Diary of a Poultry Farmer: For yellow-yolked eggs, try using this common weed

Friday January 13 2017

Yellow egg yolk.

Yellow egg yolk. Leaf meal offers a good alternative for farmers who do not want to use nature identical synthetic beta carotene to make egg yolk yellow. FILE PHOTO | NATION MEDIA GROUP 

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You probably recall the ‘eureka moments’ I had last year after weeks of struggling to get the yolk of my eggs as yellow as possible to meet customer demands.

Just when I thought I had solved the mystery once and for all, I received additional insights from Dr Steve Franzel, a leading researcher at World Agroforestry Centre (ICRAF) who has done extensive research on the subject in Tanga, Tanzania.

“My own research and that of Kenya Agricultural and Livestock Research scientists revealed that feeding leaf meal (calliandra or leucaena) to the hens improved the colour of the egg yolk from white to deep orange colour,” he wrote.

Before I talk about the leaf meal (Leucaena leucocephala), I will take you back to where my experiments to get yellow-yolk started.

At first, I had tried to give the hens grass and cabbages because they were the cheapest ‘greens’ I could find, but the results were disappointing.

I then consulted Dr Silas Obukosia, an agricultural biotechnologist, who explained the reason for the poor results.

“Beta carotene,” he intimated, “Is the substance that contributes to the yellow-orange colour of different fruits and vegetables. The pigment is found in highest concentrations in sweet potatoes, carrots and green leafy vegetables like spinach and sukuma wiki.”

Armed with the information, I tried a few more experiments. First, I crushed some carrots in a blender, mixed with water and gave to some few birds.


After five days, Cleophas called to inform me that the yolk had turned yellow (Seeds of Gold, April 16, 2016).

Next, I tried a supplemental carotenoid known as nature – identical yellow and red carotenoids that are normally added to commercial feeds to augment the colour of the egg yolk.

It worked wonders but not after I had tried different quantities. I learnt that you need to add between 90 and 100g of the supplemental carotenoid for every 70kg of feeds to get the yellow colour (Seeds of Gold, June 25, 2016).

Another option was using yellow maize instead of white to formulate the feeds. Alfafa (lucerne) when fed to the birds also augments the colour of the yolk.

However, leaf meal was new to me and I sought more information from Dr Franzel.

He explained that leaf meal, either calliandra or leucaena varieties, is an efficient contributor of pigmentation for egg yolk.

“Poultry farmers feeding leaf meal at between 2 per cent and 4 per cent of the ration can expect good results,” he told me.

In addition, he said that it can be used in dairy rations to provide protein, energy and to increase milk production. As a dairy cow supplement, one can mix maize bran, cottonseed cake and leucaena leaf meal in a 3:2:1 ratio.

From my research, I had read that unlike calliandra, leucaena was an aggressive and invasive shrub that could easily become a fastidious weed.


Dr Franzel had some advice. “Leucaena shrub becomes a problematic weed if it is allowed to grow big enough to start bearing seeds that then sprout. Prune it as often as necessary.”

Another thing I was interested to know from Dr Franzel was why, despite the advantages, the weed was not being processed and marketed as an animal mineral feed supplement.

First, he said that the plant is very bulky and requires to be processed by drying and crushing the leaf meal, and then using simple machinery to grind it into a powder or pellets that can then be mixed into animal feeds.

Second, he said that unlike in Asia where it is grown as a crop, in East Africa, it is mainly collected from the wild.

“Producing leucaena as a crop has higher returns than maize and farmers should be assisted on the farms or on the boundary as a live fence,” he said.

Leaf meal, therefore, offers a good alternative for farmers who do not want to use nature identical synthetic beta carotene to make egg yolk yellow. The shrub can be grown along the fence if space is a problem. 



Esther, Bondo: How much can a simple unit for 500 birds cost?

If you are using wood for the frame, iron sheets for the walls and roof, you are looking at about Sh100,000 to Sh120,000.

Remember that for the front, use iron sheets halfway and cover the upper part with a wire mesh and net for ventilation.

Now, if you are in a rural setting, you can use mud for the walls and this can lower the cost drastically. I have built a chicken coop in my rural home using mud and sticks.

What added the cost was cementing the floors and walls. The only thing you need to be careful about is dealing with termites.

Gilbert Mutai:I read your answer to Derosin Busuru’s request on knowing the cost of building a chicken house. I wasn’t able to understand. 

On the issue of housing and plans, find as noted above. Further, different types of materials like wood – cider, grevillea and cypress cost differently.

In fact, even two hardwares next to each other can sell the same items twice as much as the other.

Also, if you are say in Nairobi, Mombasa or Kisumu, these items will cost differently. If you are in Nairobi, feel free to visit my farm.

Kelvin Kwatch, Maseno University: I am pleased with how you have been tackling  poultry issues. I have been rearing Kienyeji chickens and they are doing well but I have a  dream of expanding my farm but I have a challenge with capital.

I agree with you that agriculture is the only way to improve household incomes in rural areas and also to create employment.

One option of raising capital is to team up with others and develop a joint proposal.

Please send me an email for a few ideas you may wish to consider.