Animal Nutrition Maria Asela B. Sebido Introduction • Successful animal production depends on proper feeds and feeding to the animals • Feeds account for more than 50% of the total cost of production (feeds, stocks, medicaments, labor and depreciation aong others) • Type, quality and availability of feeds depends on characteristics climatic conditions • Philippines is a tropical country – located in the region of the Earth between the latitudes 30 degrees north and 30 degrees south • Characteristics by a wide variability in climatic conditions, ranging from desert with zero rainfall, to tropical forests with annual rainfall exceeding 1,000 cm. • Precipitation is very variable caused several agro-climatic zones according to rainfall amount, frequency and distribution. • Climatic differences influence the type and number of animals to raise, brought about by the availability, type and quality of feeds in these areas. Terms • Nutrition - the series of processes by which an organism takes in and assimilates food for promoting growth and replacing worn-out or injured tissues; encompasses several fields of discipline like biochemistry, chemistry, physiology, endocrinology, microbiology, genetics • Nutrients – any feed constituents, or group of feed constituents of the same general chemical composition that aids in the support of life; may include synthetically produced vitamins, chemically produced inorganic salts or biogenically synthesized amino acids • Digestion – breakdown of feed particles into suitable products for absorption, may include mechanical forces, chemical action, enzyme activity • Absorption – transfer of substance from gastro-intestinal tract (GIT) to the circulatory (blood, or lym,ph) system • Metabolism – combination of anabolic and catabolic reactions occurring in the body with the liberation of energy • Enzymes-complex protein produced in living cells that causes changes in other substances within the body without being changed itself (organic catalysts Factors to consider in selecting the right feeds to use • Feed availability • Determines the type of feed the farmer can offer to animals • Feed suitability • Nutritional value of feed relative to the needs of the animals • Presence of possible toxicity • Presence of undesirable components in the feeds • Feed economics • Use of the existing price per unit of feed for a least possible cost without sacrificing nutritional value of the feeds Adoption of potential feeding technologies differs: • Small hold animal production • Provision of the appropriate level of nutrients to obtain optimum animal performance is lower in the list • Do not consider much the average daily gain, length of feeding time, feed efficiency and consider much the production cost efficiency • Medium and large scale animal production • More receptive to new feeding technologies Feed nutrients and their utilization • Nutrients • Substances contained in the feed that when ingested are digested, absorbed and utilized to sustain animal body processes. • It has four functions: • • • • Provide energy for various processes in the body Serve as structural component Supply raw materials for synthesis of body substances Regulate body temperature Partitioning of feed nutrients using the proximate analysis Feeds Moisture Dry Matter Crude Ash Crude protein Crude Fat Organic Matter Crude fiber Nitrogen Free- extract Water • Ranges from less than 10% in very dry feed to 75% (eg. Molasses- 25%, cereals -12-14%, brewer’s spent grains – 85%, aquatic plants – 90%) • Functions includes: • Universal solvent • Cheapest and most abundant nutrient • Important in biochemical reactions in animal body • Body temperature regulation-dissipating body heat produced during metabolism • Maintains body form, structural constituents of the body • Animal body has 70% water, decreases as animal gets older and 10% water loss is fatal • Found in the animal body as: • Intracellular water – mainly muscles and skin • Extracellular water – mainly interstitial fluids, blood plasma, lymph, synovial and cerespinal fluids • Water present in urinary and gastro-intestinal tract • Functions • • • • • Transport of nutrients and excretion Chemical reactions and solvent properties Body temperature regulation Maintain shape of body cells Lubricates and cushions joints and organs of the body cavity • Deficiencies or restrictions • Reduced feed intake and reduced palatability • Weight loss due to dehydration • Increased secretions of nitrogen and electrolytes such as Na and K • Sources of water in the animal • Drinking water – consumption affected by many