Welfare advice with poultry vet Victoria Roberts
QI have Marans and Black Rocks, and recently added a six month old Amber Star and a Bluebell. The latter two have been laying eggs with slightly bluey/ green tinged yolks. Why would this be, especially as they are being fed the same as the other birds? They free-range in my garden.
If they are free-ranging the two new ones could have found a plant they are sharing which would colour the yolk. We do know that acorn consumption will provide a dark line around the yolk, but other strange colours have not yet been proven to come from specific plants (there’s a project for someone). The orange colour we expect of yolks from free-ranging hens is obtained from dark green plants – commercial feed tends to have this canthaxanthin colourant added (e.g. marigold petals provide a good and consistent source) since pale yolks are not considered as healthy. There is some truth in this as there are less omega 3s in pale yolks. The new hens may have had an incident in their rearing to cause the odd colouring; maybe you should contact your supplier to ask husbandry questions?