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TAMIL NADU VETERINARY AND ANIMAL SCIENCES UNIVERSITY ANIMAL NUTRITION THEORY LECTURE NOTES (As per Veterinary Council of India Minimum Standards of Veterinary Education- (Bachelor of Veterinary Science and Animal Husbandry - Degree Course) Regulations, 2016) UNIT-1 (PRINCIPLES OF ANIMAL NUTRITION AND FEED TECHNOLOGY) Author: Dr. J. Ramesh, M.V.Sc., PhD., Assistant Professor & Dr.R.Karunakaran, M.V.Sc., PhD., Professor and Head DEPARTMENT OF ANIMAL NUTRITON MADRAS VETERINARY COLLEGE CHENNAI - 600 007 2020 ANIMAL NUTRITION 3 + 1 ANIMAL NUTRITION THEORY LECTURE NOTES UNIT - 1 (PRINCIPLES OF ANIMAL NUTRITION AND FEED TECHNOLOGY) History of animal nutrition. Importance of nutrients in animal production and health. Composition of animal body and plants. Nutritional terms and their definitions. Nutritional aspect of carbohydrates, protein and fats. Role and requirement of water, metabolic water. Importance of minerals (major and trace elements) and vitamins in health and production, their requirements and supplementation in feed. Common feeds and fodders, their classification, availability and importance for livestock and poultry production. Measures of food energy and their applications - gross energy, digestible energy, metabolizable energy, net energy, total digestible nutrients, starch equivalent, food units, physiological fuel value. Direct and indirect calorimetry, carbon and nitrogen balance studies. Protein evaluation of feeds - Measures of protein quality in ruminants and non-ruminants, biological value of protein, protein efficiency ratio, protein equivalent, and digestible crude protein. Calorie protein ratio. Nutritive ratio. Introduction to feed technology- Feed industry; Processing of concentrates and roughages. Various physical, chemical and biological methods for improving the nutritive value of inferior quality roughages. Preparation, storage and conservation of livestock feed through silage and hay and their uses in livestock feeding. Harmful natural constituents and common adulterants of feeds and fodders. Feed additives in the rations of livestock and poultry and their uses Animals are such agreeable friends - they ask no questions, they pass no criticism - George Eliot IMPORTANCE OF NUTRIENTS IN ANIMAL PRODUCTION AND HEALTH The efficiency of animal production depends on genetic makeup of animal, nutritional status of animal and management practices. Nutrition plays a pivotal role in animal production and health as: a) It brings out the genetic potentiality of the animal. For example, even if a cow has a capacity of producing 25 litres of milk per day genetic makeup, the cow cannot produce 25 litres of milk per day if it is under fed. b) It makes the animal production economical as the cost of feeding of animals accounts for 70-75 % of total animal production cost. c) It minimizes the competition between human and animal for food by introducing non - conventional feeds for animal feeding. d) It manipulates feed ingredients for effective utilization of nutrients. LESSON 1: COMPOSITION OF ANIMAL BODY AND PLANTS Plants synthesize complex substances from simple substances like Co 2, N, H20 etc making use of solar energy. They use carbon dioxide from the air, water and other inorganic salts from the soil to synthesize carbohydrates, proteins and fat. Animals ingest these plants and utilize this energy for their bodily functions, tissue growth and production of products. An important constituent of the animal or plant body is water. The dry matter in both plants and animals is made up of organic and inorganic matter. Organic matter comprises mainly of three important nutrients namely carbohydrates, proteins and fat. Some minor constituents of organic matter are vitamins, nucleic acids and others. Inorganic matter is made up of various minerals. Composition of animal body The composition of animal body is affected by species, strain, age, sex and state of nutrition. Species The % composition of animal body As such or fresh matter basis water and fat free basis Water Protein Fat Ash Protein Ash Calf (new born) 74 19 3 4.1 82.2 17.8 Calf (fat) 68 18 10 4.0 81.6 18.4 Steer (thin) 64 19 12 5.1 79.1 20.9 Steer (fat) 43 13 41 3.3 79.5 20.5 Sheep (thin) 74 16 5 4.4 78.2 21.8 Sheep (fat) 40 11 46 2.8 79.3 20.7 Pig (8 kg) 73 17 6 3.4 83.3 16.7 Pig (30 kg) 60 13 24 2.5 84.3 15.7 Pig (100 kg) 49 12 36 2.6 82.4 17.6 Hen 56 21 19 3.2 86.8 13.2 Horse 61 17 17 4.5 79.2 20.8 Man 59 18 18 4.3 80.7 19.3 Water Water content of animal body is variable and decreases as age increases. For example, cattle embryo contains 95 % water, new born calf contains 75-80 % water, 5 months old calf contains 66-72 % water and mature animal contains 50-70 % water. The distribution of water within the body is not uniform. Blood plasma contains 90 - 92 %, heart, kidney and lungs – 80%; muscles – 75%, bones – 45% and tooth enamel only 5 % water. Water content of animal body also depends on nutritional status of the animal. Fat Fat is the most variable of all components. Fat content of animal body increases with age. Fat is usually found in adipose tissues, which is present under the skin, around kidney, around intestine and other internal organs. Protein It is the major constituent of dry matter in muscles, soft tissue, liver, heart, kidney, lungs, intestines, etc. Muscles contain nearly 75-80 % protein. Protein is also present in hair, nails, feathers, hooves, skin, wool, tendons and bones. Protein along with some inorganic elements is responsible for the structure of the animals. Carbohydrate It is present only around 1 % of the total animal body. It is being constantly formed and broken down and serves a multitude of functions. It is usually present as glucose or glycogen in liver and muscles. Inorganic elements Animal body contains many a minerals. The amount of mineral in animal body varies which depend on the function of the particular part of the body. Concentration of some minerals in animal body is as follows: Calcium - 1.3 % Phosphorus - 0.7 % Sodium - 0.16 % Potassium - 0.19 % Magnesium - 0.04 % Sulphur - 0.15 % Calcium is the mineral that that occurs in largest amount in the body and is almost entirely present in bones and teeth. Phosphorus is present in bones in close association with calcium. Phosphorus is also present in association with proteins, fats and other inorganic salts. Na, K and Cl are present in inorganic form in various fluids. Other minerals form component of tissues fluids or enzymes. Composition of individual tissues Blood forms 5-10 % of body weight. 90 % of it is water and 10 % is solids. Nearly 50 % of the solid content of blood is protein and other nutrients in blood present are fatty substances, sugar, amino acids, NPN and inorganic salts. Muscles contain around 75 % water. The 25 % DM comprises of 75 % protein and the rest is fat, carbohydrates and inorganic matter. In epithelial tissues (skin, hair, feathers, etc) the protein is predominantly keratin. In connective tissues (bone, collage, ligaments), the protein is predominantly collagen. How to estimate animal body composition? 1. Slaughtering the animal and analysing the carcass 2. Radio Isotope studies – using tracer techniques 3. Magnetic Resource imaging Composition of plants The composition of plants shows wide variations. The principal constituent of living plants is moisture. The moisture content of plants is highly variable. Young plants have more moisture content. As the plant maturity increases, the moisture content decreases. The dry matter of plants contains mainly carbohydrates. Carbohydrate serve s as a structural and reserve material in plants. In seeds carbohydrates occurs principally as starch while in stems and to a certain extent in leaves a considerable proportion of carbohydrate is present in the form of structural carbohydrates- (cellulose, hemicellulose and lignin. The lignin content of plant tissues increases with maturity of the plant. Protein is primarily present in active tissue such as the leaf. As the plant mature there is migration of the protein from the leaves to the seeds to serve as a reserve material for germination. Young tissues of plant, fruits, and seeds especially leguminous are rich in protein. Fat is present at highest level in the seeds followed by leaves and stem. Oil- bearing seeds have higher %age of protein and fat compared to cereals. The mineral content of plants is highly variable. It differs with species, plant parts and is also influenced by soil and other environmental factors. In plants there are various organic acids (citric, malic and fumaric) which are important for metabolism in the cells of plant. Vitamins both fat-soluble and water-soluble are also present in plants. Factors affecting chemical composition of plants 1. Plant factor - Chemical composition of different varieties of same species of forage vary because of different genetic material. 2. Agro-climatic condition - Atmospheric temperature and humidity affect the chemical composition of plants. 3. Cultivation practices – seed rate, seed treatment, time of sowing, method of sowing, manure and fertilizer, irrigation, weeds and disease control influence growth rate and the chemical composition of plants. 4. Stage of growth – The content of crude protein, soluble ash is higher just before flowering and goes down at bloom and seed formation stage whereas, crude fibre and dry matter content decreases as the plant matures. Ether extract goes down with the progressive maturity of the plant. 5. Processing and preservation practices – Different processing methods may change particle size, particle shape, nutrient content and composition of plant materials. % Chemical composition of some plants and their by-products Water Protein Fat Carbohydrate Ash Green plants Berseem 90.0 2.0 0.3 6.3 1.4 Cow pea 80.0 2.5 0.5 15.0 2.0 Maize 75.0 2.0 0.6 21.0 1.4 Pasture grass 84.0 3.6 1.0 10.0 2.4 Cereal grains Wheat 13.0 12.0 2.0 71.2 1.7 Seeds Groundnut 6.0 27.0 45.0 20.0 2.0 Plant by-products Paddy straw 10.0 3.5 1.5 70.5 14.5 Wheat straw 10.0 3.5 1.5 76.5 8.5 Rice bran 10.0 10.0 15.0 55.0 10.0 Wheat bran 10.0 10.0 3.0 70.0 7.0 Difference between plants and animals in their composition No Parameters Animal Plant 1 Major constituent Wate Wate 2 % dry carbohydrate 1r 75 r 3 Reserve energy as Fat Carbohydrate (Starch) 4 Structural component Protein and Carbohydrate (Cellulose, 5 As source of protein mineralGood Poor (except oil seeds) hemicelluose) 6 Mineral content Constant to Variable 7 Composition speciesLess Wide variability LESSON 2: NUTRITION TERMS AND THEIR DEFINITIONS A glossary of terms frequently used in discussing matters related to feed and nutrition is presented in this chapter. Additives: An ingredient or substance added to a basic feed mix, usually in small quantities, for the purpose of fortifying it with certain nutrients, stimulants and/or medicines. Ad Libitum: Free-choice access to feed. Agglomerated feed: A mixture of feeds in compacted or extruded form. Air dry (approximately 90% dry matter): This refers to feed that is dried by means of natural air movement, usually in the open. It may be either an actual or assumed dry matter content; the latter is approximately 90 %. More feeds are fed in the air dry state. Amino acids: Nitrogen-containing compounds that are the “building