factors • Climatic condition • Function of the animal • Dryness of the feed • Water contained in or feed – about 8 to 30% water • Metabolic – may account for 5-10% total water intake • Water losses from the animal body • Urine • Feces • Vaporization from lungs\sweat from the sweat glands Carbohydrates • Composed of C (40%), H (7%0, and O (53%0 by % molecular weight • 75% of the total plant dry matter • Include sugar, starch, cellulose and gums • Very little occurs as such in animal body • It make approximately ¾ of plant dry weight and thus the largest part of animal food supply • Formed through by photosynthesis in plants • Fiber components are low at younger and increasing as the plant matures • Seeds and tubers are principal storage of digestible carbohydrates • Lignin is not carbohydrate but affects the availability of other digestible components of plants • Glycogen – animal starch Classification of carbohydrates • Monosaccharide• Pentoses – ribose, ribulose, xylose, xylulose, arabinose • Hexoses – glucose, fructose, galactose, mannose • Disaccharides-two simple sugars • Sucrose – glucose and fructose • Lactose-glucose and galactose • Maltose – glucose and glucose, α 1,4 glycosidic linkage • Cellobiose – glucose and glucose –β 1,4 glycosidic Classification of carbohydrates • Oligosaccharide- less than than ten simple sugars • Polysaccharide- many sugar molecules • Starch –repeating units are maltose • Amylose –straight chained • Amylopectin - branched • Dextrins- partially degraded starch • Cellulose-repeating units are cellobiose; fiber • Mixed polysaccharide-hemicellulose, pectins • Compound or conjugated olysaccharide • Glycolipids- carbohydrates and fats • Glycoprotein- carbohydrate and protein Functions of carbohydrate • Provide energy for various cellular metabolic activities • Ribose and deoxyribose – components of genetic materials (DNA and RNA) • Glycogen – stored carbohydrate in animal tissues • Deficiencies of abnormal metabolism • Ketosis • Diabetes mellitus Lipids • Group of compounds with C (77%), H (12%), O (11%) with more Carbon and hydrogen than oxygen • Insoluble in water and soluble in organic solvents (petroleum ether, hexane) • High energy materials – supplies 2.25 more energy than carbohydrates and proteins • Eg – coconut, oil palm, rapeseed, sunflower, soybean • Pork fat – lard and beef tallow - tallow Classification of Lipids Lipids Saponifiable lipids Unsaponifiable lipids Simple lipids Compound lipids Sterols Fats Glycolipids Olis Phospholipids waxes Sphingolipids Cholesterol- fat soluble vitamins and hormones Protaglandins Fats • Composed of fatty acids and gycerol • Common fatty acids • Volatile fatty acids – formic, acetic, propionic and butyric • Higher molecular weight saturated fatty acids – caproic (6C), caprylic (8C), capric (10C), lauric (12C), myristic (14C), palmitic (16C), and stearic (18C), arachidic (20C) • Unsaturated fatty acids – palmitolic acid (16C:1∆9), oleic acid (18:1∆9) linoleic (18C: 2∆9,12), linolenic (18C:3∆9, 12, 15) , arachidonic (20C: 4 ∆5,8, Fat • Fat quality is determined by iodine number • Iodine number – determines the degree of unsaturation of fats, since iodine reacts with double bonds • Saponification value – determined by reacting fats with an alkali, KOH or NaOH-forming soap • The higher the saponifcation value – the shorter the chain of fatty acid • Fat – solid in room temperature and oil is liquid at room temperature • Melting point – temperature when fat liquefies while solidifying point is the temperature when oil solidifies Functions of Fats • Provide energy • Stored body fats like adipose, subcutaneous and mesentery tissue • Provide cushioning effect of various organs of the body • Sources of essential fatty acids –linoleic, linolenic and arachidonic acid • Roles in carrying fat soluble vitamins • Deficiency and abnormal metabolism • Skin lesions, hair loss and reduced growth rate • Ketosis – catabolism of body fat • Fatty liver – abnormal metabolism of liver • Location and natural sources of fat • Animal body • Subcutaneous • Surrounding internal organs • Marbling and milk • Natural sources Proteins • Composed of C (53%), H (7%), O (23%), N (16%), S , P (1%) and other minerals • Composed of amino acids joined by peptide linkage • The number , type and sequence of amino acids determine the quality and type of protein • About 150 amino acid occur in nature, but 20 are nutritionally significant • Proteins are principal constituents of the organ and soft structure at the animal body dietary requirement is highest in the young growing animals and decline gradually to