I am getting a chick from one farm, and an older pullet from another farm. They will be my only 2 chickens. I'm concerned about bio-security, but there's no way I'm going to be able to separate them from each other once they are here. Since I don't have an existing flock and have never had birds here, and I know my 2 sources are clean and disease-free, can I just put them together from the start? I don't plan on getting any more birds until Spring, so these two will be 'quarantined' together all winter.