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Contents
INTRODUCTION
TABLEWORKS OF NUTRIENT REQUIREMENTS
AND
NUTRIENT CONTENTS OF FEEDSTUFFS
POULTRY FEEDS SHOULD BE HEAT TREATED
FEED STRUCTURE SHALL BE COURSE
STARCH RICH ENERGY FEEDSTUFFS
Maize
Wheat
Barley
Oat
Rye
Triticale
Rice
Cassava
(tapioca, yuca, manioc)
Cereal byproducts
Distillers solubles
PROTEIN FEED SOURCES
Soy
Rapeseed
Cotton-, peanuts-, sunflower-, linseed meals
Hampseed
Peas
Lupines
Potatoproteins
Maizegluten meal lucern meal and other pigment sources
Fishmeal
Meat meal
FAT
AMINO ACIDS
MINERALE FEEDSTUFS
VITAMINS
ENZYME PREPARATIONS, FEED ANTIBIOTICA AND COCCIDIOSTATS
PROBIOTICS AND PREBIOTICS
REFERENCES
Table 1. Contents in some feedstuffs of protein, fat and carbohydrates (Schutte
et al., 1990) (% in DM) and metabolizable energy for poultry
Table 2. Effect of feed antibiotics and enzyme preparations on growth
rate and feed efficiency of broilers
Table 3. Nutrient contents of feedstuffs
Table 4. Feedstuffs ranked according to protein methionine content.
Protein total contents of sulphur amino acids (met+cystin/cystein) and
lysine in feedstuffs, as well as is
Exemple of feed declaration of commercial layer diet
Exemple of feed declaration of commercial broiler diet
This presentation is teaching
material meant to aid in exercises in feed optimization of poultry
diets. You also need to have access to data of nutrient requirements and
nutrient contents of feedstuffs. This is presented in different kinds of
table works. For further information this presentation is supplemented
with internet links to further and deeper information.
These
links may bring you to different kind of websites, such as authorities,
universities and private companies, depending of what is available.
The Table of nutrient recommendations
mostly referred to is National
Academy Press (NRC), Nutrient Requirements of Poultry.
Such information is also supplied by breeder companies adjusted to
assumed needs of different genotypes. See for instance recommendations
by the company
Hyline where the
production manual also includes data of different feedstuffs.
Aviagen and
Cobb-Vantress are
presenting data for their broilers Ross and Cobb, respectively. Content
of metabolizable energy in different feedstuffs to be used by feed
manufacturers in Sweden will be found in
Jordbruksverkets föreskrift om foder
(SJVFS 2006:81). These values are based on the
European table of feedstuffs (Janssen, 1986),
where adjustments may be done according to variations in nutrient
contents, depending on the background and processing of different
feedstuffs.
The nutrient content in common and
some potential feedstuffs for poultry in Sweden is shown in Table 3 and
in the feed optimization program
Opti-kuckeliku.
Approximate figures of the use of of different feedstuffs to
different animal species may also be found in
statistics from
the Swedish board of Agriculture
(www.sjv.se). These data are based on report obligations by all
certified feed manufacturers. In total are produced about 500 milj. kg
of poultry feeds and about 75 % of the used feedstuffs are domestic.
POULTRY
DIETS SHALL BE HEAT TREATED
According to the Swedish animal feed
act, foderföreskriften, (SJVFS 2006:81) and the regulations for
salmonella control
poultry diets shall be heat treated (minimum 75°C). In practise all
broiler diets are preferred to
be
steam-pelleted, which will give this temperature effect. Also laying
hens diets normally will be heated by pelleting using a 3- or 5 mm dye,
then crushed to crumbles. Heat-treatment may be a problem on farm level,
which is one reason why most poultry diets are supplied by feed
companies. Over-heating may decrease the digestibility of the diet
implying increased excreta water content, which in turn may cause wet
litter and dirty eggs, impaired housing conditions and bird welfare.
Being grain eaters, birds have a digestive tract
designed to quickly ingest large amounts of feed, which are stored in the
crop to be 'hydrated" and 'acidified' by lactic acid secretion before
going through the proventriculus. In the proventriculus, hydrochloric
acid and pepsin and mucus secretions are increased when feed particle
size increases. The gizzard carries out feed grinding, feed impregnation
and predigestion of the feed by the secretions from the proventriculus,
as well as the regulation of feed in-flow and out-flow. The gizzard is
stimulated by a coarse feed structure, but it is a wrong idea that
poultry need grits for their digestion. More than 90 % of all broilers
in Sweden are fed whole grains, mostly wheat, from one week of age,
without any addition of grits. A small feed particle size may degenerate
the gizzard's size and function, and is suspected to give wet litter
with the same consequences as feed over-heating. Grinding with a coarse
sieve (not less than 5 mm) is to be preferred.
STARCH-RICH ENERGY FEEDSTUFFS
Different kind of cereals are the
base in poultry diets, making 50-60 and 60-70 % for layers and broilers,
respectively. In Sweden, today, mainly domestic grains are used,
preferably wheat, triticale, barley, and oat with a strong preference
for wheat. Available on the world trade market are also maize, sorghum
(durra, milo), cassava (tapioc, maniok) and rice which is scarcely used
in Sweden. Grains are considered as "energy feedstuffs" because their
protein content is comparably low, ranging from approximately 90 to 160
g/kg DM. However, in total cereals may contribute with 50 and 40 % of
the protein requirement of layers and broilers, respectively. The
energy content of cereals is related to the content of fibre,
approximately represented by specific gravity (rymdvikt).
