ARTICLE FEED & ADDITIVE MAGAZINE January 2023 51 A recent study done by SEGES (leading innovation center in Denmark) and published by Nielsen et al, in 2022, revealed the apparent total tract digestibility (ATTD) of 6 different zinc sources supplemented during the first 14 days after weaning at 100ppm Zn (figure 1). Potentiated zinc (HiZox®) displayed a numerically improved bioavailability among sources compared to other inorganic sources and even an organic source such as Zinc Glycinate. This may be due to its unique physico-chemical properties that makes its dissolution optimal, steady rate to provide a continuous diffusion of ionic zinc without binding to antagonists. TIPS 2: CHOOSE CAREFULLY YOUR NEW ZINC SOURCE Recent publications highlighted why considering physical & chemical characteristics of zinc sources is crucial to predict their bioavailability. During a 3-year PhD thesis, more than 30 well-defined grades of zinc oxide (ZnO) were collected from around the world and analyzed. The results showed that their micro characteristics strongly influence their dissolution kinetics and thus final bioavailability. The different analyzed sources can be sorted into three main categories: • ‘Large Dense Particles’ (LDP) are found in coarse ZnO powders. These are large non-porous particles which dissolve too slowly to become bio-accessible to the intestinal zinc transporters and thus have poor bioavailability. • ‘Small Aggregate Particles’ (SAP) are powders with a smaller particle size, high Specific Surface Area (SSA) and lower density than LDP. These powders dissolve too quickly, rapidly bind to antagonists and have limited final bioavailability. • ‘Small Aggregated and Agglomerated Particles’ (SAAP). Potentiated zinc (Hizox®) is alone in this category, it is a source with a larger particle size than SAP but with a high Specific Surface Area. It dissolves at an optimal, steady rate to provide a continuous diffusion of ionic zinc. TIPS 3: FOCUS ON ZINC SOURCE ABLE TO IMPROVE GUT INTEGRITY A review of 20 published papers explains the impact of zinc oxide on gut integrity. This parameter is key around weaning to avoid mucosa depletion and secure tight junctions in a period when feed intake is compromised. In this review, supplemented doses of zinc oxide were sorted in 2 categories: medium zinc levels (from 200 to 2000 mg Zn) or high zinc levels (from 2000 to 3000 mg Zn). The summary revealed as High Concentration Flowability Safety standards Stability Bioavailability Animal performance POTENTIATED ZINC POTENTIATED ZINC MONOVALENT COPPER HIGHLY PURIFIED MANGANESE an international and independent supplier of precision minerals , www.animine.eu
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