Effect of feeding nano-ZnO on performance, rumen fermentation, leukocytes, antioxidant capacity, blood serum enzymes and minerals of ewes

Abstract

Abstract This study was conducted to assess the influence of dietary supplementation of nano Zn oxide (nZnO), compared to Zn oxide (ZnO), on performance, rumen fermentation, leukocytes, total antioxidant capacity (TAC), blood serum enzymes and minerals in the ewes. Thirty pregnant Khorasan-Kurdish ewes were assigned to one of the 3 experimental groups (10 replicates) in a randomised complete block design. The ewes received 1- control diet without supplementary Zn, containing 22.4 or 24.3 mg of Zn/kg dry matter (DM) for pre- and post-partum periods, respectively, 2- diet supplemented with ZnO (30 or 40 mg of supplementary Zn/kg DM for pre- and post-partum periods, respectively) or 3- diet supplemented with nZnO (30 or 40 mg of supplementary Zn/kg DM for pre- and post-partum periods, respectively). Dry matter intake (DMI), DM digestibility (DMD), rumen parameters, milk performance and blood leukocytes of the ewes were determined. Moreover, the ewes and their suckling lambs were assessed for TAC, blood serum enzymes and minerals. Regardless of Zn form, the additional Zn increased DMD, DMI, ruminal volatile fatty acids (VFA), milk yield, TAC and blood serum Zn, but decreased milk somatic cell count (SCC) and ruminal ammonia-N (P 0.05) the TAC, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, Cu, Ca, P and Mg concentrations in the blood serum of ewes. Moreover, feeding the mother ewes with the diets containing supplementary Zn sources had no effect (P > 0.05) on the blood serum concentrations of TAC, enzymes and minerals in their suckling lambs. Overall, the use of nZnO instead of ZnO could be a useful way in improving DMI, DMD, TAC in the rumen fluid and milk, leukocytes and milk Zn concentration of the ewes, without adverse effects on the blood serum concentrations of Cu, Ca, P, Mg and Zn-dependent enzymes.