducks from 91 to 102 days of age for maximum BW gain, total liver weight and liver relative weight were 217, 227 and 216 g feed/kg BW0.75·per day, respectively.

An experiment was conducted to investigate the effect of arginine on feed intake regulation. One hundred and twenty six 1-day-old male White Pekin ducks (Anas platyrhynchos domestica) were randomly were allotted to one of two dietary treatments. The birds were fed diets containing 0.71% (deficient) or 1.27% (sufficient) arginine for 3 weeks. At 21 days of age, feed intake was determined and hypothalamic protein profiles were analyzed using isobaric tags for relative and absolute quantification technique. The birds fed with arginine-deficient diet had a lower final live BW and cumulative feed intake (P<0.01) than those fed with arginine-sufficient diet. A total of 16 proteins were identified in the hypothalamus with >1.5-fold expressional changes between arginine-deficient and -sufficient dietary treatments. Nine of these proteins were upregulated and seven of them were downregulated. The identified proteins could be regrouped into six categories: protein processing, carbohydrate metabolism and energy production, transporter, cytoskeleton, immunity and neuronal development. Dietary arginine deficiency decreased expression of proteins involved in energy production (glycine amidinotransferase, aldolase B fructose-bisphosphate, aconitase, transaldolase, 6-phosphofructokinase type C-like) and oxygen transportation (haemoglobin subunit α expression). The proteomic alterations described here provides valuable insights into the interactions of arginine with appetite.

The effects of different dietary amounts of organic and inorganic Zn were studied in male White Pekin ducks (WPD) from 1 to 56 days of age. The control diet (26 ppm of Zn from raw ingredients) was supplemented with 30, 60 and 120 ppm of Zn from both inorganic and organic sources, for a total of seven treatment groups, each containing five replicates of nine 1-day-old ducklings each. BW, feed intake and feed conversion ratio (FCR) were recorded at 1, 28 and 56 days of age. At 56 days of age, five birds per group were used in a digestibility trial to measure Zn retention and excretion. At the end of the trial, five birds per treatment were slaughtered and carcass traits as well as Zn content in tibia and liver were measured. Samples of blood from five birds per treatment were used to measure plasma concentration of Zn and Cu. BW gain during the entire period of the trial increased (P < 0.001) by 30 and 60 ppm of Zn. Increasing Zn contents progressively increased (P < 0.001) the tibia and the liver Zn contents as well as the plasma Zn and Cu contents. The concentration of 120 ppm of Zn increased (P < 0.001) tibia ash and decreased (P < 0.001) abdominal fat in the carcasses. In the period 1 to 56 days, Zn oxide increased (P < 0.001) growth rate and improved (P < 0.03) FCR compared with organic Zn, whereas organic Zn increased (P < 0.003) the dressed carcass percentage. Organic Zinc increased (P < 0.001) Zn and Cu concentration in the plasma. A level of 30 ppm of Zn from an inorganic source was adequate for male WPD during 1 to 56 days of age, based on positive effects of growth rate and Zn excretion.

Ducks are considered to play an important role in the transmission and maintenance of the Highly Pathogenic Avian Influenza (HPAI) virus. However, there is limited information on duck management practices in countries where HPAI is endemic. A cross-sectional questionnaire survey was conducted on 96 ‘stationary’ smallholder duck farms in Indonesia to describe the management of ducks and to identify practices that could potentially promote the risk of HPAI spread. The mean flock size was 29 ducks, ranging from 1 up to 150 birds. Both the sale and the consumption of eggs were the most important purposes of duck keeping, followed by the use of droppings for fertilizer and the production of meat ducks. About 77% of duck owners allowed their ducks to scavenge. Important hazards for interspecies HPAI virus transmission related to scavenging were identified: 1) intermingling between ducks and chickens on duck farms (48%); 2) frequent contact with neighbours’ chickens (44%); 3) visits to the same paddies by duck flocks from other farms (88%); 4) in the paddies, contact between duck flock and other ducks, chickens, people and wild birds as reported by 88%, 30%, 80% and 77% of duck owners respectively; 5) the keeping of singing birds by 17% of farmers; 6) predators such as the small Asian mongoose (Herpestes javanicus) (25%) and feral cats (20%) visiting the duck farms (these species are susceptible to HPAI infection and might play a role in the spread of the HPAI virus). Many duck owners associated deaths of their birds with the use of pesticides in the rice paddies, and appeared to be more concerned about pesticide toxicity, problems that inhibit scavenging ability and external parasites than about HPAI, which in general was not considered to be of high importance. Hence HPAI vaccination or preventive culling of ducks during disease outbreaks was not conducted on the study farms.

