The study was conducted using 4x4 Latin square design in 4 Awassi lambs at the age of 6 months and at the same weight. The research groups were determined according to the conservation method. Y group ensiled as fresh on the same day of harvesting, Pt group ensiled after wilting 24- 48 h on the ground, Y+S group, ensiled as fresh by adding straw treated with HCl (fresh material 80% + straw 20%) and Kt group were dried on the ground. The highest digestibility of dry matter, ash, organic matter, crude fiber, crude protein, eter extract and nitrogen free extract was found in Y+S group and this was followed by Pt and Y groups, respectively (P<0.05). The lowest digestibility of the nutrients was detected in Kt group (P<0.05). In this study, it was aimed to put out the effects of 4 different conservation methods of whole-crop oat on digestibility of nutrients in sheep.