Introduction
Chemical composition of the food, the biosphere and physical environment in its surroundings are the main factors that influence quality of life. The natural ecosystem is supposed to be a fundamental system consisting of the community of all living organisms in an environment having a balanced cycle of chemical elements and energy flow. But the ecosystem has already been considerably modified and such modifications continue.
India occupies 2.4% of the world’s geographical area with a large percentage of its land under agriculture however, availability of feed and fodder remain insufficient to meet requirement of growing animal population. Livestock sector is the best and most effective tool for livelihood security and poverty alleviation. Nutrition and reproduction are two important factors that affect the production performance of the animal. Proper reproductive health and good plane of nutrition helps in increasing the milk production of an animal, which is the prime intention of the farmer.
All living things require minimum amounts of certain essential elements with known biological roles and functions to maintain optimal health and productivity. There is always an optimal concentration of essential elements required by organisms; above or below the optimal range, in which a toxicity or deficiency state in a system may compromise health, quality and productivity. Minerals are chemical constituents used by the body in many ways.
Minerals are one of the important nutritional components having significant role in the health, production, reproduction and immune defense of the animals. Minerals are required by the body for optimum growth and proper muscle and nerve functions. In addition they are essential components of body enzymes, hormones and cells. Mineral deficiencies or imbalance in soil and forages are responsible for low productivity problems among growing cattle in tropics. The mineral profile of feeds and fodder depends upon the cropping pattern, soil type, rainfall and feeding system of that particular region of the country depending on the agro-climatic zones. Thus, deficiency and surplus of a particular mineral varies between different regions of the country and may be called as area- specific. Dietary factors usually affect mineral requirement by altering absorption of minerals from the gut. Certain macrominerals are required in large quantities and include calcium, chloride, magnesium, phosphorous, potassium, sodium and sulphur and cobalt, copper, iodine, iron, manganese, molybdenum, selenium and zinc are required in smaller quantities and thus are microminerals.
Functions of different Minerals in body
Calcium and phosporus are required in relatively large quantities by cattle and they are closely related in the metabolism of the animal. The ratio of these two minerals recommended in the ration as most desirable is 1 to 2 parts of calcium to 1 part of phosphorus. The bones serve as a storehouse for calcium and phosphorus and if the ration contains inadequate amounts, they can be withdrawn from the bones to supply other needs. Thus a deficiency of calcium and-or phosphorus result in weak and improperly developed bones. When carried to an advanced stage, it is called “rickets” in the young animal and “osteomalcia” in the adult. These diseases are characterized by stiffness, swollen joints, bent knees and arched back. Calcium functions as a constituent of bones and teeth, regulation of nerve and muscle function. In blood coagulation, calcium activates the conversion of prothrombin to thrombin and also takes part in milk clotting. It plays a vital role in enzyme activation. Calcium activates large number of enzymes such as adenosine triphosphatase (ATPase), succinic dehydrogenase, lipase etc. It is also required for membrane permeability, involved in muscle contraction, normal transmission of nerve impulses and in neuromuscular excitability.
Copper functions in the utilization of iron in an early stage of haemopoiesis. Copper deficiency results in an increase in iron in the liver, whereas an excesss of copper results in a decrease in iron content of the liver, thus reflecting the role of copper in iron utilization. Copper is present in blood plasma as a copper-carrying plasma protein called erythrocuprin.
Sodium is the principal cation in extracellular fluids. It regulates plasma volume and acid-base balance, involved in the maintenance of osmotic pressure of the body fluids, preserves normal irritability of muscles and cell permeability, activates nerve and muscle function and involved in Na + /K + -ATPase, maintenance of membrane potentials, transmission of nerve impulses and the absorptive processes of monosaccharides, amino acids, pyrimidines, and bile salts.
Chlorine is involved in fluid and electrolyte balance, gastric fluid and chloride shift in HCO3 – transport in erythrocytes. Chloride is the principal anion in extracellular fluid. It is involved in the regulation of extracellular osmotic pressure and makes up over 60% of the anions in this fluid compartment and is thus important in acidbase balance.
Magnesium is an active component of several enzyme systems in which thymine pyrophosphate is a cofactor. Oxidative phosphorylation is greatly reduced in the absence of magnesium. Magnesium is also an essential activator for the phosphate-transferring enzymes myokinase, diphophopyridinenucleotide kinase, and creatine kinase. It also activates pyruvic acid carboxylase, pyruvic acid oxidase, and the condensing enzyme for the reactions in the citric acid cycle. It is also a constituent of bones, teeth, enzyme cofactor, (kinases, etc).
