The chickens are laying well again, despite the exceptionally cold weather for this time of year. I have been providing them with an additional handful of mixed corn to keep them warm and started to think about yolk colour.
It seems we choose our food on the way it looks, more than the way it tastes these days. Our egg yolks are required to be a certain shade of yellow. Egg yolks that are too light don’t make it to the shops and it is for this reason that commercial feed rations contain natural, or often synthetic pigments to ensure they produce egg yolks with a good colour.
There are of course perfectly good natural sources of yolk pigments that can be fed to hens and it is useful to know what will change the colour of yolks.
You will often see photos where people take a free range egg produced at home and compare the yolk colour to that of a shop bought egg and comment on how much better the free range egg is. This is simply the diet of our free range hens having access to more feeds that contain xanthophyll.
The most notable pigment comes from maize. Maize can come from ‘corn on the cob’ that we sometimes feed to our chickens but usually, it’s dried, cracked maize that is fed in mixed corn. As well as colouring egg yolks, it will also colour the skin and turn white feathers ‘brassy’ so should be avoided in white breeds that are going to be taken to a show. I’m sure you’ve seen the skin colour of a ‘corn fed’ table chicken and this is usually from maize being in the diet.
Maize is very useful in the diet on cold winter days since it contains the most energy of all cereal grains (it is high in Carbohydrate) but contains little else in the way of nutrients and like other grains, the protein quality is relatively poor. It should normally only be fed in small quantities though. I give my hens a handful of mixed corn each which contains a small percentage of cracked maize in the late afternoon and I double this quantity in freezing weather. Hens will put on too much fat if they are over-fed with maize and are not burning the extra energy off (which they do to keep warm in cold weather). Overweight hens cannot pass eggs easily which makes them prone to prolapse. Often they will simply stop laying, leading to the saying “Fat hens don’t lay eggs”.
Hens grazing on good quality grass and other greens will also have good coloured yolks. Nutritionally, grass is at its best in the spring and early summer and contains a high level of protein as well as xanthophyll. Grass must be kept short, no longer than 4″ long. Long grass is woody and useless nutritionally. Young geese for example can starve if grass is not kept short. Carrots contain a lot of carotene but despite popular belief that they will help egg yolk colour, they will not.
Red or Green Yolks
If a hen’s diet contains paprika, it will cause yolks to turn orange to red in colour however capsicum (peppers) don’t have this effect. Green yolks in a free range setup are usually as a result of an imbalance of nutrients. Typically, this is caused by a diet being low in protein and a hen picking up pennycress, clover and shepherd’s-purse from the pasture. Young acorns can also cause Olive green egg yolks yet ripe acorns don’t have the same effect!