It probably has more to do with the change in daylight and with the absence of the roosters, although the stress of losing them might have an effect as well. Hens need a lot of light in order to produce an egg. Unless you are providing artificial light in the chicken coop, your hens may stop laying until the spring. If you really need the eggs, I suggest putting an artificial light in their cop and making sure they have approximately 16 hours of light a day. There are pros and con's to artificial light, but either way, the lack of light is probably the culprit.
If you could describe your setup, other people might be able to weigh in and give you more specific suggestions.