A prospective longitudinal study was conducted on 96 smallholder duck farms in Indonesia over a period of 14 months in 2007 and 2008 to monitor bird- and flock-level incidence rates of H5 highly pathogenic avian influenza (HPAI) infection in duck flocks, and to identify risk factors associated with these flocks becoming H5 seropositive. Flocks that scavenged around neighbouring houses within the village were at increased risk of developing H5 antibodies, as were flocks from which carcases of birds that died during the 2 months between visits were consumed by the family. Duck flock confinement overnight on the farm and sudden deaths of birds between visits were associated with lower risk of the flock developing H5 antibodies. Scavenging around neighbouring houses and non-confinement overnight are likely to be causal risk factors for infection. With this study we have provided insights into farm-level risk factors of HPAI virus introduction into duck flocks. Preventive messages based on these risk factors should be included in HPAI awareness programmes.

This study investigated the effects of various stunning methods on the quality of French ‘foie gras’ in ducks and geese. The ducks (n = 30 per group) were stunned with one of the following techniques: electrical stunning in a water bath (50 Hz AC, 130 mA, 4 s), head-only electrical stunning (50 Hz AC, 600 mA, 4 s), mechanical stunning (captive bolt) and controlled atmosphere stunning (CAS: phase 1, CO2 (40%)–O2 (30%)–N2 (30%), for 2 min followed by phase 2, CO2 >85% in air, for 2 min). The same methods (except head-only stunning which was not applied) were used in geese (n = 40 per group). The weight of the liver at slaughter was not affected by the stunning techniques, neither was its colour (L*, a*, b* coordinates), despite the differences in bleeding rate between the stunning treatments. The loss of fat during the cooking of canned fatty liver did not depend upon stunning treatment. Some appearance defects of raw fatty livers were significantly affected by the treatment: mechanical and head-only stunning induced higher incidence of petechial haemorrhages in duck liver, whereas in geese, incidence of superficial haemorrhages was significantly higher after CAS and water-bath stunning. The calculation of an overall score based on the incidence and severity of the different appearance defects observed in the present experiment showed that CAS was associated with the least favourable position in ducks as well as in geese, compared to the other treatments. The commercial grading of ducks and geese fatty livers, carried out by an expert from the industry, clearly showed the detrimental effect of CAS on the commercial value of raw livers. CAS, under the conditions applied in the present work cannot be recommended, because of its drastic effect on liver quality. The underlying mechanisms deserve further investigations.

This study investigated the effects of various stunning methods on the quality of carcass and meat in ducks and geese force-fed for the production of French ‘foie gras’. The ducks (n = 30 per group) were stunned with one of the following techniques: electrical stunning in a water bath (50 Hz AC, 130 mA, 4 s), head-only electrical stunning (50 Hz AC, 600 mA, 4 s), mechanical stunning (captive bolt) and controlled atmosphere stunning (CAS: phase 1, CO2 (40%)–O2 (30%)–N2 (30%), for 2 min followed by phase 2, CO2 > 85% in air, for 2 min). The same methods (except head-only stunning which was not applied) were used in geese (n = 40 per group). During the first 5 min after slaughter, the stunning techniques that did not kill the animals were associated with a high incidence of head movements (mechanical and electrical head-only stunning), convulsions and convulsive wing flapping (mechanical stunning), in both species. Consequently, the rate of post-mortem pH fall in breast muscle was enhanced and the meat was paler when measured at 24 h or 6 days post mortem (L*, a*, b* coordinates). In ducks, the animals stunned in the water bath showed the lowest bleeding efficiency, compared to the three other procedures. In geese, the mechanical stunning allowed the highest recovery of blood compared to the CAS and the water-bath methods. Meat texture assessed instrumentally and fluid losses during storage and processing were not affected by the stunning method in any species. Sensory analysis showed a higher score for bloody appearance of raw meat in ducks stunned with the methods that kill before neck cutting (water-bath and CAS). This effect was, however, not linked to the rate of bleeding. The sensory properties of cooked meat were not affected by the stunning method. In both ducks and geese, CAS was associated with the lowest rate of fractures of humeral bone but CAS-stunned geese showed the most engorged wing veins. Overall, these results show the positive effect of CAS on the appearance defects of carcass and meat of ducks and geese, and, on the contrary, they confirm the detrimental effects of water-bath stunning on these criteria. However, the incidences on meat sensory qualities were scarce.