The total content of fibre may be calculated as
dry matter (DM) minus sum of ashes, protein, fat, starch and soluble
sugar. Due to the hull fraction the variation in energy content is
higher in barely and oat than in hull-less cereals, such as wheat.
The figure below shows the relationship between specific gravity and the
content of metabolizable energy in oat, barley, rye and wheat.
At feed optimization
feed companies mainly valid cereals according to their prize in relation to their
content of
metabolizable energy (ME). Considering today's prizes of cereals
this will favour use of wheat and triticale before barley and oat. To
include e.g. oat validation has to include also other criteria
than nutrient content, which make the difference between "simple
computer users" and nutritionists.
Maize
Read more about
maize
Maize is the major energy source in poultry diets in many parts of
the world. It may be used without any special nutritional restrictions.
Due to prizes maize is little used in Sweden. In southern Sweden there
is a minor
producer using large amount of maize to his broilers
raised according to a special concept.
Read about wheat compared with maize
Wheat
Read more about
wheat
Wheat, supposing good hygienic quality, may comprise the whole cereal
part of the diet for layers as well as for broilers, and in practise,
also do so. High wheat content is a risk, however, and may cause
problems as described below. In Sweden there are several different
autumn and spring varieties of wheat with varying properties but
our knowledge about the usefulness of different varieties for poultry is
limited. Autumn wheat are characterised as "white and soft" and
considered suited for rusks and soft pastry, while spring varieties are
"red and hard" and preferably used for bakery. To here belong also
so-called durum wheats with high protein content but low protein quality.
These are mainly used for paste. On the market there are several
crossings between these original varieties, and the feed industry do
not distinguish between them. The wheat crops in Sweden consist of
about 90 % autumn wheat, implying that feed mixes mainly contain autumn
wheat.
As already mentioned poultry prefer coarse feed particles. Finely ground
wheat may be sticky like chewing gum (gluten) when mixed with water and
attach to the beak of the birds, which may cause infections and
decreased feed intake.
Wheat in large amount is reputed to induce feather pecking and
cannibalism in laying hens, which has been supported in several studies
also showing differences in sensitivity between bird genotypes. Therefore
the content of wheat in diets for layers, especially if kept in loose
housing systems, should be limited.
Wheat contains pentosans
(arabinoxylanes), which are charcterised as so-called
non-starch polysccharides (NSP).
NSPs are looked different upon in nutrition of humans (benefits) and
poultry (antinutritional substances). The usefulness of wheat,
especially for young broilers, benefits from use of enzyme preparations
with xylanase acitivities.
Read about wheat compared with maize
Barley
Read more about
barley
Baley, oat and rye, as well as wheat,
contain NSP. In barley dominates β-glucan, which is especially
antinutritional to young broilers. There are no endogenous enzymes to
metabolize NSP. The detrimental effect is an increased digesta viscosity
giving sticky droppings, which may adhere to the cloaca down during the
chicks first week of life implying constipation. The birds water
intake increases and the litter bed will be wet and sticky impairing
hygiene and housing conditions. The risk for intestine infection
with toxin producing Clostridium perfringens bacteria
increases, which may cause
necrotic enteritis (NE).
At the same time growth rate and feed efficiency will impair. These
negative effects caused by NSP may be reduced, as mentioned concerning
wheat, by adding an enzyme preparation with β-glucanase-, pentosanase-
and cellulases activities to the diet. As the birds get older the
intestinal micro-flora will adapt and may produce these enzymes why
enzyme supplementation is not as important to older birds. NE is a
"multifunctional disease" and there may also be other factors than the
diet that trigger the bacteria to produce toxins. It is recommended to
be careful by using barley to broilers. Layers may be fed up to about 30
%. Enzyme preparations are often used also to layers to prevent
problems with increased excreta water content and dirty eggs .
Oat Read
more about
oat
The hull fraction, being about 30 % of the total weight, limits the use
of oat in mash feeds, where more than 15-20 % may cause hanging in feed
silos and feed bins. Pelleting eliminates this disadvantage. The low
content of metabolizable energy in oat in relation to prize is
unfavourable in comparison with other feed grains.
In countries outside Scandinavia oat
is scarcely used in poultry diets and the unfavourable energy/cost ratio
limits the use also in Sweden. However, from a poultry point of view oat
has several positive properties mostly overlooked by the feed industry.
Excellent production performance has been shown in experiments both with
broilers and laying hens with oat comprising the whole cereal part of
the diet. The fat content is higher in oat than in any other grain. The
comparable high amount of unsaturated fatty acids does not limit the use
as it does in pig production. Oat contain more vitamins than any other
grain, among others vitamin A, E and C, which are immune
stimulating antioxidants. Oat also has its own healthy
antioxidants,
avenanthramides.
Antioxidants function in helping to maintain the stability of processed
oat products, and oat can stabilise oils and fats against rancidity. For
poultry the biological value of oat protein is higher than in other
grains. Incorporation of oats in poultry diets often show positive
effects, which may be related to oat-fibre or perhaps other "unidentified
positive factors". Thus replacing wheat with oats has been shown to
decrease/prevent feather pecking in laying hens (read
article in Swedish). It appears that at least 10 % of oat in
rations both to laying hens and broilers may never be wrong.
