Vitamins from synthetic sources are permitted in organic diets for pigs.
A main concern for the nutritionist and feed manufacturer in selecting vitamins for inclusion in diets is their stability. In general, the fat-soluble vitamins are unstable (Combs, 1992) and they must be protected from heat, oxygen, metal ions and ultraviolet light. Antioxidants are frequently used in conventional feeds, to protect these vitamins from breakdown. All of the naturally occurring forms of vitamin A (retinol, retinal andβ-carotene) with the exception of retinoic acid are particularly unstable and sensitive to ultraviolet light, heat, oxygen, acids and metal ions. The naturally occurring forms of vitamin E (mainly tocopherols) are readily oxidized and destroyed by peroxides and oxygen in a process accelerated by PUFA and metal ions.
Because of the instabilities of their naturally occurring vitamers (forms of the vitamin), the concentrations of fat-soluble vitamins in natural foods and feedstuffs are highly variable, being greatly affected by the conditions of production, processing and storage. Consequently the synthetic esterified forms (acetate and palmitate), which are much more stable, are preferred for diet formulation.
Table 4.6. Concentrations of mineral elements in common dietary mineral sources.
Source IFN Formula Mineral
Concentration (%) Limestone, ground 6-02-632 CaCO3(mainly) Calcium 38
Calcium carbonate 6-01-069 CaCO3 Calcium 40
Oyster shell, ground 6-03-481 CaCO3 Calcium 38 Dicalcium phosphate 6-01-080 CaHPO4·2H2O Calcium 23
Phosphorus 18
Defluorinated phosphate
6-01-780 Calcium 32
Phosphorus 18
Phosphate, Curaçao 6-05-586 Calcium 36
Phosphorus 14
Salt, common 6-14-013 NaCl Sodium 39.3
Chloride 60.7
Copper sulphate CuSO4·5H2O Copper 25.4
Copper carbonate CuCO3·Cu(OH)2 Copper 55
Copper oxide CuO Copper 76
Calcium iodate Ca(IO3)2 Iodine 62
Potassium iodide KI Iodine 70
Ferrous sulphate FeSO4·H2O Iron 31
Ferrous sulphate FeSO4·7H2O Iron 21
Ferrous carbonate FeCO3 Iron 45
Manganous oxide MnO Manganese 77
Manganous sulphate MnSO4·H2O Manganese 32
Sodium selenite NaSeO3 Selenium 45
Sodium selenate NaSeO4 Selenium 41.8
Zinc oxide ZnO Zinc 80
Zinc sulphate ZnSO4·H2O Zinc 36
Zinc carbonate ZnCO3 Zinc 52
IFN, International Feed Number.
The bioavailability of the named minerals in the above forms is high or very high.
The exact concentration of minerals will vary, depending on the purity of the source.
The above sources may also provide trace amounts of minerals other than those listed, such as sodium, fluoride and selenium.
Cobalt-iodized salt is often used as a source of sodium, chloride, iodine and cobalt.
Other sources may be permitted in organic diets and producers should check with the local certifying agency for details. For instance, in the US regulations (FDA, 2001) the approved list of trace minerals with GRAS (Generally Recognized As Safe) status when added at levels consistent with good feeding practice includes those listed in Table 4.7.
Table 4.7. Trace minerals for use in animal feed approved by the US Food and Drug Administration.
Trace mineral Approved forms
Cobalt Cobalt acetate, carbonate, chloride, oxide, sulphate
Copper Copper carbonate, chloride, gluconate, hydroxide, orthophosphate, prophosphate, sulphate
Iodine Calcium iodate, iodobehenate; cuprous iodide; 3,5-diiodosalicylic acid; ethylenediamine dihydriodide; potassium iodate; potassium iodide; sodium iodate; sodium iodide
Iron Iron ammonium citrate; iron carbonate, chloride, gluconate, lactate, oxide, phosphate, pyrophosphate, sulphate; reduced iron
Manganese Manganese acetate, carbonate, citrate (soluble), chloride, gluconate, orthophosphate, phosphate (dibasic), sulphate;
manganous oxide
Zinc Zinc acetate, carbonate, chloride, oxide, sulphate
Vitamin D is available as D2 (ergocalciferol) and D3 (cholecalciferol).