blocks” or units from which more complex proteins are formed. They contain both an amino (NH2) group and a carboxyl (COOH) group. Analogue: Anything that is analogous or similar to something else Animal Nutrition: Science of nourishment of animals. Animal Protein: Protein derived from meat-packing or rendering plants, surplus milk or milk products and marine sources. It includes proteins from meat, milk, poultry, eggs, fish and their products. Animal Protein Factor (APF): The term formerly used to refer to an undefined growth factor essential for poultry and swine and present in protein feeds or animal origin. It is now known to be as vitamin B12. Antimetabolite: A substance bearing a close structural resemblance to one required for normal physiological functioning, which exerts its effect by replacing or interfering with the utilisation of the essential metabolite. Antioxidant: A compound that prevents oxidative rancidity of polyunsaturated fats. Antivitamin: Any substance which inhibits the normal function of a vitamin. Apparent metabolisable energy (AME): It the gross energy of the feed consumed minus the gross energy contained in the faeces, urine and gaseous products of digestion. For poultry the gaseous products are usually negligible, so ME represents the gross energy of the feed minus the gross energy of the excreta. A correction for nitrogen retained in the body is usually applied to yield a nitrogen-corrected ME (MEn) value.. Appetite: This is immediate desire to eat when feed is present. Loss of appetite in an animal is usually caused by illness or stress. As-Fed: This refers to food as normally fed to animals. It may range from 0 to 100 % dry matter. Ash: The mineral matter of a feed. The residues that remain after complete incineration of the organic matter. Assay: Determination of (1) the purity or potency or a substance or (2) the amount of any particular constituent of a mixture. Available nutrient: A nutrient which can be digested, absorbed and/or used in the body. Average Daily gain (ADG): The average daily live weight increase of an animal. Balanced Ration: provides an animal the proper amount and proportion of all the required nutrients. Basal Diet: A diet common to all groups of experimental animals to which the experimental substances(s) is added. Basal Metabolic Rate (BMR): The heat produced by an animal during complete rest (but not sleeping) following fasting when using just enough energy to maintain vital cellular activity, respiration and circulation the measured value of which is called the basal metabolic rate (BMR). Basal conditions include thermo-neutral environment, resting post-absorptive state (digestive processes are quiescent), consciousness, quiescence and sexual repose. It is determined in man 14 to 18 hours after eating when at absolute rest. It is measured by means of a calorimeter and is expressed in calories per square meter of body surface. Biological value of a protein: The %age of the protein of a feed or feed mixture this is usable as a protein by the animal. Thus, the biological value of a protein is a reflection of the kinds of amounts of amino acid available to the animal after digestion. A protein which has a high biological value is said to be of good quality. Blended: Combined or mixed so as to render the constituent parts indistinguishable from one another such as when two or more feed ingredients are mixed. Bomb Calorimeter: An instrument used to measure the gross energy content of any material, in which the feed (or other substance) tested is placed and burned in the presence of oxygen. Brix: A term commonly used to indicate the sugar (sucrose) content of molasses. It is expressed in degrees and was originally used to indicate the %age by weight of sugar in sucrose solutions, with each degree Brix being equal to 1 % sucrose. By-product feeds: The innumerable roughage and concentrates obtained as secondary products from plant and animal processing and from industrial manufacturing. Cake (press cake): The mass resulting from the pressing of seeds, meat or fish in order to remove oils, fats or other liquids. Carrier: An edible material to which ingredients are added to facilitate their uniform incorporation into feeds. The active particles are absorbed, impregnated or coated into or onto the edible material in such a way as to carry the active ingredient physically. Cereals: A plant in the grass family (Graminacea), the seeds of which are used for human and animal food; e.g. Maize, Wheat. Chaff: Glumes, husks or other seeds covering, together with other plant parts, separated from seed in threshing or processing. Chelate: The word chelate is derived from the Greek word meaning “claw”. It refers to a cyclic compound which is formed between an organic molecule and a metabolic ion, the latter being held within the organic molecule as if by a claw. Examples of naturally occurring chelates are the chlorophylls, cytochromes, hemoglobin and vitamin B12. Coefficient of digestibility: The %age value of a food nutrient that is absorbed. For example, if a food contains 10 grams of nitrogen and it is found that 9.5 grams are absorbed, the digestibility is 95 %. Coenzyme: A substance, usually containing a vitamin, which works with an enzyme (protein mainly) to perform a certain function. Collagen: A white papery transparent type of connective tissue which is of protein composition. It forms gelatin when heated with water. Commercial feeds: Feeds mixed by manufacturers who specialize in the feed business. Concentrate: A broad classification of feedstuffs which are high in energy and low in crude fibre (under 18%). For convenience concentrates are classified as carbonaceous feeds and nitrogenous feeds. Cracked: Particle size reduced by combined breaking and crushing action Crude fat: Material that is extracted from moisture-free feeds by ether. It consists largely of fats and oils with small amounts of waxes, resins and colouring matter. In calculating the energy value of a feed, the fat is considered to have 2.25 times as much energy as either nitrogen-free extract or protein. Crumbles: Pelleted feed reduced to granular form. Decortications: Removal of the bark, hull, husk or shell from a plant, seed or root. Removal of portions of the cortical substance of a structure or organ, as in the brain, kidney and lung. Defluorinated: Processed in such manner that the fluorine content is reduced to a level which is nontoxic under normal use. Dehulled: Grains or other seeds with the outer covering removed. Dehydrate: To remove most or all moisture from a substance for the purpose of preservation, primarily through artificial drying. Desiccate: To dry completely. Depraved appetite (pica): A craving for and eating of unnatural substances, such as dirt, hair, dung, wood, etc. Diet: Feed ingredient or mixed or ingredient, including water, which is consumed by animals. Digestible nutrient: The part of each feed nutrient that is digested or absorbed by the animal. Digestible Protein: The protein of the ingested food protein which is absorbed. Digestion coefficient (coefficient of digestibility): the difference between the nutrients consumed and the nutrients excreted expressed as a %age. Dry matter: That partof a feed which is not water. It is computed by determining the %age of water and subtracting the water content from 100 %. Dry matter basis: A method of expressing the level of nutrient contained in a feed on the basis that the material contains no moisture. Dry Rolling: Refer to processing grains without added steam or other moisture. Efficiency of feed conversion: This is expressed as units of feed per unit of product meal, milk or eggs. Element: One of the many 105 known chemical substances that cannot be divided into simpler substance by chemical means. Emaciated: An excessively thin condition of the body: Energy: Vigor power in action.The capacity to perform work. Energy Feeds: Feeds that are high energy and low in fibre (under 18%), and that generally contain less than 20 % protein. Essential Amino acid: Those amino acids which cannot be made in the body form the other substances or which cannot be made in sufficient quantities for the body’s needs. Essential Fatty acid: A fatty acids that cannot be synthesised in the body or that cannot be made in sufficient quantities for the body’s needs. Ether Extract (EE): Fatty substances of feeds or foods that are soluble in ether. Evaporated: Reduced to a denser form; concentrated as by evaporation or distillation. Expanded: As applied to feed, it refers to an increase in volume as the result of a sudden reduction in the surrounding pressure. Expeller process: A process of the mechanical extraction of oil from seeds, involving the use of screw press. Extracted: Having removed fat or oil from materials by heat and mechanical pressure. Similar terms: expeller extracted, hydraulic extracted, old process. Extrinsic Factor: A dietary substance, which was formerly thought to interact with the intrinsic factor of the gastric secretion to produce the anitianemic factor, now known to be vitamin B12. Extruded: A type of feed preparation in which the feed is forced through a die under pressure. Fat: The term fat is frequently used in general sense to include both fats and oils or a mixture of the two. Both fats and oils have the same general structure and chemical properties, but they have different physical characteristics. The melting points of most fats are such that they are solid at ordinary room temperature, while oils have lower melting points and are liquids at these temperatures. Fat Soluble: Fat soluble in fats and fat solvents but generally not soluble in water. Fattening: The deposition of energy in the form of fat within the body tissues. Feed (or feedstuff): Any naturally occurring ingredient or material, fed to animals for the purpose sustaining them. Feed activities and implements: Non-nutritive products that improve the rate and/or efficient of gain of animals, % certain diseases, or pressure feeds, Feed efficiency: The ratio expressing the number of units of feed required for one unit of production (meat, milk, eggs) by animals. Feed Grade: Feedstuffs suitable for animals, but not for human consumption. Feed grain: Any of several grains mostly commonly used for livestock or poultry feed, such as corn, sorghum, oats and barley. Feedstuff: Any product, of natural or artificial origin, that has nutritional value in the diet when properly prepared. Fermented: Acted upon by yeasts, moulds or bacteria in a controlled aerobic or anaerobic process in the manufacture of such products as alcohols, acids, vitamins or the B complex group or antibiotics. Fibre content of a feed: The amount of hard-to-digest carbohydrates. Most fibre is made up of cellulose, hemicellulose and lignin. Fibrous: High in cellulose and/or lignin content. Finishing Animals: The laying on fat prior to slaughter Flakes: An ingredient rolled or cut into flat pieces with or without prior steam conditioning. Flavouring agent: Feed additives that are supposed to increase palatability and feed intake. Flora: The plant life present. In nutrition it generally refers to the bacteria present in the digestive tract. Formula feed: A feed consisting of two or more ingredients mixed in specified proportions. Fortify: Nutritionally to add one or more feeds or