Abstract
This study investigated the relative bioavailability (RBV) of zinc from different sources used as feed additives in ruminant nutrition based on Zn concentration and the activity of Zn-dependent enzymes in lamb tissues. Thirty-two male lambs of Improved Valachian breed (three months old) were randomly assigned to four dietary treatments. For 120 days, the lambs were fed either the total mix ration (TMR) providing 29.6 mg Zn/kg or the TMR supplemented with either zinc sulphate (ZnSO4), zinc chelate of glycine hydrate (ZnGly), or zinc chelate of protein hydrolysate (ZnProt). The supplemented diets contained a total of 80 mg Zn/kg. Supplementation with ZnSO4 increased Zn concentration in the liver, while the highest Zn uptake was in the kidneys of lambs fed the ZnProt diet. The ZnGly supplemented diet elevated the activity of the Cu/Zn-dependent enzyme superoxide dismutase (Cu/Zn SOD) in the liver. Regardless of Zn source, Zn supplementation resulted in increased total antioxidant status (TAS) in the pancreas. The estimated RBV of Zn based on linear regression slope ratios did not differ among the Zn sources. Our results indicate similar availability of Zn from organic dietary sources as from commonly used zinc sulphate; however, their effects on mineral and antioxidant status may differ slightly in growing lambs.
Highlights
Definitions for mineral bioavailability vary because of the complexity of the issue
Zn requirements for growing lambs and calves are recommended at 33 mg Zn/kg of dry matter (DM) in a complete diet, young ruminants require additional Zn to support accretion of body protein during periods of rapid growth, and improvement in growth performance, health and reproduction, mineral and antioxidant status, and immunity in ruminants has been reported after Zn supplementation [3,6,7,8,9]
The 120 day period of feed supplementation with organic Zn proteinate (ZnProt) increased the plasma Zn concentration compared to the control treatment (p = 0.028, Table 3), while the MT concentration in plasma was reduced during the zinc chelate of protein hydrolysate (ZnProt) treatment (p < 0.05)
Summary
Definitions for mineral bioavailability vary because of the complexity of the issue. From a nutritional point of view, the bioavailability of minerals can be defined as the proportion of ingested trace elements utilized for their specific physiological and biochemical functions at the site of action [1]. Zn requirements for growing lambs and calves are recommended at 33 mg Zn/kg of dry matter (DM) in a complete diet, young ruminants require additional Zn to support accretion of body protein during periods of rapid growth, and improvement in growth performance, health and reproduction, mineral and antioxidant status, and immunity in ruminants has been reported after Zn supplementation [3,6,7,8,9]. Zn supplementation with Zn nanoparticles can offer an effective approach to maintaining the high production and health of ruminants due to the improvement in animal reproductive efficiency, immunomodulatory properties, and enhancing the microbial biomass production, while it can help to reduce methane emission in livestock [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