maturity • Proteins are basically large molecules • Structure of proteins • All proteins have one common property, their basic structure is made up of single unit, amino acid • Twenty-two amino acids are commonly found in proteins, they are linked together by peptide bonds • The arrangement of amino acids in the chain helps determine the composition of the protein • The classification of amino acids depends on the number of acidic and basic group that are present • Classification of proteins • Simple (globular) – those yielding only amino acids or their derivatives upon hydrolysis – albumin, histones, protomins, globulins, glutelins, prolamins • Fibrous protein – constitute about 30% of total protein in animal body, connective tissues – collagens, elastin, keratins • Conjugated proteins – those in which simple proteins are combined with non-protein radical- nucleoprotein, lecithoproteins, lipoproteins, mettaloproteins • Protein terminology • True protein – composed of amino acids\non-proteins nitrogen (NPN) – compounds that are not true protein in nature • Crude protein –composed of true proteins and any nitrogenous products, Crude protein = %N x 6.25 • Protein quality – refers to the amount and ratio of essential amino acids present in protein • Essential amino acid – not synthesized in the body or if synthesized, the amount is not enough to meet animal’s needs – tryptophan, isoleucine, methionine, histidine, arginine, leucine, lysine, valine, phenylalanine • Non-essential amino acid – can be synthesized in the body – glycine, serine, aspartic acid, glutamic acid, cystine, cystiene, tyrosine, glutamine, asparagine, proline and hydroxyproline Functions of protein • Provide amino acids for synthesis of body clls and tissues • Body metabolism - Important substances such as hormones, enzyme, heritary transmissions and antibodies • Source of energy (not a desirable function but happens when protein intake is excessive, body lacks energy and amino acid imbalance) • Deficiencies and abnormalities • Symptoms of protein deficiencies – reduced growth rate and feed efficiency, anorexia and infertility • Amino acid deficiency – lack of an important amino acid which result to deamination Vitamins • Organic components of natural food but distinct from carbohydrates, fat, protein and water • Present in foods In minute amounts and effectie the animal body in small amounts • Essential for development of normal tissue necessary for metabolic activity but do not enter into structural portion of body • When absent from the diet or not properly absorbed or utilized, results in a specific deficiency disease or syndrome • Cannot be synthesized by the animal • Known as unidentified growth factors (UGF) • Contain C, H, and O, all Vitamin B except inositol contain N, Thiamine and biotin contain S while cobalamin contain cobalt • Realted substances • Provitamins or precursors – carotene • Antivitamins, vitamin antagonists or pseudovitamins Classification of Vitamins • Fat soluble vitamins • • • • Vitamin A – retinol, retinal and retinoic acid Vitamin D – cholecalciferol Vitamin E – tocopherols Vitamin K – phylloquinone, menequinone • Water soluble vitamins • • • • • • • • Vitamin B1 – Thiamine Vitamin B2 – riboflavin Vitamin B6 – pyridoxine, pyridoxal, pyridoxamine Niacin – nicotinamide, nicotinic acid, niacinamide Pantothenic acid Vitamin B12- cobalamine Biotin, Folic acid, Choline, Inositol, Para-amino benzoic acid PABA) Vitamin C- ascorbic acid Functions of Vitamins • Functions as catalysts, co-enzymes, or cofactors of various metabolic reactions • Few vitamins may have structural functions • Natural feed ingredients contain vitamin but vary in amounts due to feed processing, storage, among others. • Vitamin premixes provide adequate amounts of vitamins in the diet • Play role as regulators of metabolism, necessary for growth and maintenance • Vitamin requirement may also increase in old age due to difficulties in absorption and utilization Vitamin Function and Deficiency Diseases Sources Vitamin A (retinol) Transmitting light stimuli from the retina to the brain, caused night blindness, excessive deficiency will result to xerophthalmia and conjunctivitis. Caused retained placenta, birth of blind. Carotene is precursor of Vit a. Green plants (grasses and legumes) Vitamin D3 (cholecalciferol) and Ergocalciferol (D2) Antirachitic vitamin, function is related to the function of Ca and P. deficiency symptoms are rickets (young) and osteomalacia (old) and hypoparathyrodism Sunlight activates provitamin D (Ergosterol), grazed animals rarely have deficiency. Vitamin