feedstuffs. Free-choice: Free to eat two or more feeds at will. Gluten: The though, viscid, nitrogenous substance remaining when the flour of wheat or other grain is washed to remove the starch. Grits: Coarsely ground grain from which the bran and germ have been removed, usually screened to uniformed particle size. Groats: Grain from which the hulls have been removed. Gross Energy (GE): is the energy released as heat when a substance is completely oxidised to carbon dioxide and water. Gross energy is also referred to as the heat of combustion. It is generally measured using 25 to 30 atmospheres of oxygen in a bomb calorimeter. Ground: Reduced in particle size by impact, sharing or attrition. Heat of fermentation (HF): The heat produced in the digestive tract as result of microbial action. Heat-processed: Subject to a method of preparation of involving the use of elevated temperature, with or without pressure. Hemicellulose: A carbohydrate classified in the crude fibre fraction of feedstuffs that is similar to cellulose, expect that it contains pentoses 95-carbon sugars) and uronic acid in addition to hexose. Hulls: Outer covering of grain or other seed, especially when dry. Hydraulic process: A process for the mechanical extraction of oil from seeds, involving the use of a hydraulic press. Sometimes referred to as “old process”. Hydrogenation: The chemical and addition of hydrogen to any unsaturated compound. Hydrolysis: The splitting of a substance in to a smaller units by chemically adding water to the material. Hypervitaminosis: An abnormal condition resulting from the intake of an excess of one or more vitamins. Hypocalcemia: Below normal concentration of ionic calcium in blood resulting in convulsion as in tetany or parturient paresis (milk fever). Hypomagnesemia: An abnormally low level of magnesium in the blood. Implant: A substance that is implanted into the body from the purpose of growth promotion or controlling some physical function. In Vitro: Occurring in an artificial environment, as in a test tube. In Vivo: occurring in the living body. Inert: Relatively inactive. Ingest: To eat or take in through the mouth. Ingesta: Food or drink taken into the stomach. Ingestion: The taking in of food and drink. Ingredient: A constituent feed material. IU(International Unit): A standard unit of potency of a biological agent eg,. Vitamin, hormone, antibiotic (antitoxin) and is defined by the International Conference for Unification of Formulae. Potency is based on bioassay that produces a particular effect agreed on internationally. Joule: An international unit (4.184 j = 1 calorie) for expressing mechanical ,chemical or electical energy as wells as the concept of heat. Keratin: A sulfur-containing protein which is the primary component of epiderms hair, wool, hoof, horn and the organic matrix of the teeth. Kernel: The whole grain of cereal. The meat of nuts and drupes (single-stoned fruits). Kjeldahl: A method of determining the amount of nitrogen in an organic compound. The quality of nitrogen measured is then multiplied by 6.25 to calculate the protein content of the feed or compound analysed. The method was developed by the Danish Chemist, J.G.C., Kjeldahl in 1983. Labile: Unstable. Easily destroyed. Lignification: The process of impregnating cell walls of a plant with lignin. Lignin: A practically indigestible compound which along with cellulose, is a major component of the cell wall of certain plant materials, such as wood, hulls, straws and overripe hays. Limiting Amino Acid: The essential amino acid of a protein which shows the greatest %age deficit in comparison with amino acids contained in the same quantity of another protein selected as a standard. Macro or major Mineral: The Major mineral calcium, phosphorus, sodium, chlorine, potassium, magnesium and sulfur. Malnutrition: Any disorder of nutrition, commonly used to indicate a state of inadequate nutrition. Meat Anologs: Food material usually prepared from vegetable protein to resemble specific meats in texture, colour and flavour. Meats: Animal tissue used as food. The edible parts of huts or fruits. Mechanically Extracted: A method of extracting the fat content from oil seeds by the application of heat and mechanical pressure. The hydraulic and expeller process are example for mechanical extraction. Medicated feed: Any feed which contains drug ingredients intended or represented for the cure, mitigation, treatment or prevention of diseases of animals (other than man). Metabolism: Refers to all the changes that take place in the nutrients after they absorbed from the digestive tract, including (1) the building-up process in which the absorbed nutrients are used in the formation or repair of body tissue and (2) the breaking down process in which nutrients are oxidised for the production of heat and work. Metabolizable Energy (ME): It is the gross energy of the feed consumed minus the gross energy contained in the faeces, urine and gaseous products of digestion. For poultry the gaseous products are negligible. Metabolite: Any substance produced by metabolism or by a metabolic process. Mill by-product: A secondary product obtained in addition to the principal product in milling practice. Minerals (ash): The inorganic elements of animals and plants determined by burning off the organic matter and weighing the residue. Mineral Supplement: A rich source of one or more of the inorganic elements needed to perform certain essential body functions. Mixing: to combine by agitation two or more materials to a specific degree of dispersion. Moisture: A term used to indicate the water contained in feed. Moisture-free (M-F, oven-dry, 100% dry matter): This refers to any substance that has been dried in an oven at 221oF (105oC) until all the moisture has been removed. Mycotoxins: Toxic metabolites produced by molds during growth. Sometimes present in feed materials. National Research Council (NRC): A division of the National Academy of Science of USA established in 1916 to promote the effective utilisation of scientific and technical resources. Periodically, this private, non-profit organisation of scientists publishes bulletins giving nutrient requirements and allowance of domestic animals. Net Energy (NE): is metabolisable energy minus the energy loss as the heat increment. NE may include the energy used for maintenance only (NEn) or for maintenance and production (NEm+p). Because of NE is used at different levels of efficiency for maintenance or various productive functions, there is no absolute NE value for each feedstuff. For this reason, productive energy, once a popular measure of the energy available of NE is seldom used. Nitrogen: A chemical essential to life. Animals get it from protein feeds; plants get it from the soil; and some bacteria get it directly from the air. Nitrogen Balance: The nitrogen in the feed intake minus the nitrogen in the faeces, minus the nitrogen in the urine. Nitrogen-Free Extract (NFE): It consists principally of sugars, starches, pentoses and non-nitrogenous organic acid. The %age is determined by subtracting the sum of the %age of moisture, crude protein, crude fat, crude fiber and ash from 100. Nonprotein Nitrogen (NPN): Nitrogen which comes from other than a protein source but may be used by a ruminant in the building of protein. NPN sources include compounds like urea and anhydrous ammonia, which are used in feed formulation for ruminants only. Noxious: Harmful, not wholesome. Nutrient allowances: Nutrient recommendation that allow for variations in feed composition, possible losses during storage and processing, day-to-day and period-to-period differences in needs of animals age and size of animal; stage of gestation and lactation; the kind and degree of activity, the amount of stress, the system of management, the health, condition, and temperature of the animal and the kind , quality and amount of feed-all of which exert a powerful influence in determining nutritive needs. Nutrient requirements: This refers to meeting the animal’s minimum needs, without margins of safety for maintenance, growth, fitting, reproduction, lactation, and work. To meet these nutritive requirements the different classes of animals must receive sufficient feed to furnish the necessary quantity of energy (carbohydrates and fats), protein, mineral and vitamins. Nutrient to calorie ratio: The energy needs of animals and their requirements of the several nutrients are quantitatively corrected. For those nutrients that are needed to metabolise energy, it is logical to consider that the amount of energy metabolised “determines” their requirements. Hence, it is logical to express nutrients in weight per unit of energy needed. For example, it is suggested that the protein to calorie ratio should be expressed as grams of protein per 100 kcal metabolisable energy (g peotein/100 kcal ME). If the ME is corrected for nitrogen retained or lost from the body), then the abbreviation should be g protein/100 kcal MEn. This same dimension may easily to extend to other nutrients, such as g calcium/100 kcal or mg riboflavin/100 kcal. Etc. Nutrients: The chemical substance found in feed materials that can be used and are necessary, for the maintenance, production and health of animals. The chief classes of nutrients are carbohydrates, fats proteins, minerals, vitamins and water. Nutriment: anything that promote growth or development Nutrition: The science encompassing the sum total process that have as a terminal objective of the provision of nutrients to the component cells of an animal. Obese: Overweight due to surplus of body fat. Off feed: Not eating with a normal healthy appetite. Oil: Although fats and oils have the same general structure and chemical properties, they have different physical characteristic. The melting points of oils are such that they are liquid at ordinary room temperature. Orts: Leftover feed which an animal refuses to eat. Palatability: The result of the following factors sensed by the animal in locating and consuming feed, appearance, odor, taste, texture, temperature and in some cases, auditory properties of the feed (like the sound of pigs eating corn). These factors are affected by the physical and chemical nature of feed. Palatable Feeds: Feeds that are well liked and eaten Pantothenic acid: One of the B Vitamins. It is a constituent of coenzyme A, which plays an essential role in fat and cholesterol synthesis. Parts per billion (PPB): It equals micrograms per kilo gram or micro litre per litre. Parts per million (PPM): It equals milligrams per kilo grams or micro litre per litre. Pearled: De-hulled grains reduced into smaller smooth particles by machanic brushing or abrasion. Pectin: Any of the group or colourless, amorphous, methylated, pectic substance occurring in plant tissue or obtained be restricted treatment of protopectin that are obtained from fruits or succulent vegetables, that yield viscous solutions with water and when combined with acid and sugar, yield a gel. Peelings: Outer layers of covering which have been removed by stripping or tearing. Pelletes: Ground feed compacted by steaming and forcing the material through die opening. Pellet binders: Products that enhance the firmness of pelletes. Phase Feeding: Refers to change in animal’s diet (1) to adjust for age and stage of production, (2) to adjust for