When to switch Growing Chicks to Layer Feed

We received a few questions at the hatchery that I thought I’d answer through the blog:


1)    When do we switch from chick starter to layer feed?


The short answer to this is: when your pullets lay the first egg.  There are really two things to consider when switching between feeds.  The first is protein.  The growing chick’s body needs more protein than a layer feed provides.  In the first 6 to 8 weeks of life, chicks grow extremely fast and the demand for protein to build muscle, bone and tissues is critical.  Too little protein early on and your bird will be set up for sub optimal health and productivity throughout its life.  Standard chick starter feeds provide anywhere from 18 to 20% protein.  We prefer to feed growing chicks a higher protein than this, by feeding ours a 23% chick starter.  By week 8, the growth curve of the chick has leveled some from it’s early exponential growth and a lower average protein is ok. A higher protein level is fine, but is not necessary.


One thing to consider in designing a feed for any poultry, protein is where the bulk of the cost comes from.  The higher the protein, the higher the cost.  Most commercial feeds are based on commercial flock demands.  Production birds are being grown by the 10’s of thousands, and 1% of protein added to over 250,000 birds adds up to big money.  Commercial operations are looking for the perfect formula to grow birds to the optimal health for the least cost.  (Optimal here may not mean healthiest.)  A commercial flock, however, has every environmental detail controlled. Birds are in enclosed houses where temperature, humidity, feed consumption, water, air quality, are all closely monitored and controlled. A backyard flock, while more natural, does not have the luxury (if that’s what you call living in those conditions) of a controlled environment. For that reason, my preference is to error on the side of over-providing the chicks nutritional needs.  Higher levels of protein for longer, higher quality vitamins and minerals, etc.


The second consideration for switching a bird to layer feed is the calcium content.  Layer rations have extra calcium added to keep up with the hen’s bodily demands for producing an egg shell every day.  Without supplemental calcium in the diet the hen’s body robs calcium from other areas, particularly the bones, to make the shells.  Over time, the shells become more and more thin and deficient.  Extra calcium in the feed helps prevent this from happening.  A chick’s body is quite different.  Without the pull of calcium from the body into the shell of eggs, the calcium levels in typical layer rations are too high for chicks to handle.  Too much calcium will have detrimental effects on both bone and muscle, and, in fact, can become toxic.


A good rule of thumb when transitioning birds from growing to laying is to make the switch when you get the first egg.  However, I also recommend that at about 18 weeks of age, you put out “free choice” crushed oyster shell.  We simply attach a butter tub to the side of the coop and keep it full of crushed oyster shell.  As the chicks body prepares for the transition to egg laying, it will cause her to seek out extra calcium as she needs it.


2)    As the chicken is switched from starter feed to layer feed, do we need to add grit to the diet?


It depends on what types of food your chickens have access to.  If thier diet is going to be primarily a layer pellet or crumble, and whole grains and other organic material is limited, then no.  Commercial feeds are basically already processed enough to be readily absorbed into the chicken gut.  However, if you are feeding your flock a varied diet, particularly if it contains a reasonable amount of whole grains, then they will need a source of grit.  As a chicken eats, food is stored in a large sack located at the base of the neck called the crop.  This food is then slowly moved into a small muscular pouch called the gizzard.  It is here that food is ground up into a mush that can be absorbed into the blood stream.  If there is a lot of whole grains, or natural graze food, it is helpful if the gizzard has small stones (or grit) in it to help mechanically grind the food.  If your birds have access to free range, you don’t need to provide any grit. They will find everything they need.  If, however, they are confined to a coop and run, and you are providing foods that need mechanical assistance to be ground up, then yes, it is a good idea to provide grit.  This would be like crushed oyster shell (which is often used by the bird as grit) in that you would want to provide it as free choice.

12 Responses to “When to switch Growing Chicks to Layer Feed”

  • ibe kelly:

    Thanks Prof for your info.

  • Gina Brown:

    I’ve got chickens that are 7months and some that are 3 months. They have all well socialized together. This is the problem, I can’t keep the big girls out of the little girls feed! I have had oyster shell out in a dish for months. This morning I found an egg without a shell. I know this can happen, but am worried it’s because of the feed. Any suggestions?

  • Hey Gina, Great question. Rest assured, with the age of your girls and the fact that you ave free choice oyster shell available, the shell-less egg was almost certainly not because of the feed. This just happens sometimes. Most often it’s because of a stressful event that a bird had that will cause them to disrupt the normal egg laying process. If it becomes a chronic problem, it’s most likely a hen that has a genetic predisposition to laying shell-less eggs.

    The challenge of feeding new birds with an existing flock is exactly what you described. You should offer both types. The reason your big girls are going after it is because of the higher protein level. They crave it. There is no problem with them eating it. The reason most commercial feeds are 16% versus the 20% of most chick feeds, is that protein is the most expensive ingredient. Your big girls getting extra protein is fine, as long as they have the option of getting more calcium when they need it.

  • Grant:

    Just a little input/correction, oyster shells are NOT a source of grit. Oyster shells are softer than grit. Grit is considered to be substituted by granite or cherry stone. Oysters shells are to help produce a hard shell when laying.

    • You are correct in that it should not be used for the purpose of grit. But it will act as a hard surface to assist the mechanical emulsification of the food. I don’t recommend that grit be used in any situation however. Chickens will pick up appropriate stones and gravel from the environment.

  • Vera:

    I thought after eight weeks, pullets are fed with growers mash till first drop before changing to layers mash.

    • That is one strategy. it is the one used by industry because the most expensive component of feed is the protein. With a closed feeding system (no opportunity for free range diet, you can take a scientific approach and design an effective food program using the most cost effective formulas. For a backyard flock, I prefer to bias toward a more protein rich diet. With just a few birds, the extra few cents are not meaningful. With a house of a million birds, 1% difference in protein is a big deal.

  • Walt Sterling:

    My girls have relished the growth crumble, and when I introduced the layer pellet, they pushed it asside, and refused to eat same. How can I convert to the new food type?

    • They are not used to seeing a pellet. Therefor, they’re not sure what it is, even though it is basically the same food in a different form. Start by mixing some mash with pellet and gradually change the mix ratio until it is all pellet.

  • Kathy:

    Hi! I have an 8 week old chick (pullet) who is not walking well at all. She stands, and can take a few steps but then falls over, usually she falls forward like she’s top heavy. I’ve examined her legs and there doesn’t seem to be any injuries or growth malformations. She eats, drinks and looks very bright. No respiratory issues at all. I take her outside when I free range the other 12. I’m just letting them out in the evening for an hour or so. She stays in a cage in the basement with my cats.
    Thanks for any ideas,


    • Hi Kathy,
      Obviously, without testing for various things by a vet, I’m stabbing in the dark. Without any other symptoms showing, it seems like she has a neurological defect. At that young age, Marek’s in extremely unlikely. And with no respiratory symptoms, it’s unlikely that something is messing with her inner ear. It’s possible that she picked up a toxin through free ranging. But again, extremely unlikely. (Unless she ate a toxic mushroom.) Sorry, not much help. Without vet care, the best thing to do is give her supporting care and rest, just like you are doing.

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