畜牧人

標(biāo)題: Duck Nutrition [打印本頁]
作者: monica    時(shí)間: 2007-7-22 23:17
標(biāo)題: Duck Nutrition
Duck Nutrition
William F. Dean, Ph.D.
Regardless of how ducks obtain their food, whether it be by scavenging, or consuming a complete ration, the food consumed must contain all the nutrients, in an available form, that are needed for maintenance, growth and reproduction. Feeding practices will depend in part on the number of ducks raised. If only a few ducks are kept by a household, and they have access to areas where they can forage, they may be able to survive, grow and lay eggs by consuming available food such as green plants, insects, snails, frogs, and table scraps. Under such conditions, ducks will likely grow very slowly and produce a small number of eggs. Herded ducks are an exception, but they require access to large areas where food is available and the care of a herdsman. If keepers of small home flocks want better growth and more eggs they will have to provide supplemental feed. At a minimum they will have to feed some grain. As the size of a home flock increases, it becomes more likely that the flock will not be able to get enough food by foraging and supplemental feeding will become necessary. If more than a few ducks are to be kept, or if increased performance is desired, there are a number of choices of feeding practices:
(1) If available and affordable, purchase nutritionally complete commercially prepared duck feeds. If duck rations are not available, and chicken feeds are, they will serve as a satisfactory substitute.
(2) If poultry feed concentrates, which when fed with grain constitute a nutritionally complete diet, are available at a reasonable price, this may be a good option. The grain can sometimes be purchased from local farmers at a favorable price.
(3) For those with sufficient knowledge of nutrition and feed formulation, complete duck rations may be mixed on the farm. This approach is dependent upon the availability of feed ingredients and vitamin and mineral premixes at affordable prices. Small batches can be mixed by turning the feed on a clean floor with a shovel.

Nutrient requirements of ducks. Ducks require the same nutrients as chickens, but in slightly different amounts, and particularly in terms of the ratio of each nutrient to the energy concentration of the diet. Suggested nutrient levels for complete duck rations are listed in Tables 1a and 1b. These levels are set high enough to meet the requirements of all breeds of domestic ducks. Requirements more closely tailored to each particular breed are available, and are usually preferred by commercial duck producers. Because correct nutrient levels for a particular ration depend on the energy level of that ration (ducks eat progressively more feed as the energy level is lowered and progressively less as it is raised), nutrient requirements are listed in the tables in reference to a particular energy level. For each type of ration, requirements for a high and a low energy ration are given. Requirements for rations with energy levels different from those listed in the tables, can be calculated using the nutrient/energy ratios in the tables. Examples of complete duck rations are listed in Tables 2a and 2b.

Energy. Ducks, like chickens, have simple stomachs, and therefore cannot digest appreciable amounts of dietary fiber (cellulose, lignin). In contrast to chickens, however, ducks over four weeks of age have an exceptional capacity to consume large quantities of foodstuffs that are high in fiber. When such foodstuffs contain even small amounts of available energy, ducks may be able to consume enough of such foodstuffs to partially or even fully meet their energy requirements. Generally, however, 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 such as corn (maize), wheat, and sorghum grain. Such diets will also result in better feed conversion (less feed required to produce a pound of duck). However when low energy foodstuffs, such as cereal by-products, are available at favorable prices, they can be incorporated into duck rations at fairly high levels, so long as the ration is well balanced. Pekin ducks can grow well on diets containing as little as 1000 kcal/lb (2204 kcal/kg) of metabolizable energy, provided the diet is well balanced and growing conditions are moderately good. Examples of both high and low energy diets are included in Tables 2a and 2b.

Protein. Ducks, like other poultry, do not actually require "protein" but the individual amino acids contained in dietary proteins. The proteins in the diet are broken down during digestion to amino acids which are absorbed and used by the duck to make its own body proteins, such as those in muscle and feathers. Certain of these amino acids must be supplied in the diet because the duck cannot make them from other sources. These are called essential amino acids. When formulating feeds for ducks, primary attention is paid to meeting the ducks essential amino acid requirements. Protein levels that meet the ducks amino acid requirements may vary slightly, depending upon the amino acid content of the ingredients used in each formulation.