season of the year and for temperature and climate changes, (3) to account for differences in body weight and nutrient requirements of different strains of animals or (4) to adjust on or more nutrient as other nutrients are changed for economic or availability reasons. Plant Proteins: This group includes the common oilseed by-products – soyabean meal, cottonseed meal, linseed meal, peanut meal, safflower meal, sunflower meal, rapeseed meal, and coconut (or copra) meal. They vary in protein content and nutrient value, depending on the seed from which they are produced, the amount of hull and/or seed coat included and the method of oil extraction used. Polyunsaturated fatty acids: Fatty acids having more than one double bond. Linoleic and linolenic acids, which contain 2 and 3 bonds respectively are essential in the diet of man. Precursor: A compound that can be used by the body to from another compound for example, carotene is a precursor of vitamin A. Preservartives: A number of materials are available to incorporate into feed and their products, with claims made that they will improve the preservation of nutrients, nutritive value and/or palatability of the feed. Pressed: Compacted or moulded by pressure; having fat, oil or juice extracted under pressure. Pressure cooker: An airtight container for the cooking of feed at high temperature under steam pressure. Protein: From the Greek meaning “of first rank importance”. Complex organic compounds made up chiefly of amino acids present in characteristic proportions for each specific protein. At least 24 amino acids have been identified and may occur in combinations to form an almost limitless number of proteins. Protein always contains carbon, hydrogen, oxygen and nitrogen and in addition it usually contains sulfur and frequently phosphorus. Crude protein is determined by finding the nitrogen content and multiplying the result by 6.25. The nitrogen content of proteins averages about 16 % (100/16=6.25). Proteins are essential in all plant and animal life as components of the active protoplasm of each living cell. Protein equivalent: A term indicating the total nitrogenous contribution of substance in comparison with the nitrogen content of protein (usually plant protein). For example, the non- protein nitrogen (NPN) compound urea contains approximately 45 % nitrogen and has a protein equivalent of 281 % (6.25  45%). Protein-sparing: An effect in which less proteins is used by the animal to meet the animal’s glucose needs in times of glucose shortage. Propionic acid is protein sparing in that it can be converted to glucose. Acetic and butyric acid cannot be converted to glucose. Likewise, fat cannot be converted. The glycogenic amino acids may be converted to glucose. Protein Supplements: Products that contain more than 20 % protein or protein equivalent. Proximate Analysis: A chemical scheme for evaluating feedstuffs, in which a feed stuff is partitioned into the six fractions: (1) moisture (water) or dry matter (DM); (2) total (crude) protein (CP or TDN  6.25); (3) ether extract (EE) or fat; (4) ash (mineral salts); (5) crude fiber (CF) – the incompletely digested carbohydrates and (6) nitrogen-free extract (NFE) – the more readily digested carbohydrates (calculated rather than measured chemically). Purified Diet: A mixture of the known essential dietary nutrients in a pure form and are fed to experimental (test) animals in nutrition studies. Quality: A term used to denote the desirability and/or acceptance of an animal or feed product. Quality of protein: A term used to describe the amino acid balance or protein. A protein is said to be of good quality when it contains all the essential amino acids in proper proportions and amounts needed by a specific animal and it is said to be poor quality when it is deficient in either content or balance of essential amino acids. Ration(s): The amount of feed supplied to an animal for a definite period, usually for a 24 hour period. However by practical usage the word ration implies the feed fed to an animal without limitation to the time in which it is consumed. Saturated fat: A completely hydrogenated fat-each carbon atom is associated with the maximum number of hydrogens; there are no double bonds. Selenium: An element that functions with glutathione peroxidise, an enzyme which enables the tri-peptide glutathione to perform its role as a biological antioxidant in the body. This explains why deficiencies of selenium and vitamin E result in similar signs- Sodium Bentonite (clay): Used as a pellet binder. Also shows promise for improving the nitrogen utilisation or ruminants. Solvent-extracted: fat or oil removed from materials (such as oilseeds) by organic solvents. Sorghum: A cereal grain used mainly for as feed grain. Specific Dynamic Action (SDA): The increased production of heat by the body as a result of stimulus to metabolic activity caused by ingesting food. Spray-dehydrated: Material which has been dried by spraying onto the surface of heated drum. It is recovered by scraping it from the drum. Stablised: Made more resistant to chemical change by the addition of a particular substance. Steamed: Treatment of ingredients with steam to alter either its physical and/or chemical properties. Sun-cured: Material dried by exposure in open air to direct rays of the sun. Supplement: A feed or feed mixtures used to improve the nutrition value of basal feeds (eg. Protein supplement-soyabean meal). Supplements are usually rich in protein, minerals, vitamins, antibiotic or a combination of part or all of these and they are usually combined with basal feeds to produce a complete feed. Toxaemia: A condition produced by the presence of poisons toxins in the blood. Trace Elements: A chemical element used in minute amounts by organism and held essential to their physiology. The essential trace elements are cobalt, copper, iodine, iron, manganese, selenium and zinc. Trace mineral: A mineral nutrient required by animals in micro amounts only (measurable in milligrams per kilogram or smaller units). True metabolisable energy (TME) for poultry is the gross energy of the deed consumed minus for gross energy of the excreta of feed origin corrected for nitrogen retention, may be applied to give a TME value. Most MEn values in the literature have been determined by assay in which the test material is substituted for part of the test diet or for some ingredient of known ME value. When birds in these assay are allowed to consume feed on an ad libitum basis, the MEn value obtained approximate TMEn values for most feedstuffs. True protein: A nitrogenous compound which will hydrolyze completely to amino acids. Unsaturated fat: A fat having one or more double bonds; nor completely hydrogenated. Unsaturated Fatty acid: Any one of several fatty acids containing one or more double such as oleic, linoleic, linolenic and arachidonic acids. Vaccum-dehydated: Removal of moisture after removal of surrounding air while in an airtight enclosure. Vitamins: Complex organic compounds that function as parts of enzyme systems essential for the transformation of energy and the regulation of metabolism of the body, and required in minute amounts by one or more animal species for normal growth, production, reproduction, and/or health. All vitamins must be present in the ration for normal functioning except for B vitamin in the ruminants (cattle and sheep) and vitamin C. LESSION 3: NUTRITIONAL ASPECTS OF CARBOHYDRATES Definition Carbohydrates are polyhydroxy aldehydes or ketones, their polymers or their product of oxidation and reduction or products of substitutional esters. They are organic substances containing carbon, hydrogen and oxygen. They are widely distributed in plants, and synthesised by photosynthesis. Carbohydrates form the largest part of animals food supply. Functions of carbohydrate a) Source of energy for muscular activity, heart muscles etc. b) Carbohydrates are needed for oxidation of fat c) Synthesis of ribose from glucose. (Ribose is incorporated in RNA and nucleotides) d) In liver carbohydrates function in detoxification and they regulate protein metabolism e) Protein sparing action of carbohydrates - if inadequate protein is used as source of energy, tissue protein break down can be avoided by providing adequate carbohydrates f) Production of Volatile Fatty Acids in the rumen g) For synthesis of fatty acids h) For synthesis of non-essential amino acids eg.oxaloacetate → aspartic acid i) For glycolipids synthesis j) For ascorbic acid synthesis Classification of Carbohydrate 1. Monosacharides They contain only one molecule of sugar and they cannot be broken down by hydrolysis. Depending on the number of carbon atoms they are classified as trioses (3 carbon), tetroses (4 carbon), Pentoses (5 carbon) and Hexoses (6 carbon). a. Triose – eg. Glyceraldehyde and dihydroxy acetone. b. Tetrosees – eg. Erythrose. c. Pentoses– Ribose, xylose and arabinose, ribulose and xylulose. d. Hexoses – Glucose, Fructose, Galactose Glucose also called as dextrose occurs as free form in many fruits (2-5%), honey (30-40%), blood, lymph, CSF. It is sole component of many polysaccharides like starch, celluose, dextrins and glycogen. It is the principal end product of digestion of higher carbohydrates. It is a reducing sugar and readily undergoes acid fermentation. Fructose (levulose) occurs along with glucose in a free state in fruits (2-5 %), honey (30-40 %) and green grasses. It is the only important keto - hexose. It is sweeter than glucose and readily undergoes fermentation. It is also called as fruit sugar. Galactose - It does not occur free in nature. It occurs in milk sugar (lactose) in combination with glucose. Certain compounds of galactose, galactosides occur in the brain and nervous tissue. It is also a component of pigments, galactolipids, gums and mucilages. 2. Oligosacharide: yields 2-10 monosacharides on hydrolysis. i. Disaccharide – yields 2 monosacharides on hydrolysis. a) Sucrose (Cane sugar 10-12%, beet sugar 12-18%) sucrase Sucrose glucose + fructose b) Maltose (Malt sugar) found in cereal grains (Barley, Jowar, Ragi etc.) maltase Maltose glucose + glucose c) Lactose (Milk sugar) occurs in milk of all animals. lactase Lactose glucose + galactose ii. Tri sacharides: yields 3 monosacharides on hydrolysis. Raffinose: On hydrolysis yields glucose, galalactose and fructose. It cannot be digested enzymatically in the human gut. In the colon, bacterial enzymes ferment it. It is present in fair amount in beet root and cottonseed meal. iii.Tetrasaccharides: Yields 4 monosacharides on hydrolysis. Stachyose: present in plants. 3. Polysaccharides: classified as homoglycans and heteroglycans. 