If you don't mind, which hatchery said that? I don't know if they had anything specific in mind or if it is just a general comment. I like to read these things in context if I can.Why would my hatchery tell me not to til 7 weeks... they said bc their immune system is still weak
Their immune system will stay weak until they work on strengthening it. If they are talking about Coccidiosis they strengthen their immune system by being exposed to low level dosage. After two or three weeks of exposure they develop an immunity to that strain. The danger for Coccidiosis is when they are exposed to large amounts of that bug, then it can overwhelm their system. If they have not developed that specific immunity their age doesn't matter. More than 7 weeks does not matter. For Coccidiosis that overload can come if they are in a wet environment for several days. For Coccidiosis specifically I want them to get that exposure while they are in the brooder where I can more easily control how wet it gets and how long it stays wet.
I have older chickens so I take dirt from their run and start feeding them small amounts of that dirt from about the second or third day in the brooder and repeat every three of four days. That gets grit into their system, gets them started on certain immunities if that is in the environment, and gets them probiotics from the adults. The way I read your posts you don't have older chickens so your benefits would not include any probiotic benefits and maybe not immunity benefits.
I like starting them on grit very young, you can buy chick grit if you don't want to feed them dirt. Grit gets their system set up the way it needs to be in case they do eat anything that needs to be ground up in their gizzard. Things like certain bugs, bits of greens, or wood shavings. Don't feed enough to impact their crop, some silly chicks will eat a lot.
One of the first things my broody hens do is take their chicks to a patch of bare ground where they can peck. They get grit, probiotics, and start on immunities from that and are ready to eat anything. It doesn't bother me if chicks eat a little of something other than their chick feed. When my broody hens are raising them I really don't worry about that. But their chick feed is a balanced diet. It contains everything they need nutritionally. You do not want to feed enough of anything else to unbalance their diet.
It is a lot like it will not hurt your kids to have an occasional ice cream or piece of candy as long as that is a minor part of their diet. You want most of what they eat to be good for them. An occasional treat will not stunt their growth or ruin their health as long as you do not overdo it. If you feel you have to give them mealworms or another treat go for it but keep the quantities small. And realize that is for your benefit and how you feel, not for theirs. The chicks will enjoy them for sure but they will not hate you if you don't give them mealworms.