E (Tocopherol)) Anti-sterility vitamin , natural antioxidant . Metabolic regulator of the cell nucleus. Related to selenium to prevent muscular dystrophy. Leads to reproductive problems Cereal grains and well prepared hays Viatmin K (Phyyoquinone) Anti-hemorrhagic vitamin. Required in blood clotting through prothrombin formation. Can be synthesized in the intestine, deficiency result to prolonged blood clotting or hemorrhages. Green forages and well cured hays. Vitamin Function and Deficiency Diseases Sources Viatamin B1 (Thiamine) Coenzyme in energy metabolism. Deficient animals show general weakness and low appetite resulting to poor growth. Results to beri-beri Cereals, rice bran (tikitiki) Vitamin B2 (Riboflavin ) Functions in several enzyme systems related to protein and energy metabolism. Deficiency diseases – dermatitis and slow growth Milk and milk products, green forages and hays Niacin (Nicotinamide) Important in enzymes systems related to Most feeds contains carbohydrates, protein and fat metabolism. niacin except cereals Dermatitis, retarded growth, and pellagra (black tongue disease) Vitamin B6 (Pyridoxine) Coenzyme in amino acid and fatty acid metabolism . Deficiency signs are poor growth, anemia and convulsion Feed of vegetabe origin Pantothenic acid Component of coenzyme. Needed in various activation reactions on metabolism of nutrients . Deficiency sign is “goosestepping” gait in pigs Various feeds Vitamin Function and Deficiency Diseases Sources Biotin Involved in carboxylation reactions and fatty acids synthesis. Deficiency signs are dermatitis and weight loss. Normally synthesized in the intesines Raw egg white contains avidin and when fed to animals, it produces biotin deficiency Folic Acid (Folacin or pteroylmonoglut amic acid) Involved in DNA synthesis particularly in biosynthesis of purines. Involved in transfer of single carbon units in various biochemical reactions . Deficiency signs – anemia and growth retardation, poor egg production Cereals, milk and yeast Choline Important in transmethylation reaction and in fat metabolism in liver. Prevents abnormal accumulation of fats in the liver. Derivative of acetylcholine (neurotransmitter) . Deficiency signs – slow growth and fatty infiltration of the liver, perosis (slipped tendon) in chicks Yeast, liver and cereals Cobalamin (Vitamin B12) Coenzyme in various biochemical Meat meal and reactions (propionic metablism and red fish meal blood cell maturation. Deficiency signs – pernicious anemia. Lack of cobalt causes deficiency in Vit B12 Inositol Still not understood Paraaminobenzoic acid Essential for growth of some microorganism responsible for synthesis of other vitamins in the rumen Vitamin C (Ascorbic acid ) Anti-stress vitamin. Important in formation and maintenance of collageneous intercellular material. Involved in hemapoesis and hydroxylation of praline and lysine. Prevents scurvy Widely distributed in feeds General Symptoms indicative of marginal or advances vitamin deficiencies in poultry, pigs and ruminants Poultry Vitamin Deficienhatcahbility reduced or below full potentailcy Nervous disorder such as convulsion A,E,B1,B2,B6, Fol Skin and mouth lesions A,B2,B6,H,PP and Pant Discharge from eyes or swollen, pasted eyelids A and Pant Reduced resistance to infectious diseases A,E,B2,B6, Pant and C Poor feathering A, D. B6.H. Fol, PP and Pant Bone abnormalities A, D, H, FOL and PP Leg weakness or paralysis A, D, E, B2. B6 and H Egg production reduced or below full potential A, D,.E, K, B1, B2, B6. B12, H and Fol Retarded growth A,E,K,B1,B2,B6,B12,H, Fol, PP,Pant,C Hatchability reduced or below full potential A,d,b2,b6,b12,h,fol and pant Pigs Retarded growth Muscular incoordination or other nervous signs A, D, B6,B12, and Pant Reduced feed intake A, D, B1, B2, B6, B12, H, Fol, PP Impaired vision and blindness A, B2 and B6 Scours and/or vomiting B1, B2, B6, B12 and PP Haior, skin, and claw problems A, B2, B6, B12, H, PP, and Pant Anemia E, K, B6, B12, Fol, PP and Pant Impaired feed conversion B1, B6, B12, H, PP, and Pant Lameness or unsteady gait A, D, E, B2, B6 and Pant Poor reproduction A, E$, B2, B12, h, Fol and Pant Retarded growth A., D, E, B1, B6, B12, H, Fol Ruminants Muscular in coordination or other nervous signs A and B1 Reduced feed intake A, D and PP Impaired vision or blindness A Digestive disturbances A and B1 Rough hair coat A Degeneration of heart and skeletal muscle E Poor reproduction A, D Retarded growth A,D and E Bone deformities or swollen joints A and D Requirement for Maintenance • Each animal has a maintenance requirement for feed/ration