just about a month ago i was getting on average 12 egs a day. then i treated my flock for worms using wazine and then followed up 2 weeks later w/ivomec pour and i also dusted all my entire flock and the coop w/sevin and repeated that 10 days later. during the egg withdrawal time my egg count went up to 14-16 eggs per day. i was exited that the egg count went up because to me that showed me that the meds were working and the hens were feeling better. well the withdrawal time ended on the 20th and their their 14-16 egs per day streak also ended that day, i'm now down to 7-8 eggs per day and it's been this way for 4 days now. now in the past week there has been a couple of snow storms and single digit temps and i also switched feed on them(not by choice). i ran out of their normal feed which i was giving them a mixed blend of layer mash and gamebird crumbles and the only place that i was able to get to on short notice carries a different brand of layer crumbles. they have been on this feed for about a week now. so could the extreme weather conditions or/and the change of feed be the culprits for the low egg count? since then i've checked my birds for any lice which is why i dusted them & also looked for mites which i have never noticed and yet to see. i'm sure that the wazine & ivomec did away with any internal parasites..... so does anyone have any guesses as to why my hens are producing less?