Determination of the nutritional potential and valorization of saffron (Crocus sativus L.) wastes as an antioxidant agent in ruminant feeding: in vitro and in vivo studies.

Saffron (Crocus sativus L.) is a plant known for its diverse medicinal and nutritional properties, which has adapted well to arid and semi-arid regions of the world, particularly in the Middle East. Research on saffron wastes (SW) as a dietary additive for small ruminants is limited. Therefore, two primary experiments were designed to evaluate the nutritional potential of SW. In the first trial, the nutritional value of SW collected from various regions in northeast Iran was assessed through proximate analysis and in vitro procedures. In the second trial, the effects of incorporating SW (a 1: 1 mixture from all regions, w: w) at two levels (30 and 60 g/day) into the diets of Afshari male lambs were investigated in comparison to a control diet. Except for dry matter and ether extract contents, other chemical and mineral compounds varied among the SW collected from different regions. The samples displayed diversity in potential gas production and estimated dry matter intake (DMI). In the in vivo experiment, DMI, nutrient digestibility, and most blood metabolites were not significantly affected by the addition of SW; however, malondialdehyde, total antioxidant capacity, and cholesterol levels were respectively decreased, increased, and decreased in lambs fed 60 g SW/day compared to the control group. Overall, SW collected from various regions demonstrated different nutritional values. Although the dietary inclusion of SW at the level of 60 g/day did not adversely effect on DMI, nutrient digestibility, or certain blood metabolites, it is suggested for its potential improvement in lambs' health indicators. Long-term studies are recommended for future SW evaluation in vivo.