20 Carotenoids in Aviculture
523
20.5 Carotenoids in Poultry Nutrition
20.5.1 Egg Yolk Pigmentation
Colour is an important factor affecting consumer choice of foods through sensory
evaluation. In many countries of the world, golden colour of yolks is preferred
because yolk colouration has been traditionally associated with good health. There
are three major carotenoids commercially used in poultry production, including
• Lutein
• Zeaxanthin
• Canthaxanthin
In addition, citranaxanthin, apo-carotene-ester and capsanthin are used to maintain attractive egg colouration. Main sources of feed-derived carotenoids include
yellow corn, corn gluten and distillers’ grains providing a mixture of lutein and
zeaxanthin; as well as alfalfa and its concentrate, providing mainly lutein. Natureidentical or nature-extracted yellow carotenoids are obtained from marigold (lutein)
or red carotenoids from paprika (capsanthin and capsorubin with some lutein and
zeaxanthin). Furthermore, apo–ester, canthaxanthin and citranaxanthin are the main
commercial sources of nature-identical carotenoids for poultry industry. It seems
likely that apo-carotene-ester and canthaxanthin (CX) are most effectively deposited
in egg yolk yellow (about 55%) and red (about 40%) carotenoids (Surai 2002). In
our experiments CX was added to the diet of the broiler breeder birds at 0, 3, 6, 12,
24 mg/kg and its concentration in the egg yolk was shown to be 0, 7.48, 14.75, 28.89
and 56.99 μg/g, respectively (Surai et al. 2003). Interestingly, those egg yolks from
breeders supplemented with two highest doses of canthaxanthin were deeply red in
colour, reflecting low level of yellow carotenoids provided by basic diet. Indeed, in
order to have an optimal (orange) colouration of the egg yolk various combinations
of yellow and red carotenoids are commercially used. Generally, commercial technology of egg yolk colouration has been well developed and are widely used. Since
organic egg production systems do not allow synthetic carotenoids to the feed alfalfa
meal and its extract found their way into organic egg production. Interestingly, alfalfa
meal was widely used 30–50 years ago in poultry diets and special technologies of
its stabilisation by antioxidants to prevent carotenoid oxidation during meal storage
have been developed and effectively used in countries of former USSR (Zhedek et al.
1996). With organic production demand for natural sources of colouring agents for
egg yolk those old technologies can be used. Indeed, “All new existed in the past”.
523
20.5 Carotenoids in Poultry Nutrition
20.5.1 Egg Yolk Pigmentation
Colour is an important factor affecting consumer choice of foods through sensory
evaluation. In many countries of the world, golden colour of yolks is preferred
because yolk colouration has been traditionally associated with good health. There
are three major carotenoids commercially used in poultry production, including
• Lutein
• Zeaxanthin
• Canthaxanthin
In addition, citranaxanthin, apo-carotene-ester and capsanthin are used to maintain attractive egg colouration. Main sources of feed-derived carotenoids include
yellow corn, corn gluten and distillers’ grains providing a mixture of lutein and
zeaxanthin; as well as alfalfa and its concentrate, providing mainly lutein. Natureidentical or nature-extracted yellow carotenoids are obtained from marigold (lutein)
or red carotenoids from paprika (capsanthin and capsorubin with some lutein and
zeaxanthin). Furthermore, apo–ester, canthaxanthin and citranaxanthin are the main
commercial sources of nature-identical carotenoids for poultry industry. It seems
likely that apo-carotene-ester and canthaxanthin (CX) are most effectively deposited
in egg yolk yellow (about 55%) and red (about 40%) carotenoids (Surai 2002). In
our experiments CX was added to the diet of the broiler breeder birds at 0, 3, 6, 12,
24 mg/kg and its concentration in the egg yolk was shown to be 0, 7.48, 14.75, 28.89
and 56.99 μg/g, respectively (Surai et al. 2003). Interestingly, those egg yolks from
breeders supplemented with two highest doses of canthaxanthin were deeply red in
colour, reflecting low level of yellow carotenoids provided by basic diet. Indeed, in
order to have an optimal (orange) colouration of the egg yolk various combinations
of yellow and red carotenoids are commercially used. Generally, commercial technology of egg yolk colouration has been well developed and are widely used. Since
organic egg production systems do not allow synthetic carotenoids to the feed alfalfa
meal and its extract found their way into organic egg production. Interestingly, alfalfa
meal was widely used 30–50 years ago in poultry diets and special technologies of
its stabilisation by antioxidants to prevent carotenoid oxidation during meal storage
have been developed and effectively used in countries of former USSR (Zhedek et al.
1996). With organic production demand for natural sources of colouring agents for
egg yolk those old technologies can be used. Indeed, “All new existed in the past”.