Rye
Read more about
Rye
Rye is scarcely used for poultry. The
reason is primary a high content of antinutritionally pentosans (NSP).
The usefulness for broilers is dramatically improved by the addition of
enzymes, but still only max. 5-10 % may be recommended.
Triticale
Read more about
Triticale
Triticale in large amount is
cultivated especially in Poland. The harvest in Sweden corresponds to
about 15 % of the harvest of autumn wheat. The prize is the same or
somewhat lower as wheat. The nutritional value and usefulness for
poultry varies with the variety but equals wheat more than rye and
Triticale may replace most of the wheat content in diets for poultry.
Rice
Read more about
Rice
Rice (paddy) contains on a weight basis about ca 20% hulls and has to be
dehulled before it could be used as human food. There are also different
grades of dehulled rice for animal purposes and supposing good hygienic
quality it is considered to be used unlimited for poultry if
necessary. The outermost part of the hull contains up to about 20 %
silica acid with sharp edges and is not suited as feed. The next
fraction consisting of pericarp-, aleuron-, germ- and part of the
endosperm layer has a high nutritional value but the hygienic stability
is low due to a high content (about 12 %) of rather unsaturated fat.
Extracted rice (-klimjöl) is therefore to be preferred.
Cassava
(yuca, manioc)
Read more about
cassava
Cassava
is a shrub that is extensively cultivated as an annual crop in tropical
and subtropical regions for its edible starchy (tapioc about 70 %)
tuberous root, a major source of carbohydrates. The crude roots are
poisonous since they contain toxic cyanogenic glucosides.är giftig
innan den på olika sätt befriats från sitt innehåll av cyanogena
glykosider. Detoxificated roots can replace cereals in diets for poultry
if its low protein content is balanced in a suitable way. As with other
feedstuffs from tropical areas care has to be taken to its hygienic
quality.
By-products from cereals
Milling by-products used for poultry are especially
wheat-middlings and wheat-bran. The protein content and quality
is higher than in the grains. The middlings is the fraction of the seed
surrounding the
endosperm.
It has a less fibre and
a
higher energy content than the bran fraction. Up to about 10 % middlings
and 5 % brans may be accepted for chickens and somewhat more to laying
hens. The development of specialized enzymes may increase the usefulness
in the future.
Malt sprouts are
obtained from malted barley by the removal of the sprouts, which may
include some of the malt hulls, other parts of the malt and foreign
material unavoidably present. It is an excellent feedstuff, which can be
included in poultry diets up to about 10 %.
Distillers dried grains
Read more about
DDGS
Distiller's Dried Grains with Solubles (DDGS) is a
co-product of the distillery industries. Most (~98%) of the DDGS comes
from plants that produce ethanol for oxygenated fuels. The remaining 1
to 2% of DDGS is produced by the alcohol beverage industry. Distiller's
dried grains with solubles are the dried residue remaining after the
starch fraction of corn or wheat is fermented with selected yeasts and
enzymes to produce ethanol and carbon dioxide. After complete
fermentation, the alcohol is removed by distillation and the remaining
fermentation residues are dried. Ethanol plants may use corn, milo,
wheat, or barley in the fermentation process, depending on geographical
location and time of the year. In Sweden today mostly winter wheat
is used, but in the future also triticale and barley may be used. In
2008 550 thousand tons of cereals, corresponding to the total poultry
feed production, giving 150 thousand tons of DDGS are counted for.
Today DDGS is mostly used for swine and ruminants. The increasing supply
and the high protein content (30-35 %) makes the product interesting
also for poultry. In North America where corn is the main source about
10 % is recommended. So far there are few experiments carried out with
wheat-DDGS to poultry, but it appears that it is comparable with corn-DDGS.
The nutrient content may vary with the grain source and the process.
The content of carbohydrates is lower,
but the proportion of antinutritional NSPs is often higher in vegetable
protein sources than in cereals, which decreases the content of ME (Table
1). As concerning cereals research is going on to develop enzyme
substances in order to increase the utilization of NSPs (read
an article).
Common protein feedstuffs for poultry are
soybean
meal,
rapeseed meal and
peas.
Potato protein and maizegluten meal are used especially in organic
production.
Lupines, if available, may also be used. There are several varieties
but sweet lupin with a low content of toxic
alkaloides
is to be preferred.
Soybean, rapeseed, flax and sunflower containing about 20, 45, 40 and 30
% fat (oil), respectively, are examples of crops mainly cultivated for
their oil properties. The residues after oil extraction are valuable
feed protein sources. By convention "meal" is the by-product after
extraction with chemical soluble (for instance hexane). The "meals"
(for example soybean- and rapeseed meal) contain about 2 % fat at the
most. Oil can also be mechanically extracted by different pressing
techniques. The residue is then named "expeller" or "cake", which
contain more fat/oil than the meal. The cakes are also good animal feed
protein sources bringing more energy but less protein to the diet
than the meals. The high content of unsaturated fatty acids in vegetable
oils is a risk for the cakes to get rancid, which has to be considered.
In diets for organic poultry only cakes can be used since processing
with chemical soluble is not allowed according to the KRAV-standards.
Protein
is built with amino acids (aa) and the quality of the protein depends
among others on the content of essential aa in relation to the animal's
requirement. If there is a 100 % agreement the protein aa composition is
said to be "ideal". Essential nutrients are nutrients that cannot
be formed by the animal itself but have to be supplied by the diet. The
most important essential aa for poultry is methionine ("the first
limiting aa"). Thereafter lysine and then threonine may be limiting.
