Chelates in animal nutrition
Encyclopedia
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
, manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
.
The animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s absorb,digest and use mineral chelates better than inorganic minerals. This means that lower concentrations can be used in animal feeds. In addition, animals fed chelated sources of essential trace minerals excrete lower amounts in their feces and so there is less environmental contamination. Mineral chelates also offer health and welfare benefits in animal nutrition
Animal nutrition
There are seven major classes of nutrients: carbohydrates, fats, fiber, minerals, protein, vitamin, and water.These nutrient classes can be categorized as either macronutrients or micronutrients . The macronutrients are carbohydrates, fats, fiber, proteins, and water...
Brief History of Chelates
Since the 1950s, animal feeds have been supplemented with essential trace minerals such as copper (Cu), iron (Fe), iodineIodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
(I), manganese (Mn), molybdenum
Molybdenum
Molybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
(Mo), selenium
Selenium
Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...
(Se) and zinc (Zn). Initially, such supplementation was by means of inorganic salts of essential trace elements. From the 1960s onwards, genetic improvement of farm livestock resulted in increased nutritional requirements for these nutrients. Chelated minerals were developed in the 1980s and 1990s. Trace mineral chelates have proven to be better than inorganic minerals in meeting the nutritional needs of modern farm animals.
Role and source of minerals
The objective of supplementation with trace minerals is to avoid a variety of deficiency diseases. Trace minerals carry out key functions in relation to many metabolic processesMetabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
, most notably as catalysts for enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s and hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
s, and are essential for optimum health, growth and productivity. For example, supplementary minerals help ensure good growth, bone development, feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
ing in birds, hoof
Hoof
A hoof , plural hooves or hoofs , is the tip of a toe of an ungulate mammal, strengthened by a thick horny covering. The hoof consists of a hard or rubbery sole, and a hard wall formed by a thick nail rolled around the tip of the toe. The weight of the animal is normally borne by both the sole...
, skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
and hair
Hair
Hair is a filamentous biomaterial, that grows from follicles found in the dermis. Found exclusively in mammals, hair is one of the defining characteristics of the mammalian class....
quality in mammals, enzyme structure and functions, and appetite. Deficiency of trace minerals affect many metabolic processes and so may be manifested by different symptoms, such as poor growth and appetite
Appetite
The appetite is the desire to eat food, felt as hunger. Appetite exists in all higher life-forms, and serves to regulate adequate energy intake to maintain metabolic needs. It is regulated by a close interplay between the digestive tract, adipose tissue and the brain. Decreased desire to eat is...
, reproductive failures, impaired immune responses, and general ill-thrift. From the 1950s to the 1990s most trace mineral supplementation of animal diets was in the form of inorganic minerals, and these largely eradicated associated deficiency diseases in farm animals.
The role in fertility
Fertility
Fertility is the natural capability of producing offsprings. As a measure, "fertility rate" is the number of children born per couple, person or population. Fertility differs from fecundity, which is defined as the potential for reproduction...
and reproductive diseases of dairy cattle
Dairy cattle
Dairy cattle are cattle cows bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cows generally are of the species Bos taurus....
highlights that organic forms of Zn are retained better than inorganic sources and so may provide greater benefit in disease prevention, notably mastitis
Mastitis
Mastitis is the inflammation of breast tissue. S. aureus is the most common etiological organism responsible, but S. epidermidis and streptococci are occasionally isolated as well.-Terminology:...
and lameness
Lameness (equine)
Lameness in horses and other equidae is a term used to refer to any number of conditions where the animal fails to travel in a regular and sound manner on all four feet...
Sources of essential minerals
In this decades, global food animal production has intensified and genetic potential for growth and yields has improved. As a result commercial tendencies have been to increase trace mineral supplementation,in order to allow for the greater mineral requirements of superior stock reared under industrial conditions. Increasing the concentration of inorganic minerals in animal diets has led to several problems.The use of high Cu in swine and poultry
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...
rations has caused accidental Cu poisoning in more sensitive animals, such as sheep grazing pastures fertilised with pig or poultry manure
Manure
Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...
