Comparison of dietary supplementation of sodium selenite and bio-nanostructured selenium on nutrient digestibility, blood metabolites, antioxidant status, milk production, and lamb performance of Barki ewes

Selenium (Se) supplementation during early lactation can affect not only the ewe's health and milk production but also their lamb performance. This study aimed to investigate the effects of dietary supplementation of two different forms of selenium [inorganic form as sodium selenite (SS), and bio-nanostructured selenium (SeNSM)] on ewes nutrient digestibility, milk yield, milk composition, blood biochemical parameters, and their lambs' growth performance. Twenty-one Barki ewes [32.72 +/- 0.84 kg initial body weight (BW), 14 +/- 7 days in milk] were assigned according to BW and milk yield from the previous lactation period into three experimental groups (n = 7 ewes/ group) for a period of 50 days. The control group fed the basal diet without Se addition, the SS group fed the basal diet supplemented with SS at 1.2 mg/ kg dry matter (DM), and the SeNSM group fed the basal diet supplemented with SeNSM at 1.2 mg/ kg DM. Supplementation of SeNSM improved (P = 0.053) neutral detergent fiber digestibility compared to the control. No differences were found among the treatments on blood metabolites, however, both Se forms tended to increase (P < 0.01) the blood Se concentration compared to the control. Ewes fed SeNSM had higher (P < 0.05) blood Glutathione peroxidase (GSH-Px) activity, milk yield, fatcorrected milk, milk fat, protein, lactose, and ash yields, and milk Se than ewes fed the control diet. The lambs of ewes fed SeNSM had higher (P = 0.03) BW gains compared to other treatments. In conclusion, the Se of SeNSM form was more effective than SS in improving the productive performance of both ewes and their lambs.