Minerals and vitamins. Minerals and vitamins required by ducks and suggested levels of use are listed in Tables 1a and 1b (only those most important in practical rations are listed). Close attention should be paid to calcium, phosphorus and sodium. Note that the phosphorus requirement is expressed in terms of available phosphorus. A large amount of the phosphorus in plants is bound in the form of phytic acid which is unavailable to ducks and other fowl. A rule of thumb used by nutritionists is that only about 1/3 of the phosphorus in foodstuffs of plant origin (cereal grains, soybean meal etc.) is available to poultry. Close to 100% of the phosphorus in inorganic (mineral) sources such as dicalcium phosphate is available. A good source of information on the amount of available phosphorus in foodstuffs is the NRC publication Nutrient Requirements of Poultry. If a duck producer mixes his own feed, the simplest way, and often the most economical as well, is to add vitamins and trace minerals (those minerals listed in Tables 1a and 1b, other than calcium, phosphorus and sodium) in the form of commercially prepared premixes. If it is not possible to use prepared premixes, the next best choice is to purchase the vitamin and mineral sources and make your own premixes. If neither of the above choices are feasible, it will be necessary to include foodstuffs, high in the vitamins and minerals that are lacking, in the ration. Books on duck and poultry nutrition provide helpful advice for preparing vitamin and mineral mixes.

Feeding developing breeders. Meat-type ducks, such as Pekins, that are kept as breeders will become excessively fat (which is detrimental to their health and will impair their reproductive performance) if fed all they will eat during their development prior to lay. It is therefore necessary to limit their daily intake of feed to an amount that will supply all the necessary nutrients that are needed for proper development, while avoiding an excess of calories. For best results, feed restriction should begin at about 2 weeks of age but for practical reasons it is often begun at about 7 weeks. From the time restriction is begun, and up until the breeders are sufficiently mature (about 28 weeks of age for Pekin ducks), their daily feed intake should be limited to 60 - 70 % of the amount they would eat if allowed to eat all they want. Examples of the daily feed allotments for Pekin ducks are given in Table 2b. Feed restriction requires hand feeding a weighed amount of feed to the flock each day. Since the ducks are very hungry at the time of feeding, the feed must be spread out so that all ducks have a chance to eat. Feed can be spread out in long wooden troughs, on a cement slab or on the ground if the area is dry and clean. For more details on restricted feeding, contact the Duck Laboratory.

Feeding laying breeders. Nutrient levels that duck breeder layer rations should contain are listed in Table 1b, and examples of breeder rations in Table 2b. Layer rations contain a higher level of calcium than other duck rations because of the laying duck's need for additional calcium for egg shell formation. A level of 3.00% of the diet is adequate for most breeds of ducks including high egg producing breeds. When enough calcium is included in the ration, it is not necessary to feed oyster shells in addition. However, it will do no harm to make oyster shells available, as is the practice on some duck farms. Some commercial duck producers have found it beneficial to restrict feed to some degree during the laying period. For more information on this question, contact the Duck Laboratory.

Feedstuffs. Examples of feedstuffs that can be used in duck rations are given in Tables 2a and 2b. More information can be found in books on duck and poultry nutrition (see Publications). Some feed ingredients contain substances that are toxic to ducks, and should not be included in duck rations. Groundnut meal (peanut meal) is often contaminated with aflatoxin, a toxin to which ducks are highly sensitive. Groundnut meal should not be used unless tests have proven it to be free of aflatoxin. Rapeseed meal is another feedstuff that is potentially toxic to ducks. Some older varieties of rapeseed meal contain erucic acid and goitrogens at levels high enough to be harmful to poultry. Ducks are much more sensitive to erucic acid than are chickens and turkeys. Genetically improved varieties of rapeseed (Canola) contain much lower levels of these toxins. However even Canola meals should first be tested in ducks before their use in duck feeds on a large scale.

Feed quality. One of the most common causes of poor feed quality is failure to dry grains and other feedstuffs properly before storage. If grains that are too high in moisture are stored, without turning or aeration, the grain will heat up and mold and some of its nutritive value will be destroyed. As explained elsewhere, some molds may produce toxins that are particularly harmful to ducks. Make sure that the grains and other foodstuffs used in duck feeds were properly dried and are free of molds and other contamination. If table scraps, bakery waste, wet mash or other feeds high in moisture are fed, feed only what ducks will clean up in a day. If such feed remains in troughs longer, it will likely become moldy. Feedstuffs that are to be stored for very long should contain no more than 10-12% moisture.

Water. Plenty of clean drinking water should be available to ducks at least 8-12 hours per day. In some management systems it is advantageous to shut off feed and water at night to help maintain litter inside buildings in a dry condition. This applies to breeder ducks or market ducks over 3 weeks of age. If done properly, this practice is not harmful and has no effect on performance during periods of moderate temperatures. During periods when temperatures are above 90ºF, drinking water should be available in the evening until the temperature has dropped below 80°F, or else made available all night. Ducks do not require water for swimming in order to grow and reproduce normally.
However, providing some water for wading or swimming can be beneficial, especially in hot climates. Ducks can expel excess heat through their bill and feet when allowed contact with water that is appreciably below their body temperature (107°F, 41.7°C). Water temperatures of 50-70°F (10-21°C) are ideal for ducks.