Figure 2 shows concerning methionine and lysine the "ideality" of the
protein in some common poultry feedstuffs for laying hens.
Soybean
Read more about
soybean
Soybean protein has a comparable high
biological value for poultry. Crude
soybean contains some antinutritional substances, trypsin inhibitors
being the most important ones, which have to be neutralized by heating (toasting)
before feeding. SBM is frequently used in diets for poultry. and
supposing good hygienic quality there is no upper limit. From the hen's
point of view, as in all legumes, soybean protein is rich in lysine but
poor in methionine (Fig. 2).
Rapeseed
Read more about
rapeseed
Rapeseed is a member of the Cruciferae family and the genus Brassica.
Each rapeseed plant produces yellow flowers, which in turn produce pods.
Within the pod are tiny round seeds that are crushed to obtain rapeseed
oil. Each seed contains approximately 40% oil. The remainder of the seed
is generally processed in two steps by a pre-press solvent extraction
operation. The residue after oil extraction from oilseed rape is called
rapeseed meal (RSM). Processing of rapeseed presents, as soybean,
several by-products with varying oil content. The low-fat-meal RSM is a
very important domestic feedstuff. Today most rapeseeds are so called
double-zero (00-) varieties with low
eruic
acid and
glucosinolate
contents.
Canadian plant geneticists have been successful in developing rapeseed
cultivars, called canola, that contain negligible quantities of
glucosinolates in the seed. Meals manufactured from these cultivars are
called canola meal. However, also 00-varieties may affect the liver and
thyroid function and cause some thyroid hypertrophy if fed in high
concentration. Therefore a maximum of about 10 % is recommended in diets
for laying hens and growing/finishing broilers. In organic diets, due to
lack of other alternatives, it may be necessary to use more of certified
rapeseed cake.
Unprocessed
rapeseed and expeller may also be used. Due to the higher oil content
these sources will bring more energy to the diet. The presence of
linoleic acid is a favour.
See table.
Unprocessed rapeseed is usually crushed before mixing.
Genotypes laying brown eggs, especially crosses involving Rhode Island
Red, are normally not fed any rapeseed feed products.
The reason is that the inclusion of rapeseed meals in
the diet of brown-egg layers sometimes results in the production of eggs
with a "fishy" or off-flavour taint. This taint is due to the presence of
excess amounts of trimethyl amine (TMA) in the yolk. Deposition of TMA in
yolks by certain strains of chickens is due to the presence of an
autosomal semi dominant gene that has variable expression depending upon
various environmental factors including the inclusion rate of rapeseed
meal. Although some brown-egg strains carry this trait, white-egg
strains do not. This genetic defect reduces the synthesis of TMA oxidase
enzyme, which activity is further inhibited by the presence of
glucosinolates, leading to increased quantities of TMA in the metabolic
pool. Rapeseed contains variable levels of
sinapine, a precursor of TMA formation by the bacteria in the
intestine. Low-glucosinolate cultivars have less drastic effects on egg
taint but do not completely correct the situation. Therefore care should
be taken in feeding rapeseed or canola meals to hens that produce
brown-shelled eggs. Other feed substances with easily mobilised methyl
groups, for example
choline, may cause similar effects.
About 5-10 % of certain brown-shelled genotypes may
poduce tainted eggs. Recently, however, researchers have developed
methods to identify
"taintors",
which may be used to produce hens free of the defective gene.
The Lohmann brown genotype is since 2006 said to be free from this
problem (read
more>).
Cotton, peanut, sunflower,
linseed (flax)
Read more
about
cotton,
peanut,
sunflower,
linseed
are examples of oilseeds of
less importance for poultry in Sweden today. Cotton- and peanut meals
are exlcusively imported and hygienic critical. The occurrence of
antinutritional substances may further limit their usefulness.
Fields with sunflower are more and more becomming a feature in the
Swedish agriculture landscape due to the continuous warming up of the
climate. There are increasing interests for growing of both
sunflower and linseed, especially in organic agriculture.
Sunflower may be of most interest since it is comparatively free from
antinutritional substances. The hull/fibre part of sunflower is
high and the variation in pellets and meals depends on the processing
circumstances, which may vary between processing plants (read
more>).
Flaxseed contains a cyanide containing glucoside,
linamarin, which releases hydrogen cyanide under acidic, moist
conditions in the presence of an enzyme, linase. Under normal processing
conditions involving high temperature treatment, linase is destroyed so
that the subsequent release of hydrogen cyanide is not a problem (read
more>). Flaxseed oil contains
α-linolenic acid, belonging to the healthy
ω-3 fatty
acids. By feeding linseed, eggs
and chicken meat may be "enriched" with this acid.
Hempseed
Read more about
hempseed
Cultivation of hempseed has a long tradition in Sweden but was
prohibited for a nearly forty year period from the sixties until 2003
due to the content of cannabinoid drug substances. In 2003 it again
became authorized but circumscribed by close regulations. Only non-drug
varieties of Cannabis (the level of the drug substance CHT,
tetrahydrocannabiol, <0.2 wt%), commonly referred to as hemp, are
authorized and such crops may also get governmental financial support
(gårdsstöd).
