When eggs are too big to fit in incubator tray - Daily Nation

Diary of a poultry farmer: When eggs are too big to fit in incubator tray

Saturday August 11 2018

The younger a hen starts egg production, the smaller their eggs will be during her first year of life.

Eggs arranged on top of each other. The younger a hen starts egg production, the smaller their eggs will be during her first year of life and the start of egg production can be delayed by providing less than 10 hours or less of light each day from week five to 19 of age. PHOTO | AFP 

By SUBIRI OBWOGO
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“The eggs cannot fit into the tray,” the worker told me, his voice showing some worry.

I could hear the egg incubator beeping in the background indicating that either the humidity or the temperature readings were out of range.

“Is the door open?” I asked before requesting him to hang up so that I can call him back.

“I’ll be there in the next 30 minutes,” I said.

When I got to the farm, Ben, my new worker, showed me the eggs. I asked him to weigh them using a digital scale.

I’ve dealt with oversized and undersize eggs before but this was different because I also rear parent stock to sell fertile eggs and hatch chicks for sell. But more about that in a moment.

In the past, I mentioned that small eggs fetch lower prices and if you want to maximise returns, increase the size of eggs.

In fact, the smallest egg sizes you’re likely to find in the supermarkets shelves are medium-sized that weigh at least 50g. The size of an egg is determined strictly by weighing.

The largest egg (jumbo) weighs about 70g while the smallest (a pewee) 35g. In between, you’ve the extra-large, large, medium and small eggs weighing 64, 59, 50 and 43g respectively.

What the experts told me then was that the breed, age and type of diet will determine the size of eggs in a flock (Seeds of Gold, April 30, 2016).

“Bigger hens produce larger eggs than smaller ones,” I was told. I confirmed this from my own observations. The size of eggs from Kari Improved Kienyeji chickens, which I rear cannot be compared to those from free-ranged kienyeji chickens.

There’s also a direct connection between the body size of the hens and the breed. “Hens with bigger and longer legs tend to lay huge eggs. Big breeds like the Leghorns, therefore, tend to lay larger than average size eggs”.

Another thing I was told was that the type of diet also determines the size of egg.

FACTORS TO BEAR IN MIND

“Feeding layers mash high in protein (18-20 per cent) in the first couple of months of production increases egg size.” However, I was cautioned that once the flock reaches maximum egg production, high protein diets no longer promote large increases in egg size.

“After 36 weeks of age, feeding rations with 15 to 17 per cent protein content will help slow increases in egg size,” Dr Silas Obukosia, the agricultural biotechnologist said.

The size of the skeleton also matters. “Feeding a high protein ration to chicks before 10 weeks of age is the main factor influencing skeletal size of a particular breed of hen.”

Now after weighing the eggs in question, I realised that the large ones that couldn’t fit in the incubator’s cubic chambers ranged between 69g and 85g, with an average of 75g. The smaller ones were averaged 25g.

As a matter of fact, besides the breed, age and diet, there are other factors to bear in mind especially if you’re rearing breeding stock like me.

I read that light management programme for hens will determine the age at which hens start laying eggs, the number of eggs, their size and consistency of laying throughout life.

“The younger a hen starts egg production, the smaller their eggs will be during her first year of life and the start of egg production can be delayed by providing less than 10 hours or less of light each day from week five to 19 of age.”

In fact, decreasing the daily hours of light at any time after 10 weeks of age will also delay the start of egg production.
Here’s my dilemma. A year ago, when I tried to design a light management programme for my layers, one difficulty I had was making the coop as dark as possible (Seeds of Gold, July 29, 2017).

You’ll also recall when I shared my 11-point guide to select and handle eggs for incubating that it’s inadvisable to incubate very small or very large eggs (see All you need to know about egg incubation available online)

In the end, I was left with no alternative but to consume the extra-sized and small-sized eggs.