Mae'n bwysig deall diben y ddau fesur hyn – caiff Ffliw Adar ei ledaenu yn niferion rhai rhywogaethau o adar gwyllt, adar y dŵr yn bennaf. Felly, mae'n hanfodol atal adar sy'n cael eu cadw rhag dod i gysylltiad uniongyrchol ag adar gwyllt a allai roi’r ffliw iddynt.  Mae lletya yn cyflawni’r diben hwn.
It is important to understand the purpose of these two measures – Avian Influenza is spread in the droppings of some species of wild birds, mainly waterfowl. It is therefore essential to prevent kept birds from coming into direct contact with wild, carrier birds. Housing does this.