Supplementary Effect of Different Levels of Nano Zinc Oxide on Zinc Bioavailability and Blood Metabolites in Lambs

Twenty five Jalauni male lambs (average body weight = 4.5 kg, age 35 d) were randomly divided into 5 groups of 5 animals each. All the lambs were maintained on basal ration comprising grass hay and concentrate mixture (Maize grain, mustard cake and common salt in the ratio of 64: 35: 1). The group G₁ served as control supplemented with 40 ppm zinc from ZnO while the lambs in groups G₂, G₃, G₄ and G₅ were supplemented with 40, 30, 20, 10 ppm Zn from nano ZnO (nZnO 30 nm) in the concentrate mixture over and above the basal ration (24.12 ppm) for a period of 150 d. Results indicated no difference in the intake and digestibility of nutrients amongst groups. The Zn intake was higher (P<0.05) in group G₁ and G₂ as compared to groups G₃ to G₅. A similar trend was also observed for faecal and urinary Zn excretion which was higher (P<0.05) in group G₁ as compared to groups G₂, G₃, G₄ and G₅ that led to higher Zn retention (2.01 and 1.88 mg/d) in groups G₂ and G₃ as compared to groups G₁, G₄ and G₅ (1.50, 1.40 and 1.33 mg/d) and absorption was higher (P<0.05) in nZnO supplemented lambs in comparison to ZnO supplemented lambs (G₁). The blood metabolites were within the normal physiological range except that plasma Zn concentration was higher (P<0.05) in nZnO supplemented lambs. Hence, nZnO improved (P<0.05) Zn availability in lambs. Thus, nZnO could be a better source of Zn supplementation at a supplementary level of 20 ppm.