I have previously recounted how my search for yellow–yolked eggs finally bore fruit after I gave my chickens carrots and green leafy vegetables.
However, despite this success, I did not give up and I have been trying other ways as I seek to find the easiest and most economical method.
To revisit my journey, at first, I tried giving the hens grass and cabbages but the results were negative. I then consulted Dr Silas Obukosia, an agricultural biotechnologist, who informed me that the two don’t contain any beta-Carotene, the substance that contributes to the orange colour of many different fruits and vegetables.
Instead, he said that although the yellowing substance can be found in fruits, vegetables and whole grains, the highest sources of the beta-Carotene foods are sweet potatoes, carrots and dark green leafy vegetables like spinach and sukuma wiki, in that order.
I crushed some carrots in a blender and put in the chickens drinking water. After five days, I had a ‘eureka moment’ when the egg-yolk turned yellow.
Now, after I shared that story, I received over 30 emails from readers. One reader, Kennedy Ogango, a feeds manufacturer from Nakuru County, told me about supplemental carotenoids known as nature-identical yellow and red carotenoids that are normally added to commercial feeds to augment the colour of the egg yolk.
Well, I must admit that through writing this diary, readers share information that would ordinarily be classified as “business secrets”.
Ogango had cautioned me that many farmers using the recommended ratio of 0.5kg of the pigmented nature identical carotenoids per tonne of feeds (35g per 70kg of feed), were not getting satisfactory results.
NOT ADVISABLE TO BUY BETA-CAROTENE IN SMALL QUANTITIES
“Many have complained that some of these carotenoids in the market do not contain sufficient amounts of the minerals,” he lamented. I wondered what could be the reason for this.
Since I needed to find the answer, I instructed Cleopas to source around for it. I was delighted when after two days, he called to inform me that he had found one retailer for this substance somewhere in Syokimau, on the outskirts of Nairobi.
“What is the price?” I asked. “A bag of 25kg retails for Sh12,500,” he said. However, the seller was not willing to sell in small quantities.
You will soon understand why buying the supplemental beta-Carotene in small quantities is inadvisable.
Right away, I knew I had a problem. You see, I make about a tonne of feeds fortnightly. That means that with 25kg, I would need to make 50 tonnes of feeds. It would take me two years to use up the 25kg.
I called Dr Obukosia to find out how long I could store the beta-Carotene for later use. He had some bad news.
“Beta-Carotene is a very unstable chemical and if you store if for long, it deteriorates,” he said. At least I had one clue why many farmers who rely on commercial feeds do not get satisfactory egg-yolk colour—the carotenoid content in the ingredients of poultry feeds is weakened with time.
I asked Cleopas to source around for a seller who would be willing to sell us about 2kg. Luckily, he found one in town, but the price was Sh1,200 per kilo.
I decided to take a leap of faith and bought 2kg. I then instructed Cleopas to mix 35g in 70kg of layers mash, isolate a few birds and feed them. I was disappointed.
After one week, he informed me there was no change in yolk colour. Was I sold an expired product? My consolation was this: Unless you are very good with the mixing, blending 35g in 70kg and expecting “results” is like looking for a needle in a haystack.
An idea came to my mind. I recalled the experiments in my biochemistry class using a so-called “titration technique”.
Simply put, this is a technique where a solution of known concentration (titrant) is used to determine the concentration of an unknown solution (analyte) until you get a “neutralisation reaction”, which is often indicated by a colour change.
That is exactly what I did. I asked Cleopas to increase the amount of beta-Carotene to 70g per 70kg of layers mash.
There was a slight colour change in the yolks. However, after increasing to 100g per 70kg of layers mash, the yolk was almost turning orange in colour.
At this point, I figured that anything between 90 and 100g of supplemental carotenoids for every 70kg of feeds is sufficient to produce yellow-yolked eggs.
Please, however, note that yellow-yolked eggs are not of better nutritive value although consumers prefer them to pale ones.
Another thing an agronomist told me is that although using nature-identical beta-carotenoids is not harmful to human health, there are natural ways to produce yellow-yolked eggs such as feeding birds on yellow maize and alfafa (lucerne).
I have also experimented with green leafy vegetables like sukuma wiki and spinach with great success.
In my next experiment, I intend to try sweet potatoes, one of the highest natural sources of beta-Carotene.