pullets with orange diarrhea

[kaisercl]

my pullets freerange all day long they are about 15 to 17 wks old with 2 2yr old roos and 2 14mos old hens i bought some yogurt for them but how much should i give them i have 16 total should i put it in one bowl or split it up because they dont all eat together and some seem to eat more than others plus i just gave mine wazine and i dont know if the people i got them from ever gave them anything when should i do it again and how do u give the ivermectin and where do u get it from