3.a. Homoglycans - e.g. pentosan and hexosan, fructans galactan and mannan i. Pentosane.g. araban, xylan ii. Hexosan e.g. starch, glycogen, dextrin, and cellulose. Starch: It is a reserve polysaccharide present in plants. This polysaccharide consists of two component amylose (17-25%) and amylopectin (75-83%). Starch is made up of glucose units linked together by  1-4 linkages in the case of amylopectin there is also  1-6 linkages Partial hydrolysis Starch dextin + dextromaltose The complete hydrolysis of starch gives maltose. Starch is present in the form of starch granules in the plant. the size and shape of which is variable in different plants. On treatment with moist heat the starch granules swell and burst open liberating the starch and this process is called gelatinisation. Starch gives a characteristic blue colour with iodine. Glycogen: It is the reserve carbohydrate present in human and animal body mainly in muscles (0.5-1 %) and liver (3.7 %). It is similar to starch formed by the condensation of 5000 – 10,000 glucose molecules. It is sometimes referred to as animal starch. It gives a brown red colour with iodine. Dextrins: It is an intermediate compound formed on partial hydrolysis of starch or glycogen. Cellulose: It is a polysaccharide that contains linear chain of glucose units attached by ,1- 4 linkages. Cellulose occurs nearly in pure form in cotton. It occurs in plants in combination with lignin. Cellulose in plants are organised as fibrils and many fibrils aggregate and are held by intramolecular hydrogen bonding. iii. Fructans Inulin: In certain plants inulin replaces starch as reserve carbohydrate. Inulin is a polysaccharide, which yields fructose on hydrolysis. Fructose units are linked together by 2-1 linkages Levans:is a polysaccharide, which yields fructose on hydrolysis. Fructose units are linked together by 2-6 linkages iv. Galactans:It is a polysaccharide that contains galactose units and is present in many leguminous seeds. Mannans:It is a polysaccharide that contains mannose units and is present in palm seeds. 3.b. Heteroglycans – hemicellulose, gums, pectins, mucilage etc. i. Hemicellulose: This includes a group of substances including araban, xylan, certain hexosans and poly uronoides. They are distributed widely in forages. Pectins: They are a group of substances, which occur in cell walls of plants. Their fundamental structural unit is galacturonic acid. Digestion and Absorption of Carbohydrate in Monogastric Animals salivary/pancreatic amylase Starch Maltose sucrase Absorption by passive transport Sucrose fructose + glucose lactase Lactose glucose + galactose maltase Absorption by Active transport Maltose glucose + glucose Sucrase, lactase and maltase are secreted from small intestine. Digestion and Absorption of Carbohydrate in Ruminants Upon ingestion, feed entering rumen is regurgitated back (rumination) and broken down into small particles which increases surface area of feed for the action of microbial enzymes. The breakdown of carbohydrates in the rumen may be divided into two stages. First, storage complex carbohydrates are broken down to simple sugars.  1,3 glucosidase Cellulose –––––––––––––→ Cellobiose  1,4 glucosidase Starch / dextrin –––––––––––––→ Hexoses Pectic lytase and hemicellulase Pectin, hemicellulose ––––––––––––––––––––→ Uronic acid and pentoses 2,1/2,6 linkage attacking enzymes Fructans ––––––––––––––––––→ Fructose The simple sugar produced in the first stage of carbohydrate digestion (glucose) is rarely detected in rumen liquor.It is taken up and metabolised intracellular by rumen microbes. The major end products of rumen carbohydrate digestion are short chain volatile fatty acids (VFA) namely acetic, propionic, butyric acid and CO2 and methane. The VFA production in rumen varies widely according to diet. Normally, mature forages gives high proportion of acetic acid (70%). Less mature forages gives low proportion of acetic acid and high proportion of propionic acid. The addition of concentrates increases the production of propionic acid at the expense of acetic acid. With all concentrate diet, proportion of propionic acid exceeds acetic acid. The acid produced is absorbed directly from the rumen, reticulum and omasum. Some products of carbohydrate digestion are used up by rumen microorganisms to form their complex polysaccharide. Gas production in rumen is around 30 l/hour and it depends on the type of feed. Rumen gas composition: CO2 – 40%, CH4 – 30-40%, H – 5% and traces of O2 and N2 Gases produced in the rumen are lost by a process of eructation. If the gases accumulate, it leads to a condition known as bloat. If the gases produced in the rumen are entrapped in the form of foam due to the presence of some antinutritional factor like saponin then the bloat is called as frothy bloat. When the animals are fed on high concentrate diet, it results in a condition known as feedlot bloat. Methane Production: Methane is produced in rumen by methanogenic bacteria (methanogenesis). 4.5 gram of methane is produced for every 100 gram of carbohydrate digested. In ruminant animal, nearly 7 % of total feed energy is lost as methane. Factors Affecting Carbohydrate Digestion in the Rumen Degree of lignification – as lignin increases cellulose digestion decreases. Rumination Ruminal contractions Rumen microorganisms Retention time in the rumen Ration composition LESSION 6: NUTRITIONAL ASPECTS OF PROTEINS Proteins are complex organic compounds of high molecular weight. They contain carbon, hydrogen, and oxygen and nitrogen. The presence of nitrogen distinguishes them from carbohydrate and fat. In addition, some proteins have sulphur and phosphrous. Elementary composition of protein Carbon Hydrogen Nitrogen Sulphur Phosphorus 51 − 55 % 6.5 − 7.3 % 15.5 − 18 % 0.5 − 2 % 0 − 1.5 % Proteins are polymers of amino acid, which vary in relative amounts and kind from protein to protein. They vary in size, shape, suitability and biological function. There are around 200 naturally occurring amino acids, among them only 20 are commonly found in most of the proteins and up to 10 amino acids are not adequate to meet the metabolic needs. Amino acids There are basically 20 standard amino acids having different structures in their side chains(R groups). The common amino acids are known as α-amino acids because they have a primary amino group (-NH2) and a carboxylic acid group (-COOH) as substitutes of the α carbon atoms. Proline is an exception because it has a secondary amino group (-NH-). NH2 R Cα H COOH General structure of α- amino acid General properties of amino acids Theamino and carboxylic acid groups of amino acids readily ionize. At a pH(~7.4), the amino groups are protonated and the carboxyl acid groups are in their conjugate base(carboxylate) form, this shows that an amino acid that can act as an Acid and also a base. Amino acids can bear charged groups of opposite polarity, hence they are know as zwitterions or dipolar ions. The ionic property of the side chains influences the physical and chemical property of free amino acids and amino acids in proteins. 1) Some amino acids could be synthesized by the body. 2) Some amino acids could be synthesized but could not meet the demands. 3) Some could not be synthesized at all. The 2 and 3rd are classified under essential amino acids and is defined as “one, which cannot nd be synthesized in the bo dy at a rate, required for normal growth”. They are called as indispensable amino acids. 10 amino acids have found to be essential. Different animals have different capacity of synthesising amino acid types. So the list of essential amino acids is different from species to species Body amino acids Dietary essential amino acid. Dietary non-essential amino acid Classification of amino acids A) Aliphatic, aromatic and Heterocyclic amino acids B) Based on the number of amino and carboxyl group present. They are (a) Mono-amino, mono-carboxylic acids –Glyceine,alanine,valine,Iucerne, isolucine (b) Mono-amino, dicarboxylic acids – Aspartic, Glutomic (c) Diamino, monocarboxylic acids – Arginine, Iysine ` C) From nutritional point of view, they are classified as essential and non-essential amino acids. D) According to their catabolic fates as (1) Glucogenic (2) Kitogenic (3) Glucogenic (or) ketogenic. Non-essential amino acid/Dispensable can be synthesized from whatever precursor available eg. Amino nitrogen. The essentiality of the several amino acids is a reflection of the cell’s inability to synthesise the necessary carbon skeletons (α – Ketoacids) to which the amino nitrogen can be attached. Essential amino acid Arginine, Histidine, Isoleucine, leucine, lysine, Methionic, Phenylalanine, Threonine, Tryptophan and Valine Non-essential Alanine, Aspartic acid, Citrulline, Cystine, Glutamic acid, amino acid Glysine, Hydroxyl proline, Proline, Serine, Tyrosine. Function of amino acids 1) Synthesis of cell protoplasm 2) For the repair of wear and tear 3) Synthesis of Bile acid 4) Synthesis of Hormones, enzymes, milk proteins. 5) Synthesis of Melanin 6) Formation of Rhodopsin 7) Supply of energy 8) Precursor for many of the biological compounds. Availability of amino acid in non-ruminant and ruminants: Amino acid availability is critical in the nutrition of non-ruminant. Since, they do not have the ability to synthesise certain essential amino acids. The requirement of individual amino acid have to be calculated to avoid a deficiency or excess, which can severally affect the protein through total protein levels appear to be adequate. In Ruminants: The dietary protein is subjected to microbial attack in the rumen and microbial protein gets digested in small intestine. ❖ High quality protein: Those proteins whose amino acid molecules are more nearly approximate the needs of the animal. Eg.: animal protein. ❖ Low quality protein: Which do not meet the needs of the animal. Eg. Plant protein ❖ Dispensable Amino acids: They make up almost 40% of tissue protein and are of quantitatively important. Not all must be synthesized as the diet can provide many. If there is short supply, the cells with an adequate supply of amino nitrogen and a source of carbon and energy will make up the deficit. Eg:Glutamic (Ketoglutarate + NH4+) (amination) Glutamine (glutamic + NH4T) (amination) Glutamic acid is an important one which makes an effective sources of non-specific N2.Tyrosine and cystine are derived from the essential amino acids phenyl alanine and methionine respectively. As there are requirements for building up of tissue protein and a source of energy a metabolic requirement of amino acid is to be provided. Non-ruminant omnivores such as the pig, chicken and human require specific dietary amino acids (EAA) whereas non-ruminant herbivores such as horses and rabbits can utilize NPN for microbial protein synthesis in lower gut. Adult ruminants can entirely depend on NPN for microbial protein synthesis. Protein digestion and absorption in non-ruminants Being high molecular weight substances absorption is possible after being broken into low molecular weight compounds (into mucosal cells of small intestine) Digestive site Source of enzyme Stomach, Upper small intestine Mucosa of stomach and intestine, The pancreas Proteases are secreted as zymogens (inactive precursor) Zymogen Removal of small peptide which (by enzymatic process) active enzyme Blocks active center of enzyme in the precursor state The hydrogen ions concentration in the stomach permits autohydrolytic conversion of the pepsiogen to pepsin. The proteolytic enzymes, their production sites and specialty of action Splits peptide bonds PH of optimal Enzyme Site of production adjacent to activity Pepsin Mucosa of stomach Tryptophan 1.8-2.0 Phenylalanine Tyrosine Methionine Luecine Trypsin Pancreas Arginine lysine 8-9 Chymotrypsin Pancreas Phenylalanine 8-9 Tyrosine Methonine Elastase Pancreas Aliphatic 8-9 Amino acids Aromatic amino acids Carboxy peptidase A Pancreas Aromatic amino acid 7.2 Carboxy peptidase B Pancreas Arginine, lysine 8.0 Almino