Mash or Pellets. It is a well established fact that ducks grow faster, and utilize their feed more efficiently, when fed pelleted rations than when their feed is in mash form. Pelleting all duck rations is common practice in commercial duck production. However, pelleted feeds are not available in many areas of the world, and it may be difficult for small flock owners to get their home mixed feed pelleted. The problem with feeding dry mash to ducks is that it forms a sticky paste when mixed with saliva, which cakes and accumulates on the outer ridges of the mouth. In attempting to free their bills of caked feed, ducks make frequent trips to water to wash their bills, causing feed wastage. Feeding mash also reduces feed intake, and in the case of market ducks, reduces their growth rate. For small flock owners who are not able to pellet their duck feeds, one solution to the problems of feeding dry mash is to feed wet mash. Water is mixed with the mash just before feeding. Enough water is added to form a thick mush without making it watery. Mix only what ducks will clean up within a day.

Pellet size. When pelleted feeds are fed to ducks it is important to avoid feeding pellets that are too large in diameter or too long for ducklings to swallow. For newly hatched ducklings, pellets should be no larger in diameter than 5/32 of an inch (4.0 mm), and no longer than 5/16 inch (7.9 mm). After about two weeks of age, Pekin ducklings can consume pellets 3/16 inch (4.8 mm) in diameter, and approximately ½ inch (12.7 mm) in length, without difficulty.

TABLE 1a. Suggested Nutrient Levels For Duck Rations
Nutrient
Starter
Grower-finisher
(% or amt/kg diet)
High Energy
Low Energy
High Energy
Low Energy
Met energy, kcal/kg (/lb)
3086 (1400)
2646 (1200)
3086 (1400)
2646 (1200)
Protein, % (approx.)
22.0
19.1
16.1
14.0
Lysine, %
1.20
1.04
0.80
0.70
Methionine, %
0.47
0.41
0.35
0.31
Meth + cystine, %
0.80
0.70
0.60
0.52
Tryptophan, %
0.23
0.20
0.20
0.17
Arginine, %
1.20
1.04
1.00
0.88
Valine, %
0.88
0.77
0.80
0.70
Threonine, %
0.80
0.70
0.60
0.52
Histidine, %
0.44
0.38
0.35
0.31
Isoleucine, %
0.88
0.77
0.70
0.61
Leucine, %
1.40
1.22
1.30
1.14
Phenylalanine, %
0.80
0.70
0.70
0.61
Phen + tyrosine,%
1.50
1.31
1.30
1.14
Calcium, %
0.70
0.57
0.65
0.57
Phosphorus, avail, %
0.40
0.35
0.35
0.31
Sodium, %
0.15
0.13
0.14
0.12
Potassium, %
0.60
0.52
0.60
0.52
Magnesium, mg/kg
500
435
500
435
Manganese, mg/kg
50
44
40
35
Zinc, mg/kg
60
52
60
52
Selenium, mg/kg
0.15
0.13
0.15
0.13
Iodine, mg/kg
0.40
0.35
0.40
0.35
Iron, mg/kg
80
70
80
70
Copper, mg/kg
8
7
6
5
Vitamin A, IU/kg
5000
4350
4000
3480
Vitamin D3, IU/kg
600
522
500
435
Vitamin E, IU/kg
25
22
20
17
Vitamin K, IU/kg
2
2
1
1
Choline, mg/kg
1300
1130
1000
870
Riboflavin, mg/kg
4
4
3
3
Niacin, mg/kg
50
44
40
35
Pantothenic a., mg/kg
12
10
10
9
Vitamin B12, mg/kg
0.01
0.01
0.005
0.004
Pyridoxine, mg/kg
3
3
3
3