Chromium is an essential element for animals. It plays a role in maintaining the configuration of the RNA molecule, because chromium has been shown to be particularly effective as a cross-linking agent for collagen. Chromium has also been identified as the active ingredient of the glucose tolerant factor a dietary factor required to maintain normal glucose tolerance.
Cobalt is required as a constituent of vitamin B12 and its metabolism is the same as for vitamin B12. In addition to its role in vitamin B12, cobalt is also a cofactor of enzymes involved in DNA biosynthesis and amino acid metabolism. In cattle and sheep, bacteria in the rumen can use metallic Cobalt to synthesize vitamin B12 and are thus the ultimate source of the vitamin.
Iodine is a basic component of the thyroid hormones, thyroxine and mono-, di-, and tri-iodothyronine and it is stored in thyroid as thyroglobulin. A deficiency of iodine can be prevented by feeding stabilized iodized salt to animals or in poultry by supplementing the feed with as little as 0.35 mg/kg of iodine.
Iron functions as haemoglobin in the transport of oxygen. In cellular respiration, it functions as essential component of enzymes involved in biological oxidation. Iron is an important constituent of succinate dehydrogenase as well as a part of the haeme of haemoglobin (Hb), myoglobin and the cytochromes. Iron is required for proper myelination of spinal cord and white matter of cerebellar folds in brain and is a cofactor for a number of enzymes involved in neurotransmitter synthesis. Iron is involved in synthesis and packaging of neurotransmitters, their uptake and degradation into other iron-containing proteins which may directly or indirectly alter brain function.
Manganese is involved in glycoprotein and proteoglycan synthesis and is a component of mitochondrial superoxide dismutase. Manganese is a co-factor in phosphohydrolases and phosphotransferases involved in the synthesis of proteoglycans in cartilage. Manganese is a part of enzymes involved in urea formation, pyruvate metabolism and the galactotransferase of connective tissue biosynthesis. Manganese activates several important enzyme systems and in this capacity it is required for the synthesis of acid mucopolysaccharides, such as chondroitin sulphate, to form the matrices of bones and egg shells.
Selenium is an important constituent element of the entire defence system that protects the living organism from the harmful action of free radicals. Organic selenium is more thoroughly resorbed and more efficiently metabolized than its inorganic equivalent, which is poorly resorbed and acts more as a prooxidant provoking glutathione oxidation and oxidative damage to the DNA.
Molybdenum is a component of several metalloenzyme including xanthine oxidase, aldehyde oxidase, nitrate reductase, and hydrogenase. Xanthine oxidase and aldehyde oxidase play a role in iron utilization as well as in cellular metabolism in electron transport. It is readily absorbed from foods. Molybdenum is an important micronutrient both in animal and plant nutrition. In plants, it plays a role in nitrogen fixation and nitrate assimilation through nitrate reductase which is a key enzyme in the metabolic process in leguminous plants.
Flourine increases hardness of bones and gives strength to the enamel tissues of the teeth. It is also essential for rat growth. It plays a role in the prevention and treatment of dental caries. Fluoride in saliva reduces cavities by reducing acid produced by bacteria and by increasing enamel remineralization after acid exposure. Fluoride has great affinity for calcium and so it is associated with calcification of bones and teeth.
Zinc functions in the immune system through energy production, protein synthesis, stabilization of membranes against bacterial endotoxins, antioxidant enzyme production, and maintenance of lymphocyte replication and antibody production. Zinc deficiency has been shown to have an important impact on immunity. Thus, mineral elements are required for all physiological functions, and support optimal growth, health condition, the immune system, productivity and reproduction. An inadequate supply of minerals will lead to a deficiency and cause biochemical dysfunction, disturbed physiological functions or structural disorders.
Dr. Pallavi Khajuria, Dr. Gurpreet Singh and Dr. Gagandeep Singh
1 Assistant Professor, 2 Associate Professor, 3 Assistant Professor
Department of Veterinary Physiology and Biochemistry
Department of Veterinary Medicine
College of Veterinary Science, Rampura Phul
Guru Angad Dev Veterinary and Animal Sciences University