Operation of a chicken farm will involve biological assets and shall be treated as per IAS 41 - Agriculture. As per IAs 41 definitions, biological assets mean living animals and plants [IAS 41.5] and agricultural produce means the harvested product from biological assets [IAS 41.5]. Therefore the eggs are agricultural produce and should be treated accordingly.
Agricultural produce should be measured at fair value less estimated costs to sell at the point of harvest [IAS 41.13]. Since eggs generally have a an active market your fair value would be the current market price and costs to sell, if any.
Note that IAS 2 - Inventories specifically excludes biological assets and produce from its scope.