Using microsatellite markers, the genetic structure of nine domestic duck (Anas platyrhynchos) populations in eastern China was analysed. The results showed that the heterozygosity was high in these populations, ranging from 0.5137 to 0.6055, with an average heterozygosity of 0.5523, reflecting the rich diversity. Considerable breed differentiation was observed and 25.65% of the total genetic variation came from breed differences; this low differentiation result affirmed that each breed has its own genetic diversity. The DA genetic distances suggested that greater differentiation existed between populations. The duck populations were clustered into four groups based on neighbour joining (NJ) clustering, and the clustering results showed relationships with duck breed distributions and economic utilization.

The accretion of methionine and protein as a function of methionine intake was assessed in growing ducks between 22 and 42 d post-hatching. Four graded doses of dl-methionine at 0, 0·5, 1·0 or 1·5 g/kg diet were added to a methionine-limiting basal diet and fed to four replicate groups of four ducks each. The growth and efficiency of food use for growth increased linearly (P < 0·05) as a function of methionine intake. The accretion of body protein increased (P < 0·001) from 87·5 to 182·2 g, and that of methionine from 1616 to 3125 mg, over the 21 d period as dietary methionine increased. The accretion rate of methionine in the body (y, mg/d) as a function of methionine intake (x, mg/d) of ducks fed diets containing supplemental methionine at 0, 0·5, 1·0 or 1·5 g/kg diet from day 22 to day 42 post-hatching gave the regression equation: y = − 148·86 (se 32·558)+0·312 (se 0·0384)X, r2 = 0·8253. For protein accretion rate in the body (y, mg/d) as a function of methionine intake (x, mg/d), the regression equation was: y = − 9782 (se 2204)+19·505 (se 2·5994)x, r2 = 0·8009. There was a linear relationship between methionine (y, mg/d) and protein (x, mg/d) accretion in ducks that was described by the equation y = 12·757 (se 7·4019)+0·01 525 (se 0·00 107)x, r2 = 0·9355. The results of these studies suggest a constant utilisation of methionine over the range 2·4–3·9 g digestible methionine/kg diet, with an efficiency of 31 %. Furthermore, the results suggest a quantitative relationship of 15 mg methionine for every gram of protein accretion.

The effects of age (from 1 day post-hatch to 98 days of age) and feeding levels (feed restriction followed by overfeeding v. ad libitum feeding) on lipid deposition in breast muscle (quantity and quality, localisation) of mule ducks were determined in relation to muscle energy metabolism (glycolytic and oxidative), plasma levels of lipids, glucose and insulin, and muscle capacity for lipid uptake (characterised by lipoprotein lipase (LPL) activity). Two periods were defined for age effects on intramuscular lipids in breast muscle: − 1 to 42 days of age when lipids (mainly phospholipids and cholesterol provided by egg yolk) stored in the adipocytes during embryonic life were transferred to the muscle fibres and used for growth and energy requirements, − 42 to 98 days of age when the muscle again stored lipids (mainly triglycerides provided by liver lipogenesis), first in fibres and then in adipocytes.

Plasma glucose and insulin levels were not affected by age. Plasma levels of lipids and LPL activity in breast muscle were high at 1 and 14 days of age and then decreased, remaining stable until 98 days of age. Energy metabolism activity in the breast muscle (mainly glycolytic activity) increased with age.