SCAN (2003a) Opinion of the Scientific Committee for Animal Nutrition on the use of copper in feedingstuffs]. Secondly, inorganic minerals may form insoluble complexes with other dietary agents resulting in low absorption. In addition, it is thought that the positive charge of many inorganic minerals reduces access to the enterocyte
Enterocyte
Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells found in the small intestines and colon. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase surface area for the digestion and transport of molecules from the intestinal...
s due to repulsion by the negatively charged mucin
Mucin
Mucins are a family of high molecular weight, heavily glycosylated proteins produced by epithelial tissues in most metazoans. Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell...
layer and competition for binding sites.
Finally, the poor retention and high excretion
Excretion
Excretion is the process by which waste products of metabolism and other non-useful materials are eliminated from an organism. This is primarily carried out by the lungs, kidneys and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell...
rates of inorganic minerals led to environmental concerns during the 1980s and 1990s, especially in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.Opinion of the Scientific Committee for Animal Nutrition on the use of zinc in feedingstuffs]. The European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
is concerned about possible detrimental effects of excess supplementation with trace minerals on the environment or human and animal health, and so in 2003 legislated a reduction in permitted feed concentrations of several trace metal
Trace metal
Trace metals are metals in extremely small quantities that reside in or are present in animal and plant cells and tissue. They are a necessary part of good nutrition, although they can be toxic if ingested in excess quantities....
s (Co, Cu, Fe, Mn and Zn).
Research in trace element nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....
has led to the development of more bioavailable organic minerals, including trace minerals derived from chelates. Chelates allow a lower supplementation rate of trace minerals with an equivalent or improved effect on animal health, growth and productivity . Some samples of natural minerals at the Wikimedia Commons:
Particular types of Chelates
They are in summary;- Chelates, are organic molecules, normally consisting of 2 organic parts with an essential trace mineral occupying a central position and held in place by covalent bondCovalent bondA covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding....
ing. - Proteinate, are a particular type of chelate, in which the mineral is chelated with short-chain peptidePeptidePeptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
s and amino acidAmino acidAmino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s derived from hydrolysed soy proteinsHydrolyzed proteinHydrolyzed protein is protein that has been hydrolyzed or broken down into its component amino acids. While there are many means of achieving this, two of the most common are prolonged boiling in a strong acid or strong base or using an enzyme such as the pancreatic protease enzyme to stimulate...
,. In proteinates, minerals are bound to various amino acids with different levels of stability - Amino-acid complex, such as glycinates or methionates, are other particular types of chelate, in which the mineral is chelated with an amino acid. Based on one single type of amino-acid, the product is pure (there is only one type of bond or chelation between minerals and the ligand) and it is therefore easier to work on stability and ensure a full chelation. Moreover, depending on the size of amino acid, it is also possible to increase the metal content
Research
Some notice concluded that the utilisation of organic Cu from a copper chelate or copper lysine were higher than that of inorganic Cu sulfate when fed to rats in the presence and absence of elemental Zn or Fe. The data suggest that, unlike inorganic Cu, organic Cu chelates exhibit absorption and excretion mechanisms that do not interfere with Fe. Copper chelate also achieved higher liver Zn, suggesting less interference at gut absorption sites in comparison with the other forms of CuEffect of organic zinc sources on performance, zinc status and carcass, meat and claw quality in fattening bulls. Livestock Prod. Sci. 81:161-171. compared a Zn chelate, a Zn polysaccharide
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
complex and ZnO (inorganic zinc oxide
Zinc oxide
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
) in bull beef cattle
Beef cattle
Beef cattle are cattle raised for meat production . The meat of cattle is known as beef. When raised in a feedlot cattle are known as feeder cattle. Many such feeder cattle are born in cow-calf operations specifically designed to produce beef calves...
, and concluded that the organic forms resulted in some improvement in hoof claw quality.
