FIVE THINGS YOU’VE ALWAYS wanted to know about the Chicken and the Egg but were too afraid to ask. Or too embarrassed. Or too not bothered, preferring to leave them as one of life’s many unsolved riddles. Well, livingmsia has taken the initiative to “eggs”-plore some “eggs”-traordinary avenues for answers and here are the ‘eggs”-planations:
A: Because chickens or hens were born to lay eggs, with or without a rooster! Some chickens will lay more, some less, or more regularly like everyday as opposed to once or twice a week but all will lay eggs on schedule, like clockwork, with or without the male equation called the rooster.
Of course, by “all”, we mean normal healthy chickens not affected by deformities, malnutrition, illness and disease. Some hens do not lay eggs ever because of underdeveloped pelvises and other genetic anomalies.
So why do chickens lay eggs regardless? Because nature made them this way. Much like female humans, a female chick has all the eggs she will ever lay in her lifetime present inside her body the moment she is born. These are the thousands of tiny ova or undeveloped yolks lodged inside her ovary within her reproductive system.
Once she reaches maturity (by around 20 weeks, some earlier, some later) the ovum will be released into a tube called the oviduct and begin its journey of development into a full-fledged egg. In 24 to 25 hours from the start of the release of the ovum, an egg will be laid!
Eggs are actually the discharge of unfertilised ova from the body. The body or DNA compels the chicken to do so. The human equivalent of this process can be likened to ─ as a blog called Fits and Starts describes it ─ menstruation. Yes, menstruation ─ like our involuntary act of expelling our unfertilised eggs, only we don’t eject them as hardshelled eggs. The chicken laying its unfertilised eggs as a matter of “must!” can therefore be said to be the direct equivalent of the human menstrual cycle.
The reproductive organs of a productive hen is thus like a factory production line for eggs. At any given time, she will have several eggs in various stages of development going on, with the eggs most recently discharged from the ovary being tiny yolks and the ones further down the oviduct getting larger and more complete, covered by a shell and ready to be popped out when it reaches her exit point or vent! Quite amazing!
A: Some breeds such as the Lohmann Brown and others start laying eggs early in life, as early as 14 weeks old and go on their relentless egg production for the next two years. With the chicken aging, production declines but some layers will still go on regardless, laying egg after egg without a slowdown for more than two years.
The egg laying mechanism in a chicken is triggered by daylight, and not the presence of a rooster, sex or sperm. Which is why some chicken farms make sure their lights are switched on early to simulate long daylight hours to encourage production. If you’re thinking of opening a chicken farm, get up early and switch on the lights because chickens never lay eggs in the dark!
Q: How are eggs fertilised or more to the point, how do chickens copulate?
A: We wouldn’t even call it copulation because there’s hardly any sex in the act. First of all, the rooster has to struggle with the fact that all of his reproductive organs are inside his body ─ uh huh, no dangly bits to stick anywhere so he’s got a difficult job. But he does produce semen from his papilla ( a little bump-like protrusion not at all like a penis but more like a large pimple) inside his cloaca or vent located under his tail plume.
The hen too has a cloaca (or vent), the same place where her egg exits from. The cloaca is the chicken’s one and only external opening, used for egg laying (for hens) or sperm depositing (for roosters) and elimination.
To mate, the rooster simply stands on top of the hen, stands on her back actually, then lowers his cloaka to meet her upraised cloaca as she squats and spreads her wings somewhat for balance. Their cloacas meet, (called the Cloaca Kiss for obvious reasons) and in a split second, he transfers his sperm packet to her.
And that’s all there is to chicken copulation. Both hen and rooster then say “good day” to each other and go about their separate ways.
Sperm stays alive in the hen for as long as two weeks. If sperm is present, the yolk will be fertilised before the albumen (egg white) is deposited.
No eggs are fertilised after they are laid.
Q: What is the egg formation process like in the hen?
A: From the moment her ovum (or little yolk as tiny as a follicle) leaves the ovary, it takes a chicken about 24 to 25 hours approximately to form and lay a brand new egg.
With the ovum travelling down the duct, a membrane will form around the yolk to hold it in place in the centre of the soon-to-be formed shell. This process takes about 15 minutes. Further down the oviduct, at the magnum, albumen will be deposited around the yolk, taking about an hour.
If sperm is present, the yolk will be fertilised before the albumen is deposited, where the chick embryo will start developing.
But regardless of whether there is an embryo or not, the egg will keep on travelling until it reaches the isthmus where another membrane will wrap around the embryo/yolk and albumen before it reaches the last step where the shell is formed around the egg. This is the last and longest stage of egg formation. The process of calcification and mineralisation will take about 20 hours where the entire egg, all shelled up, will reach the vent or cloaca where it will pop out soon after.
Q: Which breed of chicken are the best layers in Malaysia?
A: Malaysian egg farms use hybrid chickens to lay the best eggs. The two breeds most widely used are the Lohmann Brown and the Hisex Brown. These two are prolific layers, laying up to 300 eggs a year and satisfactorily meeting our chicken farm’s production quota.
Of the two breeds, the Lohmann Brown is slightly superior (both as a layer and as a chicken too!) in that she starts egg production earlier than other chickens ─ at 14 as opposed to 20-24 weeks. She lays a sturdy, large brown egg everyday without fail, is easy-going socially and can adapt to different environments. The Lohmann Brown is therefore the darling of the egg farms as it can be raised in a cage or free range. It also exhibits high resistance to diseases.
The Hisex Brown is also a good layer. She produces medium-sized brown eggs known for their nice, strong shells. Her egg production is only slightly behind the Lohmann Brown.
These two breeds are replacements for the White Leghorns, the layers of yesteryears, which produced white eggs but had low yields.
Over on the Kampung Chicken front, recently, UPM in Serdang announced the development of the Akar Putra, an “accidental” new hybrid of chicken that is proving to be superior to our current Ayam Kampung. The Akar Putra can lay up to 200 eggs a year or four times as many as its village cousins and this says a lot about meeting consumption demands.
We use the word “accidental” in the making of this breed because one half of the Akar Putra was actually the wild red jungle fowl that flew into UPM’s Ayam Kampung breeding farm one night and had a nice long tryst with the inmates there. Naughty naughty!
But the results absolve the act completely.
Their cross-bred offsprings were then raised and allowed to reproduce and the outcome today is the bigger-bodied, stronger and taller Akar Putra ─ meatier, faster maturing and better layers than their tamer counterparts which brings a timely solution to our ever demanding and ever growing meat and egg markets here.