The Life of a Chicken

It is funny….I often sit and try to think of a subject for a post for the blog.  Nothing too sciencey”, or too basic….nothing boring (hell…thats what we have schools for!).  Sometimes I forget that I grew up with chickens, and the most basic things are mysterious and interesting to a lot of you.

So, with that in mind, I am going to give you a highlight by highlight description of a typical chicken’s life…in a commercial setting, or in a backyard.

Day 1….an egg is born

Chickens naturally live in a harem of 8-12 hens per rooster.  As such, he is not able to breed each hen each day (I’m sure he starts off trying, but at some point, the riches of female companionship overwhelm him).  As such, hens are able to store semen for about 3-5 days, and will lay fertilized eggs for that long after being bred by a rooster.  Like many mammals (not to name names….) the males are loud, large and aggressive, but the female controls the mating schedule, and if a rooster gets out of line, his ladies will VERY quickly set him straight (it’s called “hen-pecked” for a reason, and is a common cause of rooster injury and mortality on breeding farms).

Day 21 – Bustin’ Loose

This picture is posed....newly hatched chicks are wet and, lets face it, ugly. This was too cute to omit though.

The chick…who has been singing for several days now, finally leaves the “small time” and emerges from her egg.  After drying off, she is cuter than she will ever be again in her life.  She will live for 3-4 days on the yolk material she internalized from the egg.  She has that long to discover water and food in her environment.

Day 1 (the old day 21, but now start counting days of “chickenhood”) to 14 weeks

The cute little chick grows into a pullet.  She grows relatively slowly, developing organs, bones and muscles in different phases.  There is a period of primary organ growth, followed by frame growth (bones), followed by muscle growth, followed by sex organ growth (as puberty approaches).  In commercial flocks, several feed phases target these times, while in backyard or extensive flocks, usually chick starter and pullet grower are all that are used.  The following scheme works well for backyarders….

An effective pullet feeding strategy for backyard flocks.

14 weeks to 19 weeks – Puberty and a New World

Now is the time that the pullet starts to become the “amazing egg producing genius”.  Her ovaries, uterus, shell gland and comb develop as hormones cascade through her body.  It is now that she will lay her first egg, but it is before the first egg that her nutrition is crucial.  Under the hormonal control, hen’s bones change, and her ability to store calcium for eggshell production for the rest of her life is established.  If you don’t give her enough calcium early enough, she will be impacted for the rest of her life.  High levels of calcium should be given a week or 2 before her first egg is laid.  (I know…its like saying, you should take a left at the intersection a mile before the bridge)  This is fairly easily judged in professional farms, since the breeds are very consistent, the birds’ development is constantly monitored, and the farmers have lots of experience (usually).  In backyard flocks, it is a good idea to provide oyster shell for the flock to pick at if they want to at about 15 or 16 weeks of age…if they want it, they will eat it…if not, they won’t.

Now is also the time that egg production is messed up.  The cycle is erratic, double yolked eggs are more common than any other time….eggs laid with no yolks aren’t rare, and I’ve seen everything from triple-yolked eggs to an actual fully formed egg INSIDE a second egg white and a second shell.  Once the hens get on track, their hormones settle down and their nutritional needs stabilize, these freaky egg events mostly disappear.

Week 19- ~80 weeks

Boring old laying hen period.  All she does is the equivalent of a human having a 7 pound baby every day.  She is one of the most efficient converters of vegetables (yuck) into animal protein (Mmmmm), with a feed conversion of 1.9 or less.  This means that for every 2 pounds of feed, you get about 8 eggs.  Also, the protein in eggs is still the standard by which all other proteins are compared.  Egg protein is evaluated as a 1.0 for quality (makeup of amino acids, and digestibility).  Beef protein scores a 0.93, while wheat gluten is 0.25.  This means that the value of protein you can get from an amount of wheat gluten is only a quarter of what you can get from an egg.

Hens are also amazing in that they can (and do) eat almost anything.  Corn, soybeans, wheat, worms, grubs, tomatoes, mice, and anything dead will be happily turned into eggs by these voracious omnivores.

After Week 80 (or 72 in Canada) – End of first Lay Cycle

After laying eggs for a year, hens are getting tired.  In the past, it was common to molt hens to get them to stop laying eggs (surprisingly hard to do…they are the original workaholics).  This is true in professional barns, and in backyards.  Hens start looking like this:

A tired backyard hen, naturally starting a partial molt

Professional farmers in many jurisdictions in the world will “molt” hens by giving them a very low nutrient diet.  This causes the hens to stop laying, at which time, they will drop most of their feathers (like the hen above, only more so), and then re-set their hormones, regrow their feathers, re-build their bones and rejuvenate their entire bodies.  After about a month, they will start laying eggs again, and look like young pullets again.  There is a lot of discussion on the welfare implications of molting, and different methods of encouraging the birds to stop laying are being experimented with.
In Canada, the egg farmers never molt flocks unless there are some extremely extenuating circumstances (like barn fires, or some other catastrophe….I know of only 2 flocks molted in the past 10 years).  After a year of lay, hens in Canada are sent to a processing plant to be made into processed chicken products or soup.
If you want to keep your backyard flock longer than a year and a half or so, it is important to give them a rest (See my previous post “Chickens need rest too”), get them to stop laying eggs for a while, and let them rejuvenate themselves.  It is a normal, natural and necessary process.  Most birds will molt while brooding their eggs…..sitting still on a nest decreases the amount of food available drastically, and all those dropped feathers go to great use in lining the nest!!!
Now, your hen is ready to start magically delivering eggs again….turning bugs and veggies into omelets and quiches.
Mike the Chicken Vet

2 responses to “The Life of a Chicken

  1. I had no idea about molting. I help with a friend’s flock this is free ranged all day, until they go into the coop at dark. Mostly Americaunas, the other 2 varieties escape me (an Egyptian…famoya I think) and a couple of big black ones, maybe Cornish. It is a flock of around 25 with 5 guineas also running around. A big daddy rooster, and lately 3 other roosters, the oldest being 4 months at most (have yet to see him mount anyone) and a teenager and one that is maybe 3 weeks old, and one or two now just born several days ago. I wonder why I’ve never seen any of them molt? Sometimes, like now, egg production goes way down…I thought because of the heat. And what about the lifecycle of roosters? My friend has gotten to eating the extra roosters, because more than one is just too hard on the ladies. However, I’ve become attached to the young adult rooster and will hate to see him go.

    • Sometimes, chickens will partially molt. They go through the same hormone changes, and go out of production, but the change in hormone levels is slower, and the feather loss is less dramatic. Hens bred for high egg production usually have more dramatic feather loss……presumably because their hormone levels are higher and drop off faster.

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