Today, in Sweden, hemp is predominately grown for industrial (fibre)
and energy (heating pellets) purposes but there is also an interest for
oil varieties for food purposes. The fatty acid profile of hempseed oil
is unique and described to have beneficial health properties due to the
presence of essential fatty acids and a favourable
ω-6/ω-3 balance. It is well known that
hempseed is a palatable food for birds. When oil is mechanically pressed
from the seed about 10-15 % oil as well as the protein fraction (ca 30
%) remain in the residue (meal/cake). The protein is fairly rich in
essential sulphur amino acids (aa) where methionine is commonly the
first limiting aa in diets for poultry. Due to its cultivation
properties hempseed is attractive to use in organic farming. Oil is
pressed from the seed on the farm giving a residue of organic hemp seed
cake suited for organic poultry diets.
In literature, so far, there are few studies to be found, which describe
the feeding of hemp seed to poultry. A short term (four weeks) study
indicates that 200 g/kg or even more of hemp seed meal may be used. The
authors also found effects on the eggs content of essential fatty acids.
Peas
Read more about
peas
Peas are an excellent poultry feedstuff. If fed in larger amounts
white-flowered (Pisum sativum) varieties ("torsdagsärtor") are to
be preferred since they contain lower levels of antinutritional
tannins than the bluish-flowered variety (P.
arvensis) traditionally used in animal feeds. The antinutritional
effects of tannins affects for instance the digestibility of protein.
The biological value of the protein is comparably low due to low content
of sulphur amino acids, which characterizes most legume seeds. If the
diet's content of methionine is balanced by use of synthetic additives
as much as 30 % of peas may be included in diets both for layers
and growing broilers.
Lupines
Read more
about
lupines
Lupines belongs to the
legumes and have, as well as peas, a
very low content of sulphur aa.
Lupine is an interesting future organic crop
especially in organic production because it is not sensitive to the
diseases infecting peas. Lupines doesn’t need any special preceding
crop, they fixes air nitrogen and are considered to be extremely able to
utilize soil phosphorus. Plant breeding is mainly focused to blue
lupines to develop high yielding varieties lending to Swedish climate
conditions. In Denmark lupine is considered to be an important future
protein crop.
As an animal feedstuff lupine is reputed to contain antinutritional
substances, preferably
alkaloids but also tannins and hard
digestible NSP (galaktosides),
which limits its use. There are, however important differences between
varieties, and in modern varieties of sweet lupine the content of
alkaloids is said to cause little harm. The information about
recommended inclusion levels is uncertain, but 10-15 % appears to be
safe.
Potato protein
Read more about
potato protein
Potato protein is a potato product that becomes available during
the production of potato starch, using special coagulation and
separation techniques. Potato protein is a greyish-yellow, free-flowing
powder with a bulk density of 400-500 g/l. The protein content is high,
about 80 %, and the aa-pattern favourable from a poultry point of view,
remembering of fish protein
(see table).
By different reasons, for example fish allergy, some consumers demand
chicken meat produced on "vegetable" diets. Also due to high fishmeal prises potato protein may be
an alternative. Further, due to the nutrient content potato protein is very
interesting to use in organic diets, supposing the origin agrees to KRAV
standards.
Read more>
Maize gluten meal, lucerne meal and other pigment sources.
Read more about
maize gluten meal
Maize gluten is produced as a by product in the wet milling process of
maize after separation from starch. It is refined and dried in powder
form. Maize gluten is bright yellow in colour and has a characteristic
odour. This is an excellent source of protein for animals and poultry
feed, but care has to be taken concerning the hygienic quality
(salmonella, mycotoxins) since it originates from countries in hot
climates. Maize gluten meal has a high protein content, about 60 %,
characterized by a high methionine but a low lysine content. This
distinguishes maize gluten from most other vegetable feedstuffs and makes it
especially interesting to use in organic poultry diets.
Maize gluten meal is mostly used in
conventional layer diets because of its content of pigments,
xantophylls, which will bring colour to the egg yolk. Due to a voluntary
agreement Swedish layer diets do not contain synthetic pigment
supplements. In order to get a consumer attractive egg yolk colour the
diet needs to contain about 10 mg xantophylls per kg, as a minimum. This
corresponds to about 4 % of maize gluten meal giving an about 5 to
6 points-yolk according to the international
Roche standard
.
Lucerne or other kind of dried and ground "grasses" are
mainly used in layer diets as a pigment source but contributes also
with some protein. The earlier harvested the higher content and
better digested protein. The content of xantophylls is usually
positively correlated to the protein content and said to vary between 40
and 600 mg/kg. The drying and storage conditions are important
since pigments are easily destroyed by oxidation.
Algae meal is another feedstuff used as
pigment additive. A supplement with 2 mg/kg brings a deeper
colour to the yolk (see for instance
Kronäggs Guldgula). Some
other feedstuffs, such as rapeseed expeller, rapeseed meal and peas
contain small amount of pigments, about 16, 5 and 3 mg xantophyll per
kg, respectively. Other pigment sources are
paprika powder and extracts from the marigold flowers. Read more
about
yolk
pigments.