peptidase Mucosa of intestine Amino acid with free 7.4 NH2 group Endo enzymes - trypsin, chymotrypsin Cleave large peptides into smaller one by acting in middle of the large peptide chain. Exopeptidases- act on small peptides attack terminal peptide linkage to yield free amino acids. Aminopeptidases- peptide with free terminal – NH2 group Subsequent hydrolysis occurring in the adjacent bond liberation of terminal amino acid. Protein Absorption: Site - smaller intestine Amino acid absorption - Na dependant active transport Pyridoxine - enhance normal amino acid transport across cell membrances Amino acid transport system: 1. Neutral 2. Basic 3. Acid amino acids Members of each group compete among themselves but not with those of other groups for absorption only free amino acid portal blood liver The rate of the amino acid absorption depends on, i) Amino acid composition of the digest ii) Rapid amino acid absorption increased postprandial concentration of amino acid in portal circulation Intestinal epithelium - impermeable to protein Only new born mammals - absorb protein (immunoglobulin) in the colostrum LESSION 5: NUTRITIONAL ASPECTS OF FATS Lipids are organic compounds that are relatively insoluble in water but relatively soluble in organic solvents such as ether, chloroform and benzene and serve important functions in plant and animal tissues. Like carbohydrates the fats contain carbon, hydrogen, oxygen but the first two elements (C and H) are present more in fats. Carbon Hydrogen Oxygen Fat 77 12 11 Starch 44 06 50 Classification of lipids LIPIDS Glycerol based Non-glycerol based Simple Compound Waxes Fats, Oils Steroids Celebrosides Terpenes Glycolipids Phospholipids Glucolipids Galactolipids Lecithin Cephalin Sphingomyelin 1. Simple Lipids True fats - esters of fatty acids with glycerol. waxes - ester of fatty acids with alcohol other than glycerol. Compound Lipids - Esters of fatty acids with glycerol and contain additional elements like phosphorus and nitrogen. a) Phospho lipids – fats containing nitrogen and phosphorus: lecithin, cephalin and sphingomyelin. b) Glyco lipids: fats with molecule of carbohydrate, eg. cerebrosides. 3. Derived Lipids - Substances derived from simple lipids and compound lipids on hydrolysis. Sterols are lipids with complex phenanthrene ring structure.eg. cholesterol, ergosterol etc. Terpenes are compounds that usually have isoprene-type structure. FATS True fats are esters of fatty acids with glycerol (Trihydric alcohol). They are also known as triglycerides or tryacylglycerol because each one on glycerol is combined with three molecules of fatty acids. The carbon atoms or glycerol are identical by numbers 1, 2 and 3 by α, β and . (α) CH2-O-COR1 │ (β) CH-O-CO-R2 │ () CH2-0-CO-R3 Fatty acids are long chain organic acids, having 4 - 24 carbon atoms and a single carboxy1 group (COOH). The same (tripalmitic) or different fatty acids may be in all three positions (oleopalmitostearin). The chain length and degree of unsaturation of the fatty acids making up the triglyceride determine its physical and chemical properties. Triglycerides of saturated fatty acids containing at least ten carbon atoms are solid at room temperature, whereas those with less than ten carbon atoms are liquids.The acids found in fats have an even number of carbon atoms, the fatty acids most frequently occurring in fats are: C13H32O2 Palmitic acid C18H36O2 Stearic acid C18H37O2 Oleic acid Biological significance of fats 1. Fats are important source of stored energy in plants and animals and are characterized by their high energy value (1 gram fat=9.3 Kcal or 39.1 KJ) 2. Components of biological membrane 3. Carrier for fat soluble vitamins – A,D,E and K 4. Useful as electron carrier 5. Useful source of metabolic water 6. Deposits of fat underneath the skin exert insulating effect to the body thus protecting it from excessive heat or cold. The mesenteric fat acts as a padding to protect the internal organs. 7. Sources of essential fatty acids – linoleic, linolenic, and arachidonic acids. 8. Normal breakdown products of fatty acids such as acetic acid and bile acids form important building blocks of biologically active materials like cholesterol, sex hormones and steroids Rancidity Auto oxidation occurring in natural edible fats, which are rich in unsaturated fatty acids is called rancidification. The chemical changes which occur during rancidification are known as rancidity and this takes place in two stages, namely; 1. Hydrolytic rancidity 2. Oxidative rancidity Hydrolytic Rancidity It involves partial hydrolysis of the triglycerides to mono and diglycerides, while glycerol and free fatty acids are also liberated. The hydrolysis is hastened in the presence of moisture, warmth and lipases present in fats. Hydrolytic rancidity of butter (high in volatile fatty acids) produces disagreeable odour and taste due to the liberation of the butyric acid. Oxidative Rancidity The unsaturated fatty acids are oxidized at the carbon atom adjacent to the double bond to form hydroperoxides which may break down to give unsaturated aldehydes or ketones. Development of oxidative-oily, metallic taste is accelerated by the presence of heavy metals such as copper and irons and by exposure of the fat to ultra-violet light. Ketotic Rancidity Oxidation of standard fatty acids due to the presence of methyl kentones resulting the development of a sweet, heavy taste and smell is known as ketotic rancidity. Prevention of Rancidity Antioxidants prevent the oxidation of unsaturated fats until they themselves have been transformed into inert products. A number of compounds have the antioxidant property. They include vitamins C and E, phenols, gallic acids, quinines, propyl, octyl or dodecyl gallate, butylated hydroxyanisole or butylated hydroxyl toluene. i) Proper storage of the fats in airtight nonmetallic receptacles kept in cool place away from light, moisture. ii) Addition of antioxidants. Keries test is used to detect oxidative rancidity, wherein; the fat is treated with ether, phloroglucinol and hydrochloric acid. Positive test is indicated by the development of red colour due to the presence of epihydrine aldehyde, which is one of the oxidation products. Hydrogenation Triglycerides containing largely unsaturated fatty acids, which are liquid at room temperature can be converted into solid fats by hydrogenation of their double bonds. For example hydrogenation of oleic acid yields stearic acid. This process in widely employed for converting vegetable and fish oils into margarine and it’s catalysed by addition of finely divided nickel. The hardening results from the higher melting points of the saturated acids and improves the keeping quality of the fat, since removal of double bond eliminates the chief centres of reactivity in the material. Rumen microbes enzymatically hydrogenate dietary unsaturated fatty acids, helping to reconcile the apparent contradiction that whereas their dietary fats and highly unsaturated, ruminant body fats are high saturated. Fatty acid composition of fats The composition of fats of animal origin depends on the species of animal and in the different tissues and is also influenced to some extent by the diet. Fats of plants, fish and birds are highly unsaturated due to the presence of varying amounts of linoleic and linolenic acids in addition to the unsaturated oleic acid than those of mammals. Within individual animals subcutaneous fats contain a higher proportion of unsaturated fatty acids than the fat from the liver of same mammalian species. The physical nature of fat varies between animals, marine mammals in order to maintain a degree of malleability at the temperature of the tissue. The fats in the ruminant body are highly saturated due to considerable hydrogenation of unsaturated dietary fats occurring in the rumen. Ruminant lipids contain small amounts of odd- chain and branched-chain fatty acids, which are products of microbial metabolism. Ruminant milk fat contains a considerable %age (20%) of short chain fatty acids (2-8 carbon atoms). Hence ruminant milk fat is softer than the body fat. Essential Fatty acids Despite the fact that certain lipids are essential constituent of animal tissues, the knowledge that carbohydrate can be converted to fat and that some of the lipids constituents like phospholipids, cholesterol can be synthesized, led to the belief that lipids as such are not required in the diet. Later investigations showed that rats on a completely fat free diet developed a scaly condition of the skin and necrosis of the tail. Failure of growth occurred and even death resulted. Harmful effects on reproduction and lactation performance were also noted. Addition of small amount of linoleic acid was strikingly effective in preventing and curing the disease. Saturated acids were not effective. Later, arachidonic and Linolenic and Linoleic are commonly referred to as essential fatty acids. Though the body can synthesis unsaturated fatty acids, it is suggested that the body does not have enzyme system to synthesis unsaturated fatty acids with 2 or 3 double bonds. Though these acids are referred to as essential fatty acids (EFA) there is possible intra conversion between them. There is species variation as regards to the extent of intra conversion. In rat, either linoleic or arachidonic will serve as precursor for the other two. In chick linolenic is convertible to the other two. Like other polyunsaturated fatty acids, arachidonic acid i) forms part of the structural lipids of cell membranes ii) is a precursor for the biosynthesis of prostaglandins and thromboxanes, hormone-like substances, which regulate many different cell functions, particularly in reproductive organs of man and animals. Because of the presence of linoleic acid and its higher homologues in higher concentration in phosphoglycerides of the central and peripheral nervous system, they are throughout to have important role there. The formulae for these polyunsaturated fatty acids are, Linoleic acid - C18H32O2 Linolenic acid - C18H30O2 Arachidonic acid - C20H32O2 These acids contain the characteristic group –CH=CH-CH2-CH=CH-, which is two double bonds separated by a methylene group. Essential fatty acids are required by chicks, calves and goats. Only linoleic acid is an essential nutrient for chicken. A deficiency of essential fatty acids is not common in practical diets. Excessive amounts are not desirable because of the susceptibility of polyunsaturated acids to oxidation. Non-esterified fatty acids (NEFA) NEFA arise in the plasma from lipolysis of triglycerides in adipose tissue or as a result of the action of lipoprotein lipase during uptake of plasma triglycerides into tissue. NEFA are found in combination with serum albumin in concentration varying between 0.1 and 2 µEq/ml plasma and comprise the long chain fatty acids. Digestion and Absorption fat As fats are non-polar and immiscible with water, its digestion principally differ from the digestion of carbohydrates and proteins. The object of lipid digestion is to arrange the lipids in a form that water miscible and can be absorbed through the microvilli which are covered by an aqueous layer. The sequence of events in lipids digestion are, Lipolysis (=hydrolysis of lipids) Micellar solubilization of the lipolytic products Uptake of the solubilised products by the