i use aspen in my brooder and with any of my animals that live in cages. i have kept many reptiles and rodents in the past so i was always warned against ceder and pine and always have bags of aspn bedding. the horses get pine shavings but they are outside in the open so it can easily air out. i have never personally had any problems with pine bedding but the only time i use it is with really good ventilation. my guess would be yes, aspen is a better choice of bedding for young and fragile chicks if you can easily get ahold of it(not everywhere carries it though and its usually more expensive than pine).