Pigs can utilize either source but since poultry can utilize only the D3form it is usual to supplement all feeds (where necessary) with the D3form. Fish oil is allowed under the Canadian Feeds Regulations as a source of vitamins A and D.
The commonly available source of stable vitamin E used in animal feed is syntheticDL-α-tocopheryl acetate. An alternative form of stable vitamin E isD-α-tocopheryl acetate, which is derived from plant oils (such as soybean, sunflower and maize). This form has a relative biopotency of more than 136% in comparison withDL-α-tocopheryl acetate.
The potency of the fat-soluble vitamins is expressed in terms of international units (IU).
The water-soluble vitamins tend to be more stable under most practical conditions, exceptions being riboflavin (which is sensitive to light, heat and metal ions), pyridoxine (pyridoxal, which is sensitive to light and heat), biotin (which is sensitive to oxygen and alkaline conditions), pantothenic acid (which is sensitive to light, oxygen and alkaline conditions) and thiamin (which is sensitive to heat, oxygen, acidic and alkaline conditions, and metal ions) (Combs, 1992). Again, the more stable synthetic forms of these vitamins are used in conventional feed formulation. Choline chloride is very hygroscopic (absorbs water when exposed to air) and the non-hygroscopic choline bitartrate is a preferred source of this vitamin.
Vitamins allowed for addition to animal feeds under the Canadian Feeds Regulations (Class 7. Vitamin products) are listed below. All have to be labelled with a guarantee of declared potency.
7.1.1 p-Aminobenzoic acid (IFN 7-03-513).
7.1.2 Ascorbic acid (IFN 7-00-433), vitamin C.
7.1.23 Other forms of vitamin C.
7.1.24
7.1.25 7.1.30
7.1.3 Betaine hydrochloride (IFN 7-00-722), the hydrochloride of betaine.
7.1.4 D-Biotin (or Biotin,D-) (IFN 7-00-723).
7.1.5 CalciumD-pantothenate (IFN 7-01-079).
7.1.6 CalciumDL-pantothenate (IFN 7-17-904).
7.1.7 Choline chloride solution (IFN 7-17-881).
7.1.8 Choline chloride with carrier (IFN 7-17-900).
7.1.9 Fish oil (IFN 7-01-965), oil of fish origin used as a source of vitamins A and D.
7.1.10 Folic acid (or Folacin) (IFN 7-02-066).
7.1.11 Inositol (IFN 7-09-354).
7.1.12 Menadione and menaphthone in several forms (sources of vitamin K).
7.1.13 7.1.14 7.1.28 7.1.29
7.1.15 Niacin (or Nicotinic acid) (IFN 7-03-219).
7.1.16 Niacinamide (or Nicotinamide) (IFN 7-03-215), the amide of nicotinic acid.
7.1.17 Pyridoxine hydrochloride (IFN 7-03-822).
7.1.18 Riboflavin (IFN 7-03-920).
7.1.19 Riboflavin-5'-phosphate sodium (IFN 7-17-901), the sodium salt of the phosphate ester of riboflavin.
7.1.20 Thiamin hydrochloride (IFN 7-04-828).
7.1.21 Thiamin mononitrate (IFN 7-04-829).
7.1.22 Vitamin B12(IFN 7-05-146), cyanocobalamin.
7.1.26 Choline bitartrate (IFN 7-18-674), a non-hygroscopic source of choline containing 46.9% choline.
7.1.27 Betaine, anhydrous (or Betaine) (IFN 7-32-193).
7.1.31 Vitamin A (IFN 7-05-142), the acetate ester, palmitate ester, propionate ester or a mixture of these esters of retinol formulated in an organic matrix.