on the various nutrients for the following purposes • Maintain body weight or size(no gain or loss) • Support the essential life processes – respiration, circulation normal muscular activity • Maintain body temperature • Maintain the different body secretions • Basal metabolism or fasting catabolism refers to minimum energy expenditure to maintain essential life processes • It is the starting point in determining the maintenance requirement for energy of an animal • Basal metabolism (BM) is measured in kcal and can be estimated using the formula • BM (kcal) = 70Wkg0.75 , where Wkg0.75 = animal’s body weighti n kg, Wkg = is the body weight raised to ¾ power • It has been established that each animal has a fairly constant BM per unit metabolic body size (MBS) which is equal to 70 kcal • Energy requirement for maintenance is related to the body surface area or metabolic body size i.e ¾ power of the liveweight • It is made up of the net energy (for basal metabolism) and a so called “activity increment” • The activity increment refers to the energy expenditure due to normal body movement and associated activities • Eg. For chicken + 50 %; cattle and swine +20-30%; grazing cattle, another +40% • Protein requirement for maintenance is made up of two portion • Endogenous urinary nitrogen (EUN) – the normal wear and tear of the body organs and tissues. On an energyadequate, N-free diet, EUN is about 2 mg N per basal kilocalorie • The “adult growth” functions i.e feathers, hairs, hoofs, nails Requirement for Growth • Growth is the correlated increase in the mass of the body to reach the size at maturity fixed by heredity • in practical terms, growth is reflected in increased weight and size. It is characterized by: • Increase in the number of cells • Increase in size of the cells. It consist primarily of the build-up of skeletal structure, the muscles and organs and fat tissue • Nutritionally, it means largely increase in minerals (mainly Ca and P) and protein • Protein requirement for growth • High protein level and good protein quality (essential amino acid make-up) are both needed for optimum growth • These may gradually be lowered with age\for example, broiler starter and pig starter mashes may require more than 20% protein (with good quality protein feeds like fish meal, meat meal, soybean meal, skim milk powder) whereas the hog/finisher mash may contain only 14% protein (with little amount of the good quality protein feeds) • Energy requirement for growth • Energy (coming mainly from carbohydrates, provided also by fats and protein) is the driving force for tissue synthesis • Even with adequate amino acid, minerals, and vitamins • Growth cannot take place at the optimal rate without sufficient energy (measured either as kcal of gross energy, digestible energy, metabolizable energy or net energy or as TDN, total digestible nutrients) • Ways of energy restriction – to limit the energy intake of an animal, either or both of these ways may be followed: • Limit the total feed intake • Lower the energy content or density of the ration i.e make the ration bulky • The first method would be to lower the intake of the other nutrient relative to the animal’s requirement • In second method you may still enable the animal to consume adequate levels of the other nutrients in spite of the energy restriction up to a certain point • The energy:protein ratio is an important factor in the efficiency and economy of growth • Growth rates and feed efficiency • The practical measures of growth performance of farm animals are average daily gain in weight (ADG) and feed efficiency (F/G) • The values are greatly affected by two factors: • Hereditary (particularly the breed or stain of the anima) • Environment (particularly by the nutrition and management) • Example • • • • Growing pigs (improved crossbreed) – ADG 0.4-0.6 ; F/G 2.5 – 3.5 Growing cattle (native; ADG 0.4 – 0.5 ; F/G 11-12 Growing cattle (native –Zebu grades) ADG – 0.5 – 0.7; F/G 10-11 Broilers ADG – 1.5 to 1.8 (6-7 weeks0;mF/g = 2-2.3 Requirement for Reproduction • The nutrient requirement for reproduction represent the additional amounts of the various nutrient needed for: • The female’s coming into estrus; subsequent conception and adequate development of the fetus until birth • The male’s maintenance of the integrity of the reproductive organs and its sperm cells and sex hormones • The substantial requirement, especially of energy, proteins, calcium, and phosphorus is for the development of the fetus (prenatal growth, but considered part of reproduction requirement of the dam) particularly during the