Feed restriction, corresponding to 79% of ad libitum intake, applied between 42 and 75 days of age only resulted in decreases in plasma insulin concentration and total lipid content of breast muscle, mainly affecting triglyceride and mono-unsaturated fatty acid (MUFA) levels. Overfeeding increased plasma levels of insulin and lipids while glycaemia remained stable. LPL activity and total lipid levels increased in breast muscle, mainly induced by deposition of triglycerides and MUFA occurring particularly during the 2nd week of this period. Glycolytic energy metabolism decreased.

In response to age or feeding levels, muscle lipid levels and composition reflect plasma lipid levels and composition and high muscle lipid levels stimulate oxidative energy metabolism.

Optimal utilisation of limited phosphate resources in animal feeding requires detailed knowledge of both the requirement for available phosphorus (P), and the availability of P from relevant feed ingredients. In growing ducks, the P concentration of gained body weight and the inevitable P losses voided determine the requirement for available P. The concentration of available P needed in the diet then depends on the feed conversion ratio. Plant and mineral feedstuffs contribute to the available P content of the diet depending on their respective availability. This review summarises the literature on P nutrition in ducks with regard to factors affecting P requirement and considerations of P availability, including the use of microbial phytase. Most of the published data refer to the Pekin duck. The P content in body weight gain is 5.0–5.5 g/kg in young ducks, and it probably decreases with age. The ratio of Ca to P in body weight gain is about 1.8:1. Inevitable P losses are not yet quantified and can only be estimated to account for 1 g/kg of feed intake. Availability of P from plant-based diets without P supplements and phytase ranged between 28 and 49%. Availability of P from different mineral sources ranged between 77 and 100%. Microbial phytases were efficient in improving the availability of P from plant-based diets. A simple model is presented, which allows flexible calculations to be made of the necessary P concentrations in the diets for ducks. The most efficient tool for reducing the use of P sources is the frequent adjustment of the dietary P content during the growth period. Data from growth studies indicate that the suggestions made herein are sufficiently safe for application in Pekin duck feeding.

A comparative study was undertaken on the performance of Khaki Campbell, Desi ducks and their reciprocal crosses in the Darrang District of Assam (India). Four hundred and seventy ducks were studied for certain economic traits. Results of the study in respect of age at maturity, body weight, egg production, egg quality, mortality and economic performance from the flocks are highlighted.

Force-feeding is a very old practice, first recorded in ancient Egypt, but until the 1950's foie gras production remained somewhat limited in volume. Foie gras is currently produced in various countries but approximately 80% of world production and consumption takes place in France.

Geese, which were the most common specie been force-fed until recently, now account for less than 10% of the total world foie gras production. Ducks such as the Muscovy duck (Cairina moschata) account for less than 5%, and mule ducks for the rest. Thus, over 35 million mule ducks were force-fed in France in 2001, accounting for nearly 95% of the domestic foie gras production. This increase was made possible by technical progress in specific breeding programmes and force-feeding practice.

However, the future of this production is uncertain, at least in Europe. Indeed, although a number of experimental approaches have shown that there is no scientific evidence that validates such adverse comment, this procedure is highly criticised in terms of animal welfare. The Council of Europe therefore adopted two specific recommendations in 1999 and although its practice is not banned at present, it is limited to the areas where it is already practised and only under specific rearing conditions. Therefore, the question is: will it be still possible to produce foie gras in France or elsewhere in Europe in the future and, if not, where and how will it be produced?

Few descriptions of traditional duck farming in Vietnam are available. This small study reports on these traditional techniques before they disappear as a consequence of the country's rapid economic and social development. Five production farms and two hatcheries located in South Vitenam were evaluated. The study covered basic questions relating to farm and hatchery management, nutrition, vaccination, pharmaceutical use, costs and priority needs. Questions were translated into Vietnamese for personal interviews. Out of five production farms, three did not use the local veterinary services. However, four used a French duck plague vaccine and not the Vietnamese product. There was little knowledge on the appropriate use of pharmaceuticals. Hatching methods within the two hatcheries were similar to those of South China. The traditional farming systems made efficient use of a scavenging resourcefulness of Vietnamese farmers in their present situation, and identified areas for disease control and research.