Animal Nutrition and Feeding Module PDF
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Don Mariano Marcos Memorial State University
2020
Chester S. Libong
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This is a module on animal nutrition and feeding for undergraduate students at Don Mariano Marcos Memorial State University. It covers the nutrient composition of feeds and feedstuffs, digestion, absorption, and metabolism of nutrients, and feed formulation and feeding practices of livestock and poultry. The module outlines learning objectives, course requirements, and grading system, highlighting the importance of these factors in animal production.
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DON MARIANO MARCOS MEMORIAL STATE UNIVERSITY North La Union Campus Bacnotan, La Union COLLEGE OF AGRICULTURE ANIMAL NUTRITION and FEEDING CAMC 106 MODULE Chester S. Libong ANIMAL NUTRITION and FEED...
DON MARIANO MARCOS MEMORIAL STATE UNIVERSITY North La Union Campus Bacnotan, La Union COLLEGE OF AGRICULTURE ANIMAL NUTRITION and FEEDING CAMC 106 MODULE Chester S. Libong ANIMAL NUTRITION and FEEDING (CAMC 106) CHESTER S. LIBONG 2nd Sem 2020 Course Outline in ANIMAL NUTRITION AND FEEDING (CAMC 106) COURSE DESCRIPTION The course consists of four (4) modules. The course discusses the nutrient composition of feeds and feedstuff; digestion, absorption and metabolism of nutrients; feed formulation and feeding practices of livestock and poultry. OBJECTIVES At the end of the course, the students should have been able to: 1. Know the nutrient composition and nutritional characteristics of feeds and feedstuff; 2. Discuss the digestion, absorption and metabolism of different nutrients; 3. Understand the nutrient requirements and nutrient utilization of farm animals; 4. Formulate balance rations to meet the physiological needs of farm animals; and, 5. Understand the process of quality control of feeds. R 1. COURSE REQUIREMENTS Regularly attend the class 2. Have active class participation 3. Take the oral and written quizzes 4. Take and pass the required periodical examination; and 5. Submit the required activities and laboratory works before the end of the term GRADING SYSTEM Module Class Requirements - 60% Class Standing, Self-Check, Summative Test Laboratory Activities Midterm/Final Examination - 40% Total 100% COURSE CONTENT Module I INTRODUCTION AND NUTRIENT COMPOSITION OF FEEDS AND FEEDSTUFFS Lesson 1 Definition of Terms related to Animal Nutrition Lesson 2 Classes of Nutrients, their Compositions and Functions Lesson 3 Classification of Feedstuff Lesson 4 Nutrient Requirements for various Physiological Activities Module II EVALUATION OF FEEDSTUFF FOR FARM ANIMALS Lesson 1 Analytical Methods for Nutrient Comparison Lesson 2 Proximate Analysis Lesson 3 Van Soest (detergent) Method of Forage Evaluation Lesson 4 Other Methods for Feed Analysis Lesson 5 Feeding Trial and Digestion or Metabolism Trial Module III DIGESTION, ABSORPTION OF DIFFERENT NUTRIENTS Lesson 1 Digestive System Lesson 2 Nutrient Digestion and Absorption Lesson 3 Metabolism of Absorbed Nutrients Module IV FEED FORMULATION Lesson 1 Guidelines for Feed Formulation Lesson 2 Methods of Feed Formulation Lesson 3 Other Calculation Relevant to Nutrition and Production REFERENCES Books/Lecture Manual Barcelo, P. M, Hufalar, P. V., N.D. Lecture Manual in Animal Nutrition. College of Agriculture, Don Mariano Marcos Memorial State University, Bacnotan, La Union, Philippines. DAYLE, L.H. 1981. Manual in Nutrition and Growth KELLEMS, R.O. 2002. Livestock Feeds and Feeding Maynard, L.A., et al., 1979. Animal Nutrition. Seventh Edition MCDONALDS, P. 2001. Animal Nutrition PONS, W. G. 2005. Basic Animal Nutrition and Feeding PRESTON, Y.R. and R.A. Leng. 1987. Matching Ruminant Production Systems with Available Resources in the Tropics and sub-Tropics. The Philippine Recommends for Livestock Feed Formulation. 