Factors affecting yolk colour of poultry eggs
The ideal yolk colour doesn’t exist, because it is heavily influenced by consumer preference.
Asian consumers like an orange to red yolk, European consumers prefer golden yellow: as a producer you can tune your birds to the right yolk colour by adding natural raw materials to the layer feed such as yellow maize, Lucerne, dried vegetables or other plant materials. For example, grass meal will give a darker yolk colour and feeding most other grains will actually make the yolk lighter. A golden yolk is determined by 2 compontents: a yellow base color and red to deepen it. Lutein and zeaxanthin are the carotenoids that provide yellow, canthaxanthin provides red. Additives can be added to the feed accordingly, but don’t always have the desired effect.
A golden yolk is determined by 2 compontents, a yellow base color and red to deepen it. Photo: Roodbont
7 problems with pigmentation and actions
Pigment breakdown in feed: Store additives and premixes in airtight containers, in a cool place and never in sunlight. Do not store them too long.
Insufficient carotenoids in the feed: The amount of carotenoids might be insufficient. That can certainly be the case if you are using natural sources, in which concentrations can vary. Added pigments are easier to manage.
Insufficient pigment reserve: Flocks that start coming into lay can have insufficient pigment reserves. Begin feeding pigment 2 to 3 weeks before the flock starts laying.
Oxidising substances or pigment antagonists in the feed: Some substances may negate the effect of pigments, e.g. barley and triticale in the feed. In such cases, you have to add higher concentrations of pigment in the feed. If oxidants are the culprit, add antioxidants.
Poor feed mixing: Always make a premix of the pigments before finally mixing them into the feed. This method produces better mixing results.
Poor storage conditions: Keep feed cool and dry. Storing feed in damp and/or warm conditions reduces the effectiveness of pigments.
Rough feed handling or transport: Handle feed carefully to ensure the different components do not separate. Take special care to check this if you use augers in your feed system.
Courtesy-Indbro
