By Prof. Ross Gordon Cooper
Searches for articles in the literature pertinent to the care of ducks revealed 49 papers and two manuals specialising in duck husbandry. Relevant details thereof are alliterated below.
Recent cloning experiments in ducks has utilised experiments investigating immunologically-mediated enzymatic reactions to determine activities of certain interleukins, clearly with the view of duck disease monitoring. Studies of the like are essential in complexes with numerous ducks, and potential contamination from wild birds. Other interesting experiments include the use of AFLP fingerprinting technologies for paternity testing in ducks. Selective breeding in ducks shows that there is increased fertility and hatchability at day 2 and 8 after artificial insemination, with the highest increase of fertility between days 5 and 11. In this regard it is also important to determine the egg production per duck-day, feed efficiency and egg weight in crosses. The use of herding robots that are smaller in stature than humans result in less aversion amongst flocks, but the practicality of such is questionable.
The management of duck concerns depends on their size. The small home flock kept in a yard would include a simple, partially-enclosed shed, cheap wire fencing, a feed hopper or trough made of wood and a simple watering devise such as an inverted steel funnel of water on a metal tray. If trough systems are used then the drinking area should be wide enough, ca. 4cm, for the duck to submerge its bill. For starting and growing ducks a minimum of about 2.5cm, of linear watering space should be allowed per duck, increasing to 5cm per duck for developing and laying breeders. Sandy soils are useful as it drains away after the rains. The brooder house should be sprinkled with straw or shavings to catch the excreta. In the larger concern ventilation systems are needed in the enclosed areas to remove the excess moisture and maintain optimum temperatures. The building must prevent wild birds roosting therein. At hatching, ducklings need a high temperature of 30ºC with supplemental heat provided by the brooder. At 35 days of age starter ducks and grower-finisher ducks can adequately thrive at temperatures of 12.7 and 10.6ºC, respectively. The floor space for ducks increases with age from 289 to 2809 cm2/duck aged 1 day and laying breeders, respectively. The texture of flooring is critical to prevent injury to feet and hock joints of ducks and therefore stones should be avoided and any wire should only occupy one-third of the floor surface. The length of the laying period of ducks can be greatly increased if supplemental lighting is provided. Ducks will lay continuously for 7-12 months if artificial light is provided constantly for 14 hours. Supplemental lighting for the first three weeks of life will assist ducklings to find food.
According to the Duck Laboratory associated with Cornell University, USA, eggs from common ducks like Pekins require 28 days to hatch. Eggs from Muscovy ducks hatch in about 35 days after setting. When larger numbers of duck eggs are to be hatched, large commercial incubators (setters) and hatchers are normally used. Pekin duck eggs are kept in a setter for 25 days and then transferred on the 25th day to a hatcher where they remain until they hatch on the 28th day. Eggs are automatically turned while in the setter (usually hourly), but not in the hatcher. Basic procedures and conditions for hatching duck eggs are as follows. Set the temperature at 37.5°C and relative humidity at 55%. Set ventilation as recommended by the incubator manufacturer. Eggs must be turned, either automatically or by hand, a minimum of 4 times a day. Most automatic turning devices are set to change the position of the eggs hourly. Select eggs to be set by carefully inspecting and candling them at the time they are put in setting trays. Do not set eggs that are cracked, double yolked, misshapen, oversized, undersized or dirty. For best results, set eggs within 1-3 days from the time they were laid. On the day of setting, put eggs in incubator, close the doors and allow the incubator to reach operating temperature.