Compared the bioavailability
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...
of Cu and Zn chelates in sheep with the inorganic sulfate forms, at "low" and "high" supplementation rates. Copper and Zn chelates at the lower rates caused significantly greater increases in blood plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
concentrations than the corresponding treatments with Zn sulfate (p<0.05) and Cu sulfate (p<0.01).
In addition, Zinc chelate supplementation resulted in significantly greater hoof horn Zn content than did Zn sulfate (p<0.05). At the "low" supplementation rate Zinc chelate achieved better hoof quality than Zn sulfate (p<0.05). The data suggest that Cu and Zn chelates are more readily absorbed and more easily deposited in key tissues such as hooves, in comparison with inorganic Zn forms.
In weaned piglets evaluated various supplementation rates of organic Zn in the form of a chelate or as a polysaccharide complex and compared these with ZnO ,zinc oxide, at 2,000 ppm. Feeding lower concentrations of organic Zn greatly decreased the amount of Zn excreted in comparison with inorganic Zn, without loss of growth performance.
Studied a Copper chelate in weaned pigs in comparison with inorganic Cu and sulfate. Piglet performance was consistently better with organic Cu at 50 to 100 ppm, in comparison with inorganic Cu at 250 ppm. In addition, organic Cu increased Cu absorption and retention, and decreased Cu excretion 77% and 61% respectively, compared with 250 ppm inorganic Cu
The effects of an Mg chelate in broiler chickens in comparison with magnesium oxide
Magnesium oxide
Magnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...
and an unsupplemented control group. Diets for fattening chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...
are not normally supplemented with Mg, but this study indicated positive effects on performance and meat quality. During the first 3 weeks of life, the Mg chelate improved feed efficiency significantly in comparison with both the inorganic MgO and the negative control group (p<0.05). Thigh meat pH and oxidative deterioration during storage were also studied. The Mg chelate increased thigh meat pH in comparison with the negative control (p<0.05). Mg supplementation significantly reduced chemical indicators (TBARS) of oxidative deterioration in liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
and thigh muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
(p<0.01), with Mg chelate significantly more efficient than MgO (p<0.01). The data suggest that organic Mg in the form of a chelate is capable of reducing oxidation, and so improve chicken meat quality
A Zn chelate supplement was compared with Zn sulfate in broiler chickens.Weight gain and feed intake increased quadratically (p<0.05) with increasing Zn concentrations from the chelate and linearly with Zn sulfate. The relative bioavailability of the Zn chelate was 183% and 157% of Zn sulfate for weight gain and tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
Zn, respectively. The authors concluded that the supplemental concentration of Zn required in corn-soy diets for broilers from 1–21 days of age would be 9.8 mg/kg diet as Zn chelate and 20.1 mg/kg diet as Zn sulfate,respectively.
The effect of replacing inorganic minerals with organic minerals in broiler chickens. One group of chickens received inorganic sulfates of Cu (12 ppm), Fe (45 ppm), Mn (70 ppm) and Zn (37 ppm) and their performance was compared to a similar group supplemented with chelates of Cu (2.5 ppm), Fe, Mn, and Zn (all at 10 ppm).
There were no differences in performance between the birds fed the high inorganic minerals and the birds fed the low organic chelates. Faecal concentrations of Cu, Fe, Mn and Zn were 55%, 73%, 46% and 63%, respectively, of control birds fed inorganic minerals.
A broiler study reported also compared inorganic and organic mineral supplementation in broiler chickens. Control birds were fed Cu, Fe, Mn Se and Zn in inorganic forms (15 ppm Cu 15 from sulfate; 60 ppm Fe from sulfate etc),and compared with three treatment groups supplemented with organic forms. Apart from improved feathering, most likely associated with the presence of organic Se, there were no significant performance differences between birds fed inorganic and organic minerals. The authors concluded that the use of organic trace minerals permits a reduction of at least 33% in supplement rates in comparison with inorganic minerals, without compromising performance .