So is the consensus to keep feeding them the starter/grower until they lay...? I'm still confused. HELP! lol
Sorry to confuse you.
Try not to complicate it.
Other than protein and calcium, most chicken feeds have the same levels of other nutrients. A hundred years of research in optimal nutrition has shown how much of each vitamin, mineral, amino acid, fat, etc. is needed by a chicken.
So the 2 things to keep in mind are protein and calcium. Actively laying birds need more calcium. Growing bodies need protein, mature birds not so much.
A chicken that is not laying eggs (i.e. building shells) needs very little calcium. That would be chicks, growing birds, roosters, molting hens and setting hens.
Excess calcium is processed by the kidneys and can overload resulting in kidney stones, visceral gout and other problems.
Throughout a chickens life, just like with humans and all other animals, protein needs change.
Young chicks need more protein to build their growing bodies. For that reason, starter feed is higher in protein. Usually anywhere from 18-24%. As they mature, and their organs and tissues aren't growing as much, the protein needs are less. Grower feeds are usually from 16-18% protein. Grown birds not yet laying and roosters can get a finisher, about 15%. When birds molt, they're building a new winter coat. Feathers are about 90% protein so molting season is when a grown bird can use higher protein.
Excess protein isn't as bad as excess calcium but still has to be processed by the liver and kidneys and if it goes on too long could cause problems like articular gout.
Each retail feed manufacturer has a line of feeds for various life stages. They're trying to put out an acceptable product at a competitive cost. Protein is expensive and all protein isn't created equal. Chickens have even more amino acids they can't assimilate and are essential than humans. So the feed ingredients have to complement one another.
Most feeds have grains and legumes as the primary ingredients. The amino acids missing in grains are found in legumes and vice versa. Animal protein is superior as it isn't missing any amino acids but it's hard to find a commercial feed that has animal protein.
Commercial operations (egg and broiler producers) make their own feed but what you can buy at the store is based on the same research. They start a flock of thousands of birds at the same time and it's easier to tailor their feeds to meet the birds needs since they're all the same age. They don't mix ages. They have their replacement pullets on a lighting regimen that keeps them on about 8 hours of light until about 16 weeks of age when they start increasing light until they get to 14-16 hours of light. This way they stimulate the birds to all commence laying at the same time. Usually when they get 5% egg production they switch to a high calcium layer feed. If they lose some to urolithiasis, they don't care because that flock has 20,000 birds in it.
The Starter/Grower is two feeds in one. Its meant to replace to two different feeds 'Starter' and 'Grower' with the one blended food. You wont have to change feeds until they start laying. Then your next bag should be layer. If you still have a lot of Starter/Grower you can just supplement with oyster or crushed egg shells to bring the calcium levels up.
I have been saving up my egg shells for months just so i would have a readily available calcium supplement on hand if its needed.
I'm not sure but i have all ways thought finisher was for birds raised for meat. I have always raised layers so have never needed finisher.
Basically, you're right. As an example, Purina Start-n-grow is 18% protein and has a crumble size that is appropriate for chicks and growing birds.
Finisher is usually for meat birds the last couple weeks but can be used for pullets prior to onset of lay when their protein needs lessen. Roosters are better off with about 15% protein as well.