At about seven days after setting, candle the eggs and remove any eggs that are infertile (clear) or have dead germ (cloudy). At 25 days after setting (Pekin eggs), the eggs are transferred to hatching trays, and if eggs are hatched in a separate machine, moved to the hatcher. Candle and remove eggs with dead embryos. At the time of transfer, the temperature of the hatcher should be set at 37.2°C and the humidity set at 65%. As the duckling develops inside the egg there is a loss of water from the egg and an increase in the size of the air cell. If the duckling is developing normally, the air cell should occupy about one-third of the space inside the egg at 25 days of incubation (common ducks). Weight loss can also be used as a guide. Common duck eggs should lose about 14% of their weight at time of setting by 25 days. Duck eggs may be hatched naturally by placing them under a broody duck or even a broody chicken hen. Muscovy ducks are very good setters, capable of hatching 12-15 duck eggs. The nest box should be located in a clean dry shelter, bedded with suitable litter. Feed and water should be available for the broody duck and for the ducklings when they hatch. If eggs are stored for a while before they are set, they should be stored at a temperature and humidity level that will minimize deterioration of the egg. For a small number of eggs, storage in a cellar may suffice. Whenever possible, store eggs at about 13°C and 75% relative humidity. Store eggs small end down.
When a duck is stressed, it may engage in more frequent feather pecking. Stress may also be associated with reduced lighting, high stocking density, forced separation of sexes, feeding of a single high calorie diet, etc. The practice of beak-trimming in Pekin ducks to reduce feather pecking and cannibalism has been criticised due to induction of pain. The trimming of beaks and toes should always remain strictly to the horny parts. A study has shown that tip-searing as apposed to trimming with cautery, may be a preferably method as it is associated with less adverse effects on weight gain and has fewer bill morphological changes.
The feeding behaviour of ducks, particularly individual feeding, is very important to study especially considering the pattern of meal type and interrelations among meal type, body weight, feed intake, and frequency of consumption are important. It has been found that the frequency of short duration meals declines with age of the duck, whereas the frequency of consumption of larger meals increases. An experiment of domestic drakes showed that the yielded estimates of maintenance requirements of 583 and 523 kJ/kg b.wt./day at 10 and 26ºC, respectively. It is interesting to note that brewery waste can replace traditional diets for crossbred common ducks, especially if there is replacement of half of the feed concentrate which results in improved growth performance. The effect of cecetomy on nutrient digestibility in ducks is dependent on the feedstuff assayed. Intact ducks have a greater ability to utilise energy in wheat middlings. Phytase may be used in finisher diets of ducks from 3-6 weeks of age to improve growth performance and leg bone development.
The feed regime of ducks is important for optimal productivity. Ducks grown for meat are more likely to attain optimal performance when their diet contains a high proportion of cereal grains that are high in available energy like maize, wheat and sorghum grain. Pekin ducks can grow well on rations containing as little as 2,204 kcal/kg of metabolisable energy. The metabolisable energy in high and low energy starter feed is 3,086 and 2,646 kcal/kg, respectively, and the grower-finisher 3,086 and 2,646 kcal/kg, respectively. Amino acids requirements are derived from a protein inclusion of 22.0 and 19.1% for high and low energy starter, and 16.1 and 14.0% for high and low energy grower-finisher rations. In duck rations, close attention must be paid to calcium, phosphorus and sodium. Calcium inclusion should be 0.70 (high energy starter) and 0.57% (low energy starter), respectively. In the grower-finisher, calcium inclusion is 0.65 (high energy) and 0.57% (low energy), respectively. The percentage available phosphorus in starter [0.40 high energy and 0.35 low energy] and grower-finisher [0.35 high energy and 0.33 low energy] is critical. Sodium inclusion in duck starters is 0.15% (high energy) and 0.13% (low energy), and in grower-finisher 0.14% (high energy) and0.12% (low energy). Feed restriction is usually commenced at ca. 2 wk but often, practically at ca. 7 wk. When the breeders are sufficiently mature at ca. 28 wk. their daily feed intake should be limited to 60-70% of total consumed. Some duck farms provide oyster shells for feeding breeders.
Duck housing biosecurity needs to include aspects of fresh litter usage, cleaning of sheds between batches of birds, and efficient maintenance of single age flocks. The removal of odour from duck confinement building has met with much interest and the biofilter system was approximately 95% efficient at removing the smells. However, fabric fibres used for pre-treatment to protect the biofilter from clogging up from duct and feather particles, would result in a considerably increased operating cost, hence necessitating alternative methods. Possibly the use of fan-spray technologies would assist. Hazard analysis critical control points should be established fro bacteria like Campylobacter and Salmonella.
