I’m sure you will be fine! The main thing is you are getting prepared and seeing these issues coming - a little preparation goes a long way! If in doubt just stick to the lower calcium feeds and offer oyster shell / calcium / protein supplements additionally to a basic feed that you think is safe for all. Personally speaking I wouldn’t be too fearful over too much protein it’s something I find I have to supplement fairly often, particularly in times of stress, but I do think you are right to be cautious over too much calcium too young.
Different breeds also mature at different rates too.... brahmas for example take a long time to mature.... so don’t get too hung up on having to feed this food “x” at 12 weeks or “y” at 16 weeks. Do judge what is best for your chosen breed/s. Traditional breeds and large fowl can take longer to reach p.o.l. Commercial feeds are principally made for commercial hybrid layers which mature quickly. If you fancy it take a look at fermenting feed and using whole grains & seeds in your hens diet - it’s not as daunting as it might sound and you might find it easier (& more economical?) managing everyone’s nutritional needs safe in the knowledge there isnt excessive calcium or protein mixed up in the feed. You may well see a difference in the quality of their eggs? Equally some people find commercial feed better / easier? There’s no right or wrong it’s just working out what works best for you, your set up & your hens!
Try not to worry - it sounds as though you are doing well so far! Enjoy your chickens & best of luck!
Different breeds also mature at different rates too.... brahmas for example take a long time to mature.... so don’t get too hung up on having to feed this food “x” at 12 weeks or “y” at 16 weeks. Do judge what is best for your chosen breed/s. Traditional breeds and large fowl can take longer to reach p.o.l. Commercial feeds are principally made for commercial hybrid layers which mature quickly. If you fancy it take a look at fermenting feed and using whole grains & seeds in your hens diet - it’s not as daunting as it might sound and you might find it easier (& more economical?) managing everyone’s nutritional needs safe in the knowledge there isnt excessive calcium or protein mixed up in the feed. You may well see a difference in the quality of their eggs? Equally some people find commercial feed better / easier? There’s no right or wrong it’s just working out what works best for you, your set up & your hens!
Try not to worry - it sounds as though you are doing well so far! Enjoy your chickens & best of luck!