From the present book, it can be concluded that bioaccessibility of minerals estimated by in vitro technique was found to be higher in mustard cake as compared to GNC. Bioavailability determined by in vivo technique, showed higher value for apparent absorption in mustard fed group than GNC fed group, so from present book it can be concluded that the mustard cake is a better source of bioavailable minerals. Value obtained with in vitro experiments were higher as compared to in vivo study, though the trend was similar thus it can be inferred from that finding in vitro method can be used for prediction of mineral release from feeds and forages, however validation by actual feeding is required before accepting the bioavailability or absorption coefficient values while considering these for dietary requirements.