A local agricultural innovator developed a kit for poultry farmers to use in checking egg fertility and assess progress during incubation. Called ‘Candling box,’ farmers can use the kit to know which hens lay eggs that can’t hatch, and are due for culling.

According to Mr Geoffrey Kago, the inventor, he is selling about 50 of the candlers a month compared to 10 this time last year. He came up with the concept after he encountered the challenges in his own poultry farming in selecting between eggs to put into the incubator and those to leave out. The candler helps “assess the defects in an egg and check its progress, like nutrition,” says Mr Kago.

The candler is rectangular in shape and slightly bigger than a brick and has a hole on one side designed to fit the pointed side of the egg.

Inside, it is hollow with a lighting fixture. To check the egg’s condition, the farmer places its pointed side in the hole and lights the candler in a dark room.

If the farmer notices the air sac in the less pointed side is sagging and big, then it’s a sign the egg has stayed for too long and thus dehydrated. Therefore, it can’t be placed in an incubator to hatch, since it has lost 15 per cent of the water in it.

Ideally, according to Mr Kago, to select an egg for hatching it must be less than seven days old. “As the egg ages, the air space becomes bigger,” he says. Where the farmer sees two yolks in an egg, it is also unsuitable for incubation.

Mr Kago also advises farmers to check the outward physical appearance of eggs and ensure that they are of uniform colour and size for that particular bird breed.

Eggs with blotches, wrinkles, bumps or multiple colours may not hatch if incubated, as it’s a sign of deficient nutrients in the hen that laid the eggs.

Besides checking the egg before it’s placed in the incubator, the candler helps farmers to gauge the progress of eggs waiting to hatch in the incubator. Thus, a farmer is able to isolate spoilt eggs and tell the number of chicks one is likely to get.

By checking the progress of eggs, a farmer could also tell which of the hens lay fertile eggs, as well as which cocks are old and inactive with the hens. That way, farmers can pick chicken for slaughter or sale and retain the most productive.

Mr Kago advises poultry farmers that prior to checking the eggs in the incubator, they should wash their hands to avoid contaminating eggs.

When an egg is progressing to hatch, the candler shows a consistent formation of a network of blood veins from day 10 to day 18, a silhouette chick image is visible. “It’s the growth of an embryo,” he says.

From his base in Gitaru on the Nairobi-Nakuru highway, he sells a candler with lighting system for Sh1,000 and one without for Sh500. The one without light sees farmers use ordinary torch to examine their eggs. Mr Kago says the demand for his candlers is propelled by the need for new innovative egg incubators that he also invented and sells. It can check eggs for ducks, turkeys and guinea fowls, and hens.