Fishmeal
Read more about
fishmeal
Fishmeal is an excellent poultry feedstuff with high protein and ME (energy)
content. On the Swedish market it originates mainly from Denmark,
Iceland or Norway. The protein content is about 70-80 % in the dry
matter. Fishmeal is today mainly used in organic poultry diets because
of the protein quality (rich in methionine), but considered to be
too expensive in conventional diets. The ME content varies with
the oil content, which may be about 10 % in meal from fat fish, for
example herring. The oil is sensitive to oxidation and may get rancid,
which can off-flavours meat and eggs. The oxidation process forms
so called
free radicals, which are considered to
be cancerogenic and involved in the aging process. It is important that
feedstuffs containing instable unsaturaed fatty acids are "stabilized"
by the precense of
antioxidants.
Fishoil may be used to "enrich" poultry products
with essential marine
ω-3-fatty
acids (see
example). ( See also
about linseed above).
EU-directive concerning presence of
dioxine in food (EC
No 2375/20) implicates restrictions of use of fish products
from certain areas.
Due to man's
over-fishing in the ocean there are
good reasons to decrease use of fish in animal feeds. Other
methionine-rich alternatives are therefore of great interest. A
potential such source is for instance
mussle meal.
Meat meal
Due to the occurrence of the "mad-cow-disease"
it is since 2001 not allowed to use any meat products in diets for food
producing animals.
FAT
Fat (oil) is commonly added to poultry diets because it
is a comparably cheap feed energy souce. The presence of fat increases
the palatability and the digestibility, which in turn increases
the utilization of fat soluble nutrients. Further fat decreases the
formation of dust and the risk of feed particles separation. These
positive properties of fat motivates a lower limit of about 2 % fat
supplementation.
Depending on its origin fats and oils contain more or less unsaturated
essential fatty acids. It is claimed
that the first 2-3 % of fat added will bring an
”extra
caloric value” corresponding to its gross
energy content to the diet.
Quality criterias are purity (dry matter content, impurities, the
portion of unsaponificable fat), chemical composition (chain length,
degree of unsaturification, portion of free fatty acids, triglyceride
structure), chemical quality and commenced decomposition (formation of
dimers,
polymeres and oxidation).
Upper inclusion level of fat in feeds depends on the fat quality and the
contribution of fat from other ingredients. A high fat content
will facilitate pelleting but decreases the durability of the pellet.
Characteristics of other ingrediants present affect pellet durability as
well. For example wheat will increase and oats decrease durabilty. As a
maximum 4-6 % fat may be added before the pelletting process, and further
2-3 % may be sprayed on the pellets afterwards, assuming needed
technicalities are available.
Animal
fat is so called
rendered or processed fat from slaughter offal from carcasses
declared fit for human consumption. There is no EU-restictions due to
BSE for use of animal fat in diets for animals. However, harmonisation of
European legislation remains a subject for attention. A few member
states are still going further than the European rules, which has lead
to serious disruption of the European market and complications of
regulations. The most imaging example is the European acceptance of the
use of animal fats in feed, where Germany has one-sided prohibited the
use of all animal fat in feed, including pig fat, poultry fat and fish
oil fit for human consumption.
The feed industry in Sweden mainly use vegetable oils, so called
”soap
stock” which is a by-product from the
processing of oil seeds.
Akofeed is such a fat.
Spent fried oils from restaurants and the food industry may also
terminate in animal feeds.
Linseed (flax) oil is interesting, as earlier mentioned, in order to
enrich meat and eggs with ω-3 α-linolenic
acid.
Pure amino acids (aa) used as
additives in poultry diets by the feed industry are
methionine ,
lysine and
threonine. To fill up to
recommended levels of these essential aa it is often cheaper to add pure
aa to the diet compared with increasing the portion of protein
feedstuffs. Another following advantage is increased biological value
due to a better balance between the essential aa. Aa supplementation may
also be the any possible way if upper limits are put on, for instance
fishmeal.
For methionine both the D- and L-form is biological active.
DL-methionine is synthetically produced . For feed purposes there is a
product containing
99% dl-methionine (DLM), but today is also often used
a hydroxy analogue (Alimet®) where the amino group on the methionine
moecule has been replaced by a hydroxy group. After being absorbed in the intestine
the hydroxy group on the molecule is said to be replaced with the
required amino group in the liver. The effect of the hydroxy analogue in comparison with dl-methionine (competition between companies) is
subject to a scientific discussion. Some studies claim that the
biological activity of Alimet is about 65 % of DLM, other studies that the
activities are equivalent on a mole basis. The variation between studies
are said to may depend on differences between the diets choline content,
the composition of the basal diet and/or the diets content of cystine.
Concerning lysine, like most other aa, only the l-form is biological
active. L-lysine is
produced by a fermentation process. Pure lysine is hygroscopic and
difficult to handle why l-lysine occurs in hydro chloride form,
L-lysine mono hydro chloride (l-lysin-HCl).
According to the
organic standards it is not allowed to
use amino acid preparations as feed additives. This complicates
formulation of nutrient balanced diets for poultry. Organic peas for
instance are less interesting since peas protein is poor of
sulphur aa (see Fig. 2). Table 4 shows different feedstuffs ranked
according to their proteins' methionine content. It
appears, as said, that peas is low-ranked. The protein content of peas
(21-22 %) is about twice as high as in cereals but nevertheless the dry
matter's methionine content is about the same.
Minerals are by convention divided in macro or micro elements. For poultry the former are considered
to be calcium, phosphorus, magnesium, sodium, potassium and
chlorine. Necessary to supplement to the diet is commonly calcium,
phosphorus and sodium. The feedstuffs normally bring more than
recommended of magnesium and potassium, meaning special supplementation
is not necessary.
