ISSUE FOCUS FEED & ADDITIVE MAGAZINE February 2023 33 ume of a complete mix, trace minerals represent a very small portion of the feed. Using the example above, the actual amount of trace mineral added per ton of complete feed would vary from a low of .11 kgs to a high of .67 kgs (.011-.067% of the total mix) based on the trace mineral form selected. Care must be taken to ensure that required trace minerals are being properly selected and accurately weighed within the premix/complete feed. 3. Mixing and sampling: Ensuring uniform mixing of trace minerals within a premix or complete feed is essential. A broiler for example that is fed up to 42 days of age with a diet containing 80 mg/ kg of Zn will consume less than 0.5g of Zn during its lifetime. It is therefore critical that the minerals are properly mixed into the diets. Particle size, particle size consistency, hygroscopicity, reactivity, and bulk density can influence mineral mixability. To assure proper mixing, a trace mineral product should contain particles that are ideally 150–250 microns in size with very little variation. This is critical to achieving a uniform mix and for maintaining trace mineral positional stability in final packaging. If particle size varies widely, smaller particles will segregate and move to the top or bottom of the package (bulk density dependent) when vibration occurs, such as during transport. A selected trace mineral should not be hygroscopic, which can chemically attract moisture into the trace mineral product or complete feed causing clumping and or destruction of essential nutrients in the premix or complete feed. The timing of when trace minerals are added to the mixing sequence and/or the total mixing time can adversely affect uniform distribution throughout the final feed. Compounding this challenge is a lack of precision typically offered by laboratory analysis. Samples of a mineral’s inclusion can range by 10-20% depending on the trace metal being measured. A good practice when sampling trace minerals within a mix is to avoid the first and last 10-15% of product discharged Figure 1. Vitamin E stability in feed - Source: Lu et al. Table 1. Trace metal concentration by product form Zinc sulfate Zinc oxide IntelliBond Z Zinc proteinate Zinc chelate Nano, zinc oxide Trace mineral form 25% 72% 55% 12-15% 15-28% 72% % metal (zinc) .32 kg TCF2 .11 kg TCF .15 kg TCF .67-.53 kg TCF .53-.29 kg TCF .11 kg TCF Amt. added per MT CF1 1Amount (kgs) added per Mt of a complete feed delivering 80 ppm zinc; 2Tons of complete feed
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