Water supply for ducks to assist in plumage condition has been investigated using a variety of water supply systems. In free-choice pens the use of open water systems were preferred and stimulates duck activity. Limiting access to open water systems leads to increased use within the time period. Ducks with access to nipple drinkers showed a larger percentage of plugged up nostrils than birds from pens with open water drinkers. The latter had a positive impact on plumage condition. The provision of fresh, shallow daily water bathing is useful, although one should be always conscious of the effects of dirt water in duck health.
Mating activity in ducks is influenced by the quality of duck houses, genetic factors, and the size of footpads. Indeed, the higher the body weight, the higher the size of footpads and the lower the mating frequency. Mating in ducks is also diminished at the end of the laying period. In ducks in captivity periods of maximum female fertility do not coincide with the periods of greatest sexual activity, suggesting that natural mating is not consistent with optimal female reproductive performance under artificial conditions.
The possible transmission of Avian Influenza to a man from ducks is real, particularly from free-range ducks such as the mule duck (a cross between Muscovy and Pekin ducks). Swabs in studies have determined the presence of AI subtypes (H5N1, H5N2, H5N3, H6N2, H6N8 & H11N9). In a study of domestic ducks in Thailand, no AIV was detected in ducks raised in closed houses with high biosecurity, although it was prevalent amongst ducks in open houses, free-ranging (grazing) ducks and back-yard ducks. Human, duck and swine influenza A viruses may spread among human duck and pig communities interchangeably. The risk of spread from wild ducks and poultry emphasises the need to assess the immunity status afforded by available vaccines. Workers on duck farms have to be appropriately attired and exert extreme caution to prevent infection. Other possible diseases from rural duck abattoirs include ornithosis from exposure to Chlamydophila psittaci resulting in pneumonia amongst workers. High exposure to blood and feathers from recently-killed ducks is likely to increase infection rates, necessitating stringent respiratory protection for abattoir workers and highly efficient airflow and eliminated environmental contamination. One study cautioned on the use of antimicrobials in birds due to the potential emergence and spread of multi-drug resistant vancomycin-resistant enterococci, with adverse implications on human health. If this is compounded with weakened cellular and immunological defences due to inadequate management and husbandry practices and severe genetic manipulation for fast growth and high productivity, then the duck industry is threatened. In this regard, embryological studies of duck embryos are called for.
Many influenza A virus strains in waterfowl and wild ducks are capable of infecting poultry, although good husbandry and control measured prevented this. This suggests the need to adequately manage wood ducks on private lands and waters. Habitat can be created by diverting water from streams into impoundments or by catching runoff and spring water behind dams. Ponds built for ducks should be shallow and contain one or more islands. Gentle slopes on the islands will enable the ducks to walk up slowly. An efficient drainage system will lower water levels and expose the pond bottom. Natural vegetation including reeds will attract and hold ducks. Ducks hatched in nest boxes will likely choose the like for their own nests. It goes without saying that all ducks should be vaccinated against AIV.
Vaccination of ducks includes the following products:
- Riemerella anatipestifer vaccine.
- Duck virus hepatitis vaccine.
- Duck virus enteritis vaccine.
- E.coli and R. anatipestifier bacterin.
- Autogenous bacterin.
Avian cholera and colibacillosis can be prevented through good sanitation techniques and the use of sulphurdimethoxine-ormetroprim (0.02-0.04%) and chlortetracycline (0.044%) in the feed are effective treatments. Aspergillosis can be avoided by using dry straw and preventing moist feed. Contaminated feed is always a concern to the duck farmer and ducks fed diets containing soybean meal or peanut meal were more affected by aflatoxins than those fed diets with fish meal.
Ducks are often kept conveniently as a source of eggs, meat and feathers, including Pekin, Aylesbury and Maya ducks. The farmer selects a duck that has a moderate body size and good egg production. Duck meat has a unique flavour and is a very good source of amino acids, iron, phosphorus, zinc, copper, selenium, thiamine, riboflavin, niacin, pantothenic acid, vitamin B6 & B12, and smaller amounts of potassium, magnesium, vitamins, E, A & C and folic acid.
Images by Prof. Ross Cooper