intestinal mucosa Resynthesis of triglycerides in the mucosal cells, and Secretion of triglycerides into the blood There are important difference in the mechanism of fat digestion in ruminant and non- ruminants. Fat digestion in mono-gastric animals There is no enzyme in the saliva capable of attacking fats. In the stomach warming, softening, dispersion and mechanical separation of lipids from the other nutritional occurs. A course fat emulsion enters the duodenum, which is the site of the major process of fat digestion and absorption. Emulsification of fat occurs in the small intestine after contact with bile salts- sodium glycocholate and sodium taurocholate. This process reduces the lipid particle size to 500-1000 A0 (500-1000mµ diameter). The common bile acids such as cholic, taurocholic and glycocholic acids are detergents with sterol nucleus being lipids soluble and the ionized conjugates of glycine and taurine being water soluble. The small size of fat particles allow for greater surface exposure to pancreatic and intestinal lipases, which adsorb on the particle surface and attack fatty acids in the 1 and 3 (a) position, resulting in hydrolysis of triglycerides to β-monoglycerides and free fatty acids (FFA). The β-monoglycerides and FFA then combine with salt-phospholipids- cholesterol micelles in about a 12:4:2.5:1 molar ratio to from mixed micelles for efficient absorption. The fatty acid in β(2) position are more likely to be absorbed as monoglycerides which has higher absorbability than saturated free fatty acids. Digestibility of fatty acid decreases when the length of carbon chain increases. Micelles and water-soluble aggregate of lipids molecules containing polar group on the outside are in contact with the aqueous phase and non-polar group on the inner side the micelle. The micelles produced in the duodenal lumen are very fine dispersions of lipids in water (50-100 A0 dia) and carry the fatty acids and monoglycerides to the mucosal cells of the small intestine for absorption. Though the formation of micelles is essential for normal fat digestion and absorption, disruption of micelles precedes absorption of their components. The micelles, when coming into contact with the microvillus membrane are disrupted. Bile salts are nor absorbed at the same site as fatty acids and monoglycerides. Absorption of the products of lipolysis occurs primarily in the duodenum and upper jejunum, whereas bile salts are absorbed in the ileum and are re-circulated in the portal blood and hence the bile re-entry to the duodenum. An important property of the lipid-bile salt micelle is to take up significant amounts of non-polar compounds such as sterols, fat soluble vitamins and carotinoids within this lipids non-polar interior. Otherwise these lipids would not be absorbed. Schematic diagram for digestion and absorption of fat Schematic diagram for digestion and absorption of fat Schematic diagram for digestion, absorption and transport of fat Scheme for digestion, absorption and transport of fat Interluminal section of the duodenum showing the initial stages of fat digestion (b) Enlarged section of (a) showing the absorption of micelles Unsaturated fatty acids such as oleic acid and linolenic acids, form mixed micelles with bile salts, whereas the solubility of long-chain saturated fatty acids in bile acid micelles is very low. Monoglycerides and unsaturated fatty acids act synergistically to promote the incorporation of saturated fatty acids into micelles. This effect is shown in young chicks, which utilize saturated fats much better when fed together with unsaturated fat. The major route of fat absorption in mammals and birds is via micelles; in addition, limited amounts of triglycerides may be absorbed intact as a fine emulsion and glycerol liberated by lipolysis is absorbed like glucose by simple diffusion with a carrier. The main products of fat digestion namely monoglycerides and long chain fatty acids enter (after disruption of the micelles) the absorptive intestinal mucosal cells by diffusion (passive transport). Fat digestion in Ruminant animals The mechanism of digestion and absorption of lipids in suckling calves and lambs, where the rumen in non-functional, is the same as that in non-ruminants. The lipids in diets of ruminants are mainly present in an essential form as mono and digalactoglycerides in forage and as triglycerides in concentrate feed. The lipids present in these diets contain a high proportion of polyunsaturated fatty acids in galactolipids of forages and in triglycerides of cereal grains. In the rumen extensive hydrolysis of esterified dietary lipids, triglycerides, galactolipids and phospholipids occurs by the action of microbial lipases, releasing free fatty acids and allowing galactose and glycerol to get fermented to volatile fatty acids. The polyunsaturated fatty acids (linoleic and linolenic acid) released from ester combination are hydrogenated by bacteria, yielding first monoenoic acid and finally, stearic acid. Less than 10% of the polyunsaturated fatty acids usually escape hydrogenation, so that the digestion products reaching the major site of absorption in the upper small intestine are mainly saturated fatty acids (ie.palmitic acid and stearic acid), with major amounts of monosaturated fatty acids (including trans-isomers), very small amount of polysaturated fatty acids and microbial lipids. Both linoleic and linolenic acid present in feedstuffs to plant origin have all-cis double bonds; but before they are hydrogenated, one double bond in each of both the acid is converted to the more stable transform and the latter acids are absorbed by the animal. Though the greatest part of dietary essential fatty acids is destroyed by biohydrogenation, ruminants do not appear to suffer from essential fatty acid deficiency. The small amount of unchanged essential fatty acid passing through the rumen is sufficient for the needs of these animals. Rumen micro- organisms are also capable of synthesizing some odd-chain fatty acids from propionate and branched-chain fatty acids from the carbon skeleton of the amino acids valine, leucine and isoleucine. These acids are eventually incorporated in the milk and body fat of ruminants. Most lipids in the ruminant enter the duodenum as free fatty acids with a very high proportion of saturated fatty acids. Free fatty acids are present in the small intestine of the ruminant in the form of thin layer on the surface of the feed particle. Monoglyceride, which promotes the micellar solubilization of lipids in simple-stomached animals, is removed by hydrolysis in the rumen and is therefore lacking in ruminants. The free fatty acids present in the small intestine of the latter animals are transferred from digesta particles to micellar phase. Micelle formation of saturated fatty acids occurs here with bile salts and lysolecithin. Lysolecithin, which replaces monoglyceride as emulsifying agent is formed from biliary and dietary phospholipids by the action of pancreatic lipase. Resynthesis of triglycerides in the mucosal cells proceeds via the glycerophosphate pathway since no monoglyderide is absorbed from the intestine of adult ruminants. Lipid discharge from the mucosal cells is similar to what occurs in non-ruminants. The poor absorbability of carotene by ruminants may be due to defective micellar solubilisation of this compound. LESSION 6: ROLE AND REQUIREMENT OF WATER Life could not be sustained without water. Just like three-fourth of the globe is covered by water, fresh Plant and animal body record water content of 75 %. Animals may live for more than 100 days without organic food but die in 5 – 10 days if deprived of water. Functions of water 1. As a major component in body metabolism. 2. As a major factor in body temperature regulation. Water and body metabolism 1. All the biochemical reactions that take place in an animal require water. 2. Act as solvent for a wide variety of compounds. Due to this solvent action, it helps in the transport of dissolved nutrients in the system and helps in the excretion of end products of metabolism. Many compounds readily ionize in water. Salts within the body dissociate into ions, which have specific action in body tissues. Most Protoplasm is a mixture of colloids in crystalloids in water. 3. It serves as a carrier of digestive, juices, enzymes and hormones. 4. It is a medium for hydrolysis of the nutrients in the system. 5. It Provides cell rigidity fluid and elasticity.. 6. It serves lubrication fluid in the synovial cavities. 7. It serves as a medium for a) Transportation of semisolid digest in the gastro intestinal tract b) For various solution blood, tissue fluids, cells and secretions c) In excretion such as urine and sweat 8. It provides for dilution of cell content and body fluids so the relatively free movement of chemicals may occur within the cell and in the fluids and GI tract. Thus, water serves to transport absorbed substances, convey them to and from their site of metabolism. 9. In hydrolysis, water is a substrate and in oxidation, water is a product. Water and Body temperature regulation High specific heat, high thermal conductivity and high latent heat of vaporization allow, a) Accumulation of heat b) Ready transfer of heat c) Loss of large amounts of heat on vaporization These physical properties of water are enhanced by physiological characteristics of animal’s life like, a. The fluidity of the blood b. The rapidity with which it is circulated in the body c. Large evaporative surface in the lungs and body surface for sweating or panting. d. The ability to allow constricts blood flow away from the body surfaces during cold stress. All these factors allow animals to control body temperature within desired range in most instances. Specific heat of water is higher than any other liquid/solid. Many animals rely on cooling capacity of water as it gives up its latent heat during panting. Because of this great capacity to store heat any sudden change in body temperature is avoided. Water has greater thermal conductivity than any other liquid, this is important for the dissipation of heat from deeply situated regions in the body. Net loss of heat in Bos indicus (steer): In a steer, the loss of heat through sweating, skin (by conduction and convection) and respiratory evaporation is 21, 16 and 5 %, respectively. Water Absorption: InRuminants, water is absorbed through rumen, omasum. Net absorption of water occurs from ileum, jejunum, caecum. Following a meal ↓ More solutes in the digesta ↓ Increase osmotic pressure ↓ Inflow of water into rumen, small gut, depend on amount of fluid consumed prior to, during and after the meal.This mechanism allows the body to maintain optimum consistency of the digesta throughout the GI tract. If fluids are taken without food, absorption is more rapid and complete because of the osmotic relationships. Polysaccharide – pectin ↓ forms gel in gut ↓ hold water ↓ reduce absorption ↓ laxative Any factor promoting diarrhoea, viz., diet ingested, microbial toxin, altered osmotic relationship, may increase the intestinal motility and may lead to reduction in water absorption from gastrointestinal tract. Water sources Water available to an animal’s tissues is derived from (1) drinking water (2) Water contained in feed (3) Metabolic water (4) Water liberated from metabolic reactions (5) Pre – formed water from body tissue catabolished during a period of negative energy balance. Bound water : differs from water in that it is combined with the protoplasm in the cells by either physical or chemical means. Therefore, bound water does not separate easily from protoplasm by freezing at low temperature or by evaporation at high temperature or under dry conditions. So, this bound water is importance with the ability of plants and animals to resist to low temperature and also in draught conditions. The importance of these different source of water differs among animal species, depending on diet, habitat, ability to conserve body water. Some species of desert rodent, antelopes – do not to require drinking water. Sheep will seldom drink water when the forage moisture content is 65 − 70 % or higher. Relationship between water drunk and moisture content of forage (sheep): Water intake (l/kg DM) 3.7 3.6 3.3 3.1 2.9 2.3 2.0 1.5 0.9 Moisture content of forage, % 10 20 30 40 50 60 35 70 75 Water losses Water is lost through urine, faces, skin, sweat and animal products (milk, egg etc.,) from the animal body. Insensible water loss − vaporization from lungs and dissipation through skin Sweat − sweat glands in the skin during warm or hot weather Milk − lactating animals. Whether the water is taken or not the respiration sweating and micturation takes places and body becomes dehydrated so serve thirst causes the animal to drink water. When an animal is thirsty, salivary flow get reduced and dryness of the mouth and throat may stimulate drinking. Mouth – Thirst receptors Thirst response – dehydration → ↑ in osmoconcentration → stimulates cells in hypothalamus (thirst centre) → animal gets drinking behavior Lack of water →↓in ECF → fall in blood pressure → stimulate thirst When there is lack of water, urine output is less. Excretion of urine is controlled by anti-diuretic hormone (ADH) form posterior pituitary. Lack of water → stimulates posterior pituitary → ADH release → ↑re-absorption of water from kindey nephrons. In hydrated animal →↓ADH→less reabsorption → ↑urine output. ADH release is affected and regulated by osmo concentration of plasma↑osmo concentration → ↑ ADH production. Water requirements Water requirements for any class or species of healthy animals are difficult to define because of numerous dietary factor. Environmental factor effects water absorption and excretion. Water consumption is related to heat production, energy consumption and body surface area in non-stressing situations. All environmental temperature that do not result in heat stress, there is a good linear relationship between consumption of dry matter and water. Non-heat stressed non-lactating cattle may drink water at the rate of 5 − 6 % of its body weight per day. Water consumption may increase by 12 % or more of body weight per day during heat stress. Water requirements and ratio of water to dry matter intake: Animal Beef Dairy Sheep/ Horse Swine Chicken Turkey Cattle Cattle goat Litres/day 22-66 38-110 4-5 30-45 11 -19 0.2-0.4 0.4-0.6 Water:DMI 4:1 4:1 2.5:1 to 3:1 2 to 2.5:1 2 to 3:1 2 to 3:1 3:1 Animals will consume 2 to 5kg of water for every dry feed consumed when they are not heat stressed. Birds require less water than mammalian sp. Young animals generally require more water than adult per unit of body weight. Factors modifying water requirements 1. Physiological status of animal: Young calves – more water / DM intake. Heifers – on the day of heat – 50% more water. Pregnant – embryonic fluid/fetal growth. Lactation – 0.85kg water/kg of milk. 2. Ambient temperature 3. Relative humidity, wind velocity, Rain fall 4. Dry matter intake 5. Composition of feed a) high salt → ↑ H2O intake b) High mineral → ↑ urine excretion c) High protein → uric acid, urea → ↑ water requirement d) High fibrous feed → ↑ water needed 6. Variation of species 7. Frequency of water 8. Diurnal and seasonal variation Effect of water restriction water restriction Effect Moderate water ↓ feed intake,↓ productivity restriction ↓ urine and faecal water excretion Severe water rapid weight loss restriction ↑ renal excretion of Na+, K+ and N ↑pulse,↑ rectal temperature especially at hot temperature because animal no longer has enough water to evaporate ↑ blood concentration Loss of intra cellular fluid (ICF) and extra cellular fluid (ECF) Nausea, difficulty in muscular moments, highly irritable prostration and death. Water intoxication as a result of sudden intake of large volume after a short time period of deprivation (calves). Death may occur due to slow adaptation of the kidney to the sudden high water load. Water quality Animal can tolerate higher salinity than humans. Low quality water increases water intake which in turn reduces feed consumption and production. Toxic substance without effect of palatability are nitrate and fluoride. Element Safe upper Element Safe upper Element Safe upper limit (mg/l) limit (mg/l) limit (mg/l) Aluminium 5.0 Cobalt 1.0 Nickel 1.0 Arsenic 0.2-0.5 Copper 0.5 Selenium 0.02-0.05 Beryllium 0.1 Fluoride 2.0 Vanadium 0.1 Boron 5.0 Lead 0.1 Zinc 25.0 Cadmium 0.01-0.05 Magnesium 600 Nitrate-N 100 Calcium 1000 Mercury 0.01 Nitrite - N 10 Chromium 1.0 Molybdenu 0.01 Sulphate 7000 unfit for poultry and swine should not be used for pregnantand lactating, horse, sheep and young animals 10000 unfit as drinking water. A nitrate level of 1320 mg/l is tolerable but nitrite level of > 33 mg/l is toxic. A high level of nitrate in water signal bacterial contamination. Nitrate could be reduced by bacteria to nitrite which is a health hazard both for man and animals. LESSION 7: IMPORTANCE OF MINERALS IN HEALTH AND PRODUCTION 1. In animal tissues and feeds, 45 minerals are present in varying amounts and concentrations. Seven elements are in high concentration (>70 mg/kg live weight) in animal body and are termed as macro minerals. They are,Calcium (Ca), Phosphorous (P), Magnesium (Mg), Sodium (Na), Potassium (P), Chlorine (Cl) and Sulphur (S). Fifteen micro elements or trace elements (>70 mg/kg live weight) are essential to fulfil physiological function in the body. They are, Iron (Fe), Copper (Cu), Cobalt (Co), Manganese (Mg), Zinc (Zn), Iodine (I), Selenium (Se), Molybdenum (Mo), Fluorine (F), Chromium (Cr), Tin (Su), Vanadium (V), Silicon (Si), Nickel (Ni) and Arsenic (As). In addition to the 22 essential macro and micro element, plant and animal tissues contain an additional 23 mineral element in low concentrations. General function of minerals a) The main structural components of bones and teeth give rigidity and strength eg. Calcium and phosphorus; Magnesium, fluorine, silicon in bones and teeth also contribute to the mechanical stability of the bones. b) As electrolytes, small fractions of the calcium, magnesium and phosphorus and most of the sodium, potassium and chloride in the body fluid and in the soft tissues. (i) Maintain acid – base balance and osmotic pressure (ii) regulate membrane permeability (iii) Excert characteristic effect on the excitability of muscles and nerves (iv) Salts in the saliva, gastric and intestinal juice and in Rumen fluid is appropriate medium for the action enzymes and growth of microbes c) Essential trace elements are integral part of or components of certain enzymes. Enzyme Element Cytochrome oxidase Cu Carbonic anhydrase Zn Glutothione peroxidase Se d) Essential trace elements are also integral part of biologically important compounds Compound Element Haemoglobin Iron Thyroxine Iodine Vitamin B12 Cobalt 5) Essential trace elements act as cofactors or activators in various biochemical reactions Mineral content of the animal body and serum Ca P Mg Na K Cl g/100g fat free dry matter 1-2 0.7-1 0.05 0.15 0.30 0.1-0.15 Blood serum, mg/100ml 10 4-7 2-3 330 2 370 The proportion of each mineral expressed as fat free DM (100g) is similar among species in adult animals. Each organ is in accordance with its function has a characteristic mineral composition, which is also similar in all mammals. Period of under nutrition and water deprivation shall raise its mineral content (FF DM). Na, K, Cl – content of the body is constant during all stage of development from embryo to full development whereas Mg, Ca, P – content in the embryo – (FFDMB) are only half of the respective content in the adult animal.The levels of macro elements in the blood serum, especially of Ca, Mg, K and Cl are maintained within rather narrow ranges by hormonal control mechanisms independently from the amount provided by food homeostasis. Control systems regulating the mineral balance 1. Rate of absorption of minerals from the digestive tract 2. Rate of their deposition and liberation from body reserves in the bones 3. Rate of excretion via faeces and urine The concentration of essential trace minerals in blood tend to vary since there are no control mechanisms to cope with the greatly varying intake of minor elements with respect to their concentration in blood. Sources of minerals for animals Farm animals derive most of the mineral nutrients from concentrate feed and forages that they consume. Apart from this, Mineral supplements from animal origin (Bone meal) and geological origin (CaPO4, NaCl), Drinking water ( minor source) and Soil contamination of herbage source for grazing animals are source of minerals for animals. Factors affecting mineral content in forage The species of the plant The composition of the soil in which the plant grows The stage of maturity Climatic conditions Agricultural treatment (application of fertilizer, irrigation) The influence of varying soil conditions on the uptake of mineral by the plant Mode and site of absorption of minerals Minerals are mainly absorbed as ions. The major site for absorption is small intestine and anterior part of the large intestine. In ruminants, absorption is through rumen well. Large amounts of minerals entering the digestive tract in digestive juices are reabsorbed together with those originating directly from the food. Effects of deficiencies and imbalance of minerals on animals and their prevention Ingestion of diets that are deficient, imbalanced or excessively high in certain minerals induces changes in its concentration in the animal’s tissue from below or above the permissible limits affecting physiological function. It is exhibited as,Retarded growth, decreased food utilization and productivity and disturbances in fertility and general health. Surplus of ions in the basic medium of intestine may lead to precipitation of inorganic insoluble salts and decreased availability of respective mineral. Eg. Surplus PO4 precipitates Ca ions and surplus Mo precipitates Cu Prevention of mineral deficiencies and imbalances: Supplementation with concentrated source of one or more mineral elements Suitable mineral mixture and mineral licks Treatment of drinking water with soluble salts and Injection of slowly absorbed organic compounds Appropriate fertilizer treatment of the soil to improve mineral composition of herbage. LESSION 8: IMPORTANCE OF MACRO MINEALS CALCIUM AND PHOSPHORUS Regulation of Ca, P metabolism and its homeostasis Food Soft Tissues Skeleton (storage) Blood and body fluids faeces Urine Milk Decreased dietary supply of Ca increased Ca requirement Low serum calcium Increased mobilization of calcium form

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