The sheapest and mostly used calcium source is
limestone, calcium carbonate.
Calcium phosphates, mono- or di-, enriched from
apatite
are mostly used to satisfy recommended levels of
phosphorus. In nature phosphorus occurs in sedimentary materials (phosphorites)
to be found in large amounts in Marocco, former USSR, China, South
Africa and in Europe in Finland. The availabilty of phosphorus to the
animal in these additives is comparably high, 80-90 %. If the
content of available phosphorus in vegetable feedstuffs was such high,
extra phosphorus supplementation to poultry diets would not be necessary.
In plant cells phophorus occur mainly complex-bounded in
phytates. Phosphorus in this form is
generally not bioavailable to non-ruminant animals because they lack the
digestive enzyme, phytase, required to separate phosphorus from the
phytate molecule. Therefore it is claimed that only about 30% of the
phosphorus in plant feedstuffs is biological available, implying that a
lot of undigested phosphorus will enter the environment with the feces.
Phytase is available as a feed
additive. When using phytase supplementation un-organic phosphorus may be saved and the
pollution of the environment with phosphorus will decrease.
The cheapest feed sodium source is salt (sodium chloride). It is
considered important with a certain balance between anions and cations
in the diet implying that the chloride concentration should not exceed
the sodium content with more than about 2.5 times, which may justify use
of other sodium sources. There are narrow limits for sodium in
poultry diets, which shall be about 1.5 to 1.8 g/kg. Exceeding these
limits may cause trouble such as cannibalism (to little sodium) and high water
consumption with wet droppings (to much).
Important micro
elements added to the diet in small amounts are iodine, iron,
cobalt, cupper, selenium and zinc. The sources are for instance calcium
iodate, iron sulphate, cobalt sulphate, manganese oxide, sodium selenite,
and zinc oxide, respectively. These substances are incorporated in the
vitamin-premix or supplied separate in a trace elements premix.
Vitamins are added to all poultry
diets using a premix with for each kind of poultry recommended
amounts. The only vitamin that may be added separately is choline (choline
chloride), which is very hygroscopic and may influence storage capacity
and the activity of vitamin K. The storage properties may also impair if
mineral salts is part of the premix. To increase storage properties of
the premix a preservative antioxidation agent may also be included.
Vitamins normally included in the premix are A, D, E, B2, B3, B6,
B12, Biotin, K3, Folic acid, Pantotenic acid.
The premix base may be wheat middlings and calcium carbonate (1:1). The
concentration is adjusted so a supplement about 0,2 to 0,5 % will
deliver recommended amonunts.
ENZYME PREPARATIONS,
FEED ANTIBIOTICS AND COCCIDIOSTATS
Read more about
enzyme preparations
feed antibiotics
coccidiostats
Feed for layers do normally not
contain other subtances than what has been discussed above, but enzyme
preparations may be included by the same reasons as for broilers. The
efficacy is not so clear, however, as when used to young broilers. In
literature there are information that in adult healthy animals
enzyme-producing lactobacteria will develop, making enzyme
supplementation for decomposition of NSPs unnecessary.
In Sweden feed antibiotics were
banned 1984 and since 1998 the same decision has been taken in all
Nordic countries and till 2005 feed antibiotics were faced out in all EU
countries.
C occidiosis
is one of the most costly poultry diseases world-wide.
In chickens,
coccidiosis is a protozoan disease caused by various species of the
genus
Eimeria. The life cycle of the parasite
is complex, involves both sexual and asexual reproductive phases, and is
characterised by tremendous parasite multiplication in the cells lining
the intestines. The parasite's life cycle includes a oocyst phase in the
feces and birds will be infected when they get contact with infected
feces. When cages were introduced to laying hens in the middle of the
twentieth century the life cycle of the parasite was broken and
coccidiosis in caged layers became a minor problem. Poultry kept on
litter, especially broilers, are protected by preventive use of
anti-coccidial drugs (coccidiostats), mainly so called
ionophores, added to the diet. The use of coccidiostats is
controversail since they have been found to possess also antibacterial and
growth promoting effects and therefore act also as feed antibiotics,
hereby preventing against intestinal clostridia infections. Coccidiostats are
going to be phased out (feed antibiotics already are) in all
EU-countries during 2010-2015 and probably be replaced by vaccines. Most
laying hens are to-day vaccinated against coccidiosis during their
rearing. For broilers such replacement will increase the risk for
clostridia infections,
necrotic enteritis. This is today an
important subject for research.
Enzyme preparations as feed additives were introduced at the same time
as when feed antibiotics were phased out in Sweden. Feed antibiotics and
enzymes have complete different mode of actions. Feed antibiotics act
directly on the intestinal flora and the development of resistant
bacteria as well as transfer of cross-resistance to human pathogens have
been the main reasons for the end of use of feed antibiotics (read
more>1
>2).
Enzymes acts on the feed increasing the
availability of nutrients to the animal, which indirectly may influence
the composition of the intestinal micro-flora.
Both additives improve growth rate
and feed efficiency, but antibiotics only if the bacteria are not
resistant. Table 2 summarizes some studies where enzyme and antibiotic
supplementations have been compared.
The infection pressure of coccidiosis in Swedish broiler farms is
generally low in comparison with most other countries. This i indicated
by the fact that the same ionophore (narasin)
has been used since 1984, when feed antibiotics were banned, without any
signs of resistance.