last quarter of the gestation period • Too severe nutrient deficiencies for a long period can lead to permanent sterility. However, the usual cases are those of not too severe nutrient deficiencies giving rise to low fertility manifested by the following symptoms: • Cessation of estrus • Resorption of fetus • Abortion • Birth of dead or weak young • The principal nutrient deficiencies involved in these symptoms are proteins, calcium, phosphorus and vitamin A Requirement for milk Production • Lactation requires substantial nutrients for synthesis of adequate amount of milk to nourish the young • This additional requirement above those for maintenance and possibly growth in the case of still growing breeding female is much more pronounced in the dairy cow • Dairy type animals produce milk for human consumption and relatively very much less for the nourishment of their young • Good dairy cows in the temperate countries such as the US yield about 25-30 kg milk dairy in a 305 day lactation period • Relatively good dairy cows in the Phil and in most of the tropics correspondingly yield only about 8-12 kg daily • Genetics and climate (direct and indirect effect) have much to do with this difference Minerals • Inorganic substances needed in smaller amounts compared to carbohydrates, fats and proteins • The toital mineral content of plants and animals is often called as ash • Make up to 5% of animal body on dry weight basis • Can be classified as: • Macrominerals (% or g/kg) – calcium, phosphorus, magnesium, sodium, chlorine, potassium, and sulfur • Micromineral (mg/kg or μg/kg) – iron, iodine, chromium, cobalt, copper, selenium, manganese, flourine and zinc. • General functions • Skeletal formation and maintenance – Ca,P, Mg, Cu, Mn • Function in protein synthesis – P, S, Zn • Oxygen transport – Fe, Cu • Fluid balance – osmotic pressure – Na, K. Cl • Regulating acid – base balance of the entire system – Na, Cl and K • Activators and/or components of enzyme systems – Ca, P, K, Mg, Fe, Cu, Mn, Zn • Mineral-vitamin relationship – Ca, P, Co, Se Mineral Function and Deficiency Disease Source Calcium (Ca) Most abundant element I in the body (skeleton). Also important in maintenance of acid-base balance, muscular contraction, blood coagulation, nerve impulse action, and milk secretion. Def. signs, rickets, osteomalacia. Needed in egg production Meat and milk productws, legume feeds, limestone, oyster shell, mono-di and tricalcium phosphate. Phosphorus (P) Bone formation, metabolic processes as component of high energy compound ATP and in enzyme system., acid-base balance, milk secretion . Pica – or depraved appetite common deficiency symptom – animals chewing wood, soil or other materials . Proper Ca:P ration – 1:1 or 2:1 except I in laying birds Animal products and calcium phosphate Magnesium (Mg) Found in skeleton, soft tissues and body fluid. Activator of various enzymes. Deficiency signs – hypomagnesemic tetany (grass staggers in ruminants) Vegetable protein concentrates, yeasts and brans . MgO Potassium (K) Osmotic regulation of body fluids and for Feeds of plant origin acid base balance. Nerve and muscle excitability. Deficiency signs –poor growth, weakness and tetany Sodium Na) and Acid-base balance and osmotic pressure Chlorine (Cl) of body fluids. Chief cations of extracellular fluids. Nerve impulses and absorption of sugar and amino acid in the intestine Chlorine (Cl) Needed in hydrochloric formation. Deficiency signs – increased alkali formation and circulation in the blood due to excess bicarbonate Sulfur (S) Essential in sulfur amino acid (Cystiene and cystine), thaimine and biotin, insulin and metabolite coenzyme A. Needed for bacterial synthesis of sulfur amino acid Table salt , fish meal Iron (Fe) Component of hemoglobin and transferrin and enzyme involved in cytochrome system. Suckling animals must be provided with iron (milk is poor source of iron). Deficiency sign - anemia Feeds of plant origin, fish meal and meat meal Iodine (I) Synthesis of hormones triidothyronine and tetraiodothyronine (Thyroxine) which increase the metabolic rate and promote faster growth by accelerating biochemical reactions in cells and tissues. Deficiency signs – endemic goiter, decrease reproductive capability of animal – birth of weak or dead offspring Most food, cabbage, rape and kale contain goitrogenic compounds Copper (Cu) Component of enzyme cytochrome oxidase –oxidative phsophorylation and oxygen metabolism. Helps in ron absorption. Deficiency signs – poor growth, depimentation of hair and wool, anemia Most feeds except if the plants are grown in