Table 1b. Suggested Nutrient Levels for Duck Rations
Nutrient
Breeder-developer
Breeder-layer
(% or amt/kg diet)
High Energy
Low Energy
High Energy
Low Energy
Met energy, kcal/kg (/lb)
2866 (1300)
2205 (1000)
2866 (1300)
2646 (1200)
Protein, % (approx.)
17.6
12.8
17.5
16.2
Lysine, %
0.88
0.64
0.80
0.74
Methionine, %
0.38
0.28
0.40
0.37
Meth + cystine, %
0.66
0.48
0.65
0.60
Tryptophan, %
0.22
0.16
0.20
0.18
Arginine, %
1.10
0.80
0.87
0.80
Valine, %
0.88
0.64
0.75
0.69
Threonine, %
0.66
0.48
0.58
0.54
Histidine, %
0.38
0.28
0.37
0.34
Isoleucine, %
0.77
0.56
0.72
0.67
Leucine, %
1.43
1.04
1.22
1.13
Phenylalanine, %
0.77
0.56
0.7
0.65
Phenyla + tyrosine, %
1.43
1.04
1.10
1.02
Calcium, %
0.75
0.55
3.00
2.77
Phosphorus, avail,%
0.40
0.29
0.4
0.37
Sodium, %
0.16
0.12
0.15
0.14
Potassium, %
0.66
0.48
0.60
0.56
Magnesium, mg/kg
550
400
500
465
Manganese, mg/kg
44
32
40
37
Zinc, mg/kg
66
48
60
56
Selenium, mg/kg
0.16
0.12
0.15
0.14
Iodine, mg/kg
0.44
0.32
0.40
0.37
Iron, mg/kg
88
64
70
65
Copper, mg/kg
7
5
6
6
Vitamin A, IU/kg
4400
3200
6000
5580
Vitamin D3, IU/kg
550
400
600
558
Vitamin E, IU/kg
22
16
30
28
Vitamin K, IU/kg
2
2
2
2
Choline, mg/kg
1100
800
1000
930
Riboflavin, mg/kg
4
3
4
4
Niacin, mg/kg
44
32
50
46
Pantothenic a., mg/kg
11
8
12
11
Vitamin B12, mg/kg
0.01
0.01
0.01
0.01
Pyridoxine, mg/kg
3
2
3
3
Note: In addition to the vitamins listed in Tables 1a and 1b, It is suggested that duck rations contain at least 0.25 mg/kg of folic acid a minimum of 0.13 mg/kg of biotin.
Table 2a. Examples of Duck Starter and Grower-finisher Rations
Ration Type:
Starter
Grower-finisher
Energy Classification:
Hi-Energy
Low-energy
Hi-Energy
Low-energy
Energy level, kcal/kg (/lb):
3086 (1400)
2646 (1200)
3086 (1400)
2646 (1200)
Ingredient
%
%
%
%
Ground corn (maize)
64.44
35.37
73.37
47.81
Sorghum grain
---
10.00
---
---
Wheat middlings
---
4.39
3.04
15.63
Wheat bran
---
20.00
---
15.06
Rice bran
---
10.00
---
10.00
Soybean meal, 48.5%
26.54
---
17.20
---
Corn (maize) gluten meal
---
1.63
---
---
Sunflower meal
---
---
---
5.00
Fish meal, menhaden
1.50
8.50
---
5.00
Meat & bone meal
5.00
---
4.87
---
Brewers yeast
---
9.17
---
---
Fat, animl-veg blend
1.51
---
0.56
---
Limestone
0.07
0.21
0.11
0.57
Dicalcium phosphate
---
---
---
0.18
DL-methionine
0.11
---
0.05
---
Salt
0.22
0.15
0.21
0.14
Trace mineral mix
0.10
0.10
0.10
0.10
Vitamin mix
0.50
0.50
0.50
0.50
TOTAL
100.00
100.00
100.00
100.00






Table 2b.  Examples of duck breeder developer and layer rations
Ration Type:
Breeder-developer
Breeder-layer
Energy Class:
Hi-Energy
Low-energy
Hi-Energy
Low-energy
Energy level, kcal/kg (/lb):
2866 (1300)
2205 (1000)
2866 (1300)
2646 (1200)
Ingredient
%
%
%
%
Ground corn (maize)
61.18
17.88
62.49
53.92
Sorghum grain (milo)
---
15.00
---
---
Wheat middlings
14.33
---
5.62
6.14
Wheat bran
---
50.51
---
10.00
Rice bran
---
10.00
---
5.00
Soybean meal, 48.5%
19.50
---
16.68
---
Sunflower meal
---
0.47
---
3.18
Fish meal (menhaden)
---
4.75
1.00
8.00
Meat & bone meal
2.00
---
5.00
2.00
Brewers yeast
---
---
---
5.00
Fat, animl-veg blend
0.38
---
1.50
---
Limestone
0.72
0.62
6.71
6.01
Dicalcium phosphate
0.96
---
0.09
---
DL-methionine
0.08
---
0.09
---
Salt
0.26
0.16
0.22
0.16
Trace mineral mix
0.10
0.10
0.10
0.10
Vitamin mix
0.50
0.50
0.50
0.50
TOTAL
100.00
100.00
100.00
100.00
Feed/duck/day, g
171(490kcal)*
222(490kcal)*
---
---
*Developer is fed on restricted basis, see text for instructions


[ 本帖最后由 monica 于 2007-7-22 23:26 編輯 ]
作者: 翱翔    時(shí)間: 2007-7-23 15:24
Thanks for monica.
Thanks for the duck nutrition.
作者: xishanzhongke    時(shí)間: 2007-7-25 17:16
Thanks for the duck nutrition.;1s:



歡迎光臨 畜牧人 (http://ffers.com.cn/) Powered by Discuz! X3.5