1. Trace Mineral Requirements Beef CattleSheepHorses ElementReqmtMax.ReqmtMax.ReqmtMax. Co, ppm0.10100.10-0.20100.0525 Cu, ppm10-151007-112510250 I, ppm0.50500.10-0.80500.35-0.405 Fe, ppm501,00030-5050040-50500 Mn, ppm20-401,00020-401,00040400 Mo, ppmNA50.510NA20-100 Se, ppm0.1020.10-0.2020.102 Zn, ppm30-4050020-3375040500

2. Mineral Requirements Given as concentration required in the total diet DM Includes all the ingredients the animal is consuming

3. Mineral Requirements Sheep are more sensitive to Cu toxicity than are cattle or horses Do not feed a mineral supplement formulated for cattle or horses to sheep

5. Example Calculation A cow is consuming: 30 lbs of alfalfa/grass hay (90% DM; 7 ppm Cu) 4 oz of commercial trace mineral mix (97% DM; 500 ppm Cu)

6. Calculate Cu Supply – Hay Hay: 30 lbs x 0.90 = 27 lbs DM 27 lbs DM x 0.454 kg/lb = 12.26 kg DM 12.26 kg DM x 7 ppm (or 7 mg/kg) = 85.8 mg Cu from hay

7. Calculate Cu Supply – TM mix Mineral mix: 4 oz x 0.97 = 3.9 oz DM 3.9 oz DM x 28 g/oz = 109.2 g DM 109.2 g DM /1,000 = 0.109 kg DM 0.109 kg x 500 ppm (or 500 mg/kg) = 54.5 mg Cu from mineral mix

8. Calculate Cu Supply – Total Total Cu in the diet: 85.8 mg + 54.5 mg = 140.3 mg Total DM intake by cow: 12.26 kg hay + 0.109 kg mineral mix = 12.37 kg 140.3 mg Cu/12.37 kg DM intake = 11.3 mg/kg Cu (or 11.3 ppm Cu)

9. Trace Mineral Requirements Beef CattleSheepHorses ElementReqmtMax.ReqmtMax.ReqmtMax. Co, ppm0.10100.10-0.20100.0525 Cu, ppm 10-15100 7-112510250 I, ppm0.50500.10-0.80500.35-0.405 Fe, ppm501,00030-5050040-50500 Mn, ppm20-401,00020-401,00040400 Mo, ppmNA50.510NA20-100 Se, ppm0.1020.10-0.2020.102 Zn, ppm30-4050020-3375040500

10. Evaluate Cu Supply If “look at” Cu analysis of hay: 7 ppm vs. 10-15 ppm requirement Wrongly conclude DEFICIENT If “look at” Cu on supplement tag: 500 ppm vs. 100 ppm maximum Wrongly conclude TOXIC