How is a compound trace element premix formula designed? Scientific Pig Farming Q&A 42
For example: To design a trace element additive premix formula for the basal diet of growing-finishing pigs weighing 60-90 kg, the steps are as follows:
1. Consult the latest national feeding standard for lean-type growing-finishing pigs. From it, the trace element requirements of growing-finishing pigs weighing 60-90 kg are as follows: iron 50 mg/kg diet, zinc 90 mg/kg diet, copper 3.75 mg/kg diet, manganese 2.50 mg/kg diet, iodine 0.14 mg/kg diet, selenium 0.10 mg/kg diet.
2. Consult the feed composition table, and calculate the content of each trace element based on the feed types in the existing basal diet formula. It is now assumed that the corresponding contents of each trace element in this basal diet are as follows: iron 30 mg/kg air-dried diet, zinc 60 mg/kg air-dried diet, copper 2.75 mg/kg air-dried diet, manganese 1.50 mg/kg air-dried diet, iodine 0.04 mg/kg air-dried diet, selenium 0.05 mg/kg air-dried diet.
3. Calculate the amount of each trace element that needs to be added:
Requirement - content in basal diet = amount to be added
Iron: 50-30=20
Zinc: 90-60=30
Copper: 3.75-2.75=1.00
Manganese: 2.50-1.50=1.00
Iodine: 0.14-0.04=0.10
Selenium: 0.10-0.05=0.05
4. Select suitable trace element additive raw materials. Based on the molecular formula, calculate the percentage content and coefficient of the elements iron, copper, manganese, zinc, iodine and selenium (the coefficient is the molecular weight of the compound divided by the multiple of that element). For example, ferrous sulfate contains 7 water molecules of crystallization, with the molecular formula FeSO4·7H2O. Consult Mendeleev's periodic table of chemical elements; the atomic weights of the elements are as follows:
FeS04·7H2O，
Atomic weight of iron = 56
Atomic weight of sulfur = 32
Atomic weight of oxygen = (16×4) = 64
Atomic weight of 7 water molecules = (1×2+16)×7 = 126
Total: 56+32+64+126=278
Percentage content of the iron element in the ferrous sulfate compound = 56/278=20.1%
At the same time, look up their purity (%) as listed below:
Ferrous sulfate molecular formula: FeSO4·7H2O, Fe element content 20.10%, coefficient 4.98, purity 98.5%;
Copper sulfate molecular formula CuSO4·5H2O, Cu element content 25.50%, coefficient 3.92, purity 96.0%;
Manganese sulfate molecular formula MnSO4·H2O, Mn element content 32.90%, coefficient 3.04, purity 98.0%;
Zinc sulfate molecular formula ZnSO4·5H2O, Zn element content 22.70%, coefficient 4.41, purity 98.0%;
Potassium iodide molecular formula KI, I element content 76.40%, coefficient 1.31, purity 98.0%;
Sodium selenite molecular formula NaSeO3·5H2O, Se element content 30.00%, coefficient 3.33, purity 95.0%.
Note: coefficient = molecular weight of ferrous sulfate / Fe atomic weight = 278/56 = 4.96
If calculated on the basis of Fe element accounting for 20.1%, coefficient = 100/20.1 = 4.975 = 4.98
If calculated on the basis of Cu element accounting for 25.5%, coefficient = 100/25.50 = 3.92
5. Convert the trace elements that should be added into the corresponding weight of pure compound raw material (pure raw material weight = amount to be added × conversion coefficient = 20×4.98 = 99.60 mg/kg diet) as follows:
The amount of iron to be added is 20 mg/kg diet, conversion coefficient 4.98, pure raw material weight 99.60 mg/kg diet;
The amount of zinc to be added is 30 mg/kg diet, conversion coefficient 4.41, pure raw material weight 132.30 mg/kg diet;
The amount of copper to be added is 1.00 mg/kg diet, conversion coefficient 3.92, pure raw material weight 3.92 mg/kg diet;
The amount of manganese to be added is 1.00 mg/kg diet, conversion coefficient 3.04, pure raw material weight 3.04 mg/kg diet;
The amount of iodine to be added is 0.10 mg/kg diet, conversion coefficient 1.31, pure raw material weight 0.131 mg/kg diet;
The amount of selenium to be added is 0.05 mg/kg diet, conversion coefficient 3.33, pure raw material weight 0.167 mg/kg diet.