PROBIOTICS och PREBIOTICS
Read
more about
probiotics
prebiotics
Lactic acid bacteria,
belong to the healthy intestinal micro flora preventing the prevalence
of pathogenic bacteria. How to stimulate the prevalence of a species-specific healthy intestinal micro-flora has been, and is, subject to
numerous of research in industrialized countries. Feed additives
containing living organisms used with such an aim are named probiotics
where
lactobacillus bacteria constitute a
great part of such products. Prebiotics are natural occurring substances
added with the aim to stimulate the development of a healthy intestinal
micro-flora. Such examples are different kinds of short-chained
carbohydrates, so called oligo saccharides, for instance
mannan-oligosaccharides (MOS).
The disaccharide
lactose acts in the intestinal tract by
lowering of the acidity and change of the intestinal flora to an
acidophilic type. In this way lactose is claimed to favour the
prevalence of lactic acid bacteria, helping in control of Salmonella and
Clostridia infections.
Other actual feed additives are for example
organic acids
and plant extracts, eteric oils, (example).
It is important not to forget that bacteria are bright and can
develop resistance against any substances influencing their living
terms, including organic acids and plant extracts.
Broilact
is an exampel of a probiotic product used to protect birds
to salmonella infections, when there appear to be such a risk. Resistance to
the infection develops with the establishment of an adult type of
intestinal microflora. This progress can be accelerated by exposure of
newly-hatched chicks to caecal or faecal bacterial flora from adult
fowls. The phenomenon by which the normal intestinal microflora protects
the host against invading pathogens is called competitive exclusion (CE)
or the "Nurmi concept". Protection depends upon the administration of
viable anaerobic bacteria, but the mechanism of CE is still poorly
understood. The two most often cited mechanisms in connection with CE
are: production of volatile fatty acids in the caeca, and occupation of
sites on the mucosa.
A
lot of research has been focused to probiotic substances without showing
any general distinct positive effects on growth rate and feed
efficiency similar to those achieved with "the old" feed antibiotics.
Possible effects vary from trial to trial and the use of probiotics may
be regarded as a complement to other measures.
A recent launched probioticum is
"Biacton",
a microbial feed additive based on a strain of Lactobacillus farciminis
isolated from the intestine of a healthy pig. Most interesting with this
product is the effect against clostridia bacteria, which has been
reported.
REFERENSER
Damme, K. and Peganova,
S. 2006. Einzats von
getrockneter Weizenschlempe. Legehennefütterung. Deutschen
Geflügelwirtschaft, 2006:18, 23-30.
Danner E.E. and Bessei W.
(2002) Effectiveness of liquid DL-methionine hydroxy analogue-free acid
(DL-MHA-FA) compared to DL-methionine on performance of laying hens.
Archiv für Geflügelkunde 66, 97-10
Dimberg, L.
2004. Antioxidanter i havre: Halten avenantramider kan påverkas både
före och efter skörd. Fakta Jordbruk 2004:1, SLU, 750 07 Uppsala.
http://www2.slu.se/forskning/fakta/faktajordbruk/pdf04/Jo04-01.pdf,
20050831.
Jansen I.W.M.M.A.
1986. European
table of energy values for poultry. Spelderholt center for poultry
research and extension. 7361 D.A. Beckbergen, Holland.
Jordbruksverket 2005. Statens jordbruksverks föreskrifter (SJVFS
1993:177) om foder
Ministry of
Agriculture, 1998. The Swedish model of animal production. Information
based on presentations given at a seminar held in Stockholm 3-4
September 1998.
http://www.keepantibioticsworking.com/library/uploadedfiles/Swedish_Model_of_Animal_Production_The.pdf,
18 sept. 2007
SJVFS 2005:33. Saknr M 39
Schutte, J.B., Van
Kempen, G.J.M. and Hamer, R.J. 1990. Possibilities to improve the
utilization of of feed ingredients rich in non-starch polysaccharides
for poultry. In. Proceedings VIII European Poultry Conference, pp
128-135. Feria de Barcelona Avda. Reina M. Cristina, s/n.
University of Minnesota. Poultry Nutrition,
http://www.ansci.umn.edu/poultry/resources/nutrition.htm,
2005-09-19
Åman, P. 1987.
Analys och kemisk sammansättning av svensk spannmål. Fakta. Husdjur nr
3, SLU.
|
|
|
|
Carbohydrates |
Met. energy |
|
|
Pro-tein |
Fat |
Total |
Starch
+suger |
NSP |
MJ/kg DM |
|
Maize |
10.3 |
4.6 |
83 |
74 |
9 |
15.9 |
|
Wheat1 |
12.8 |
2.4 |
77 |
68 |
9 |
14.7 |
|
Barley1 |
10.8 |
3.0 |
77 |
62 |
15 |
13.6 |
|
Oats1 |
11.6 |
5.7 |
66 |
46 |
20 |
12.3 |
|
Wheat
middlings |
17.0 |
3.4 |
62 |
18 |
44 |
7.8 |
|
Field beans |
31.7 |
1.7 |
60 |
43 |
17 |
11.7 |
|
Peas |
26 |
1.7 |
58 |
40 |
18 |
12.6 |
|
Lupins |
41 |
5.5 |
44 |
7 |
|
FEEDSTUFFS
AND DIETS FOR LAYING HENS 