copper deficient soils Manganese (Mg) Activator of vrious enzymes involved in metabolims. In chicken – perosis “slipped tendon” disease is observed. Due to malformation of leg bones. Subacute symptoms are poor growth, skeltal malformation, reproductive failures Widely distributed I feeds esp rice bran and wheat pollard Cobalt Co) Associated with Vitamin B12 or cobalamin. Ruminants are sensitive to cobalt deficiency characterized by emaciation, anemia and untriftiness Most feeds have enough cobalt Zinc (Zn) Component of several digestive and metabolic enzymes, such as carboxypeptidases, lactate dehydrogenase, alkaline phosphatase and thymidine kinase. Deficiency symptoms – parakeratosis- reddining of the skin, followed by development of scabs which include inflammation of mouth, stiffness of joints, swollen feet and poor growth Selenium (Se) Component of enzyme glutathione peroxidase- catalyzes the removal of hydrogen peroxide. Deficiency symptoms – myopathy in mammals and exudative diathesis in poultry Molybdenum (Mo) Component of enzyme xanthine oxidase, aldehyde oxidase and sulfite oxidase. No known deficiency symptoms has been described Supplementing the feeds with selenium and vitamin E Digestion, absorption and metabolism • Digestion – digestion involves the processes used to prepare food for absorption • Absorption –includes the processes that move small molecules through membrane of the gastro-intestinal tract into blood so the molecules may be used for their specific function • Digestion included mechanical and chemical processes • Mechanical forces – include chewing (mastication) and muscular contractions of the GI tract • Chemical processes include action of acids produced in the GI tract, and enzymatic activity from enzymes produced in the GI tract or enzymes produced by microorganisms located in various parts of the GI tract Types of GI Tract • Non ruminants- include pig, horse, rabbit, dog, cat and man • Tongue – grasping food • Teeth – mastication of food • Salivary glands – produce saliva which contain: • • • • Water to moisten food Mucin to lubricate food for easy swallowing Bicarbonate salts to buffer (regulate pH) Salivary amylase to start carbohydrate digestion • Esophagus – muscular tube, allows passage oof food from mouth to stomach • Stomach – the stomach is an muscular digestive organ that has 3 major functions • Storage of ingested feed, • Mechanical breakdown • Production of HCL, enzyme and mucus • It has three major • Cardiac region – cells produce mucus that protects the stomach lining • Peptic gland region – cells produce HCL, pepsin (proteolytic enzyme) and mucus • Pyloric region – primarily mucus producing cells • Small intestine – have 3 divisions • Duodenum – an active site of digestion that receives secretions from the pancreas, liver and intestinal walls • Jejunum – middle section that is involved in nutrient absorption • Ileum – last section – also involved in nutrient absorption • Large intestine • Cecum – first section which relatively large in horses and rabbit – when well developed as in the horse contains many bacteria which produced enzymes that digest fiber • Colon – middle section which is involved in reabsoprtion of water-length is related toi amount of water reabsorption – colon in very long in the desert rat • Rectum – last section • Ruminants – cattle, sheep, - also have one true gastric stomach but additional compartments which evolved for fiber digestion • Rumen – large muscular compartment which fills the left side of the body cavity. The muscular walls secrete no enzyme and are covered by projections called papillae which are required for absorption of nutrients • Functions of rumen • Provide favorable environment for protozoa and bacteria . It contain 25-50 billion bacteria-responsible for a significant pregastric fermentation which produces • Enzymes that breakdown fiber well as starch and protein. It produces volatile fatty acids (propionic, butyric and acetic) which are absorbed via papillae and used as source of energy for animal • Water soluble b vitamins and vit k • Bacterial synthesis of amino acid and protein. • Bacteria will pass out of the rumen and become a source of amino acids for the host animal • Thus low quality dieatry protein (protein which is low in dietary essentail amino acids0 may become highl quality protein which is high in dietary essential amino acid during rumen digestion • Favorable conditions which are provided in the rumen • • • • • • Anaerobic environment Constant warm temperature Moisture Constant food supply Mixing Removal of toxic end-products • Additional