Raising Baby Chicks

[Ttheresaa]

Hi everyone i am new to the site and i have a problem. I hope someone can help me. I have 18 production red chickens my husband bought me some chickens from a guy. We got the chickens home 2 days later one of the chickens got sick then the rest of the chickens and my production red chickens got sick. I talked to a vet and he told me to use LS 50 which is a powder that you mix with their water. I got all the chickens well. anyway I have been incubating the production reds eggs and getting babies. The first hatch and second hatch i had the brooder in my house. I had 31 babies i sold them the second hatch i had 39. i sold them. now my third hatch i moved the brooder in the coop with the production reds. I had 29 babies out of 42 eggs. since the brooder has been in the coop the production red chickens is eating the babies feed and the babies are dying. I don't know if it is because i got the eggs when it was to cold or if it is because the production reds are eating their food and still be carring their sickness in their immune systems and the babies are dying or a bad hatch. Please if you could help i would apperciate it.