6. Convert the pure raw material weight into the weight of commercially available commercial raw material:
Corresponding commercial raw material amount = corresponding pure raw material amount / corresponding commercial raw material purity × 100 = 99.6/98.5×100 = 101.12
For the added element iron, corresponding pure raw material amount 99.60 mg, corresponding commercial raw material purity 98.5%, corresponding commercial raw material amount 101.12 mg;
For the added element zinc, corresponding pure raw material amount 132.30 mg, corresponding commercial raw material purity 98%, corresponding commercial raw material amount 135.00 mg;
For the added element copper, corresponding pure raw material amount 3.92 mg, corresponding commercial raw material purity 96%, corresponding commercial raw material amount 4.08 mg;
For the added element manganese, corresponding pure raw material amount 3.04 mg, corresponding commercial raw material purity 98%, corresponding commercial raw material amount 3.10 mg;
For the added element iodine, corresponding pure raw material amount 0.131 mg, corresponding commercial raw material purity 98%, corresponding commercial raw material amount 0.13 mg;
For the added element selenium, corresponding pure raw material amount 0.167 mg, corresponding commercial raw material purity 95%, corresponding commercial raw material amount 0.18 mg.
7. Determine the dosage of this premix to be used, and calculate the amount of carrier. It is now determined that the usage amount of this premix is 1%, that is, 1% of the total feed amount. From step six, it is known that the total amount of commercial raw materials of the several elements is 101.12+135.0+4.08+3.10+0.13+0.18=243.61 mg, so the carrier amount is 10-0.24361=9.75639, that is, the added amount per kilogram of feed is 10 g, and 9.75639 of this premix is carrier.
8. Select a suitable carrier. It is now determined to use light calcium carbonate powder as the carrier.
9. That is, the premix formula (as follows)
After listing the premix formula, the formula should be annotated, noting that it is a compound trace element premix additive suitable for growing-finishing pigs weighing 60-90 kg, explaining that this formula product should be mixed evenly with feed at a ratio of 1% before use, and finally the technical supervisor signs and writes the year, month and day.
Trace element additive premix formula for growing-finishing pigs weighing 60-90 kg:
Ferrous sulfate 101.12 mg, 1.01%, required amount for producing 100 kg of premix 1.01 kg;
Zinc sulfate 135.00 mg, 1.35%, required amount for producing 100 kg of premix 1.33 kg;
Copper sulfate 4.08 mg, 0.041%, required amount for producing 100 kg of premix 41 g;
Manganese sulfate 3.10 mg, 0.031%, required amount for producing 100 kg of premix 31 g;
Potassium iodide 0.13 mg, 0.001%, required amount for producing 100 kg of premix 1 g;
Sodium selenite 0.18 mg, 0.002%, required amount for producing 100 kg of premix 2 g;
Carrier (light calcium carbonate) 9956.39 mg, 97.564%, required amount for producing 100 kg of premix 97.564 kg;
Total 100 kg.
According to the above premix formula, weigh out in sequence the commercial raw materials ferrous sulfate 1.01 kg, zinc sulfate 1.33 kg…… carrier 97.564 kg, mix evenly to make 100 kg. This is the trace element additive premix for finishing pigs weighing 60-90 kg. (This content is excerpted from "100 Questions and Answers on Scientific Pig Farming", compiled and printed by the Yingtan Association of Old Science and Technology Workers, authored by Zhang Genkai.)
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