functions of the rumen include • Storage • Soaking • Physical mixing and breakdown • Reticulum • The reticulum and rumen are not completely separated • They are not 2 distinctly separate compartments but have different functions • Functions of reticulum • Move food into the rumen or omasum • Collection of dense particles of food and in regurgitation of ingesta during rumination (the process of movement of ingesta back up the esophagus to the mouth for additional mechanical breakdown “chewing a cud) • Omasum – round muscular organ which contains many muscular laminae (manyflies). Functions are • controlling passage of ingesta to lower tract i.e. acts as pump • Reduce particle size of ingesta • absorption • Abomasum – very similar to the true gastric stomach which was described for non-ruminants • General characteristics of abomasum are identical to the gastric stomach of non ruminants • Gland regions of the abomasum correspond to gland regions of nonruminant stomach • Small intestine and large intestine – these areas in ruminant are very similar in form and functions as in the non-ruminant • Additional unique features of ruminant • Esophageal groove – begins with the base of the esophagus and when stimulated by sucking forms a tube which empties into the abomasums • The function is to direct ,milk obtained from sucking to escape microbial digestion in the rumen Rumination • Described as controlled vomiting • A controlled set of contractions of the esophagus, reticulum, and rumen allow ingesta to be regurgitated back up to the esophagus where fluids are swallowed again and additional remastication and reswallowing of solids occurs Eructation • Belching of gas • Allows for removal of large volumes of gas produced in the rumen • In eructations, contractions of the upper part of the rumen force the gas up the esophagus and from there the gas penetrates into the trachea and lungs Avian GI Tract • Mouth does not contain teeth, but beak used to collect particles of feed and to break some large particles into smaller pieces • Tongue and salivary glands and saliva does contain salivary amylase • Esophagus – include an enlarged area called the crop • Temporary storage and moistening • Salivary amylase work • Microbial fermentation in some species • Proventriculus – corresponds to the true stomach as described by the non-ruminant and abomasums for ruminants • Site of HCL and pepsin production in the bird • Passed the food very rapidly – 14 seconds • Ventriculus – gizzard – muscular area which contain grit • Muscular contractions which are involuntary aid in the mechanical breakdown of food-similar to the mastication by the teeth in the non ruminant and ruminant • Small intestines – similar to small intestine of non ruminant and ruminant • Large intestine- contains 2 areas called ceca which are very similar in form and function to the cecum of nonruminant and ruminant Nutrient Digestion Nutrient Basic unit protein starch Amino acid Glucose (non ruminant Volatile fatty acid and lactic acid (ruminant) Cellulose Sucrose Lactose Volatile fatty acid Glucose and fructose Glucose and galactose Lipids Minerals Vitamins Fatty acids and glycerol Any soluble form Any soluble form Action of enzymes Site of production Enzyme End products saliva Salivary amylase Starch to maltose rumen Microbial cellulase Cellulose to volatile fatty acid Microbial amylase Starch to VFA and lactic acid Microbial proteases Protein to amino acid and NH3 Microbial urease Urea to CO2 and NH3 Stomach, abomasum and proventriculus pepsin Protein to polypeptides pancreas Trypsin Protein to peptides to amino acid Chymoitrypsin Protein to peptides to amino acid carboxypeptidase Protein to peptides to amino acid Absorption • Occurs in small intestine and large intestine • Villi ( very small projections which line the small intestine) are essential for absorption • Large amount of absorption of VFA occurs in the rumen and depends on many healthy papillae (projections which line rumen) • Absorption occurs as the result of diffusion or active transport • Diffusion involves movement of the basic units from areas of high concentration (The GI tract) to area of lower concentration (the blood) Metabolism • Occur after the basic units of the nutrients have been absorbed into the blood • Involved all the chemical reactions performed by the cells to use the basic unit of the nutrients for their specific functions • Glucose for energy or amino acid for protein synthesis • Reaction function in series and are described as pathway or cycles – Embden-Myerhof pathway of glucose metabolism or krebs cycle