1987. PCARRD Technical Bulletin Serie no. 64. Los Banos, Laguna Online Resources: Burns, Donald; Ciurczak, Emil, eds. (2007). Handbook of Near-Infrared Analysis, Third Edition (Practical Spectroscopy). pp. 349–369. ISBN 9781420007374. FAO, n. d., at http://www.fao.org/3/x5738e/x5738e09.htm https://federated.kb.wisc.edu/images/group226/52745/2.CompositionandAnalysiso fFeeds.pdf https://www.daf.qld.gov.au/__data/assets/pdf_file/0004/65254/IPA-Para-Grass- Risk-Assessment.pdf https://www.slideshare.net/drpksinghbvc/proximate-weende-system-analysis-of- feeds-fodder https://www.futurelearn.com/courses/food-fraud/0/steps/10515 https://courses.ecampus.oregonstate.edu/ans312/one/feed_3_story.htm https://doctorlib.info/physiology/medical-physiology-molecular/46.html https://www.cost-infogest.eu/content/download/3525/32756/file/Adam https://www.stemlittleexplorers.com/en/how-to-demonstrate-diffusion/ https://www.assignmentpoint.com/science/biology/active-transport.html https://med.libretexts.org/Courses/American_Public_University/APUS%3A_An_Intr oduction_to_Nutrition https://www.khanacademy.org/science/biology/cellular-respiration-and- fermentation/glycolysis/v/glycolysis https://www.foodfurlife.com/what-is-digestibility-and-why-does-it-matter.html#/ Hutjens, M., 2019. Feed Efficiency ans Its Impact to feed Intake. Department of Animal ScienceUniversity of Illinois, Urbana Khanna, A., 2020. The TCA Cycle. At https://teachmephysiology.com/biochemistry/atp-production/tca-cycle- Lewis, S., Ullrey, D., Barnard,. D and Knapka, J,. 2006. Nutrition. The Laboratory Rat (second edition). American College of Laboratory Animal Medicine Makkar, H.P.S. 2016. Animal nutrition in a 360-degree view and a framework for future R&D work: towards sustainable livestock production. Anim. Prod. Sci. – Perspectives on Animal Biosciences http://dx.doi.org/10.1071/AN15265 Makkar, H.P.S. 2016. Animal nutrition: beyond the boundaries of feed and feeding. Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy. N. A., 2020. Feed Formulation at http://www.poultryhub.org/nutrition/feed formulation/ Nennich, T., 2019. Dry Matter Determination. Extension Dairy Specialist Texas A&M University Sapkota, A., 2020. Glycolysis- definition, equation, enzymes, 10 Steps with diagram. At https://microbenotes.com/glycolysis/ USNRC, 1984. Nutrient requirements of poultry, 8th revised edition, National Research Council, Washington, D.C. 1 MODULE I INTRODUCTION AND NUTRIENT COMPOSITION OF FEEDS AND FEEDSTUFFS Lesson 1 Definition of Terms related to Animal Nutrition Lesson 2 Classes of Nutrients, their Compositions and Functions Lesson 3 Classification of Feedstuff Lesson 4 Nutrient Requirements for various Physiological Activities 2 MODULE I INTRODUCTION AND NUTRIENT COMPOSITION OF FEEDS AND FEEDSTUFFS INTRODUCTION This module enables to introduce, understand and apply basic concepts in teaching animal nutrition and feeding in the primary grades. It is expected that the content lessons on this module will enable you to gain knowledge and skills in teaching animal nutrition and feeding. OBJECTIVES After studying the module you should be able to: 1. define and understand term related to animal nutrition. 2. appraise the nutrients and it’s source. 3. justify the important role of feed nutrients in the whole process. 4. learn and understand the functions of different nutrients in animal production. 5. learn and understand how proximate feed analysis is done in different feedstuff. DIRECTIONS / MODULE ORGANIZER There are four lessons in the module. Read each lessons carefully then answers the self-check/activity/summative test to find out how much you have benefited form it. Work on these exercises carefully and submit your output to your subject professor. In case you encounter difficulty, discuss this with your subject professor during the scheduled face-to-face meeting. Good luck and happy reading!!! 3 LESSON 1. DEFINITION OF TERMS RELATED TO ANIMAL NUTRITION Animal nutrients are provided by food. Nutrients are essential for growth and maintenance of the body even some nutrients provide energy. Macro nutrients and micro nutrients both are essential for health. For example nutrition for dogs they need carbohydrates, proteins, and fats in order to gain energy. And for Poultry nutrition should include fats, amino acids, proteins, minerals and water for their growth and development. And for Bovine nutrition should need proteins, phosphorous and pro vitamin A. Water soluble vitamins like B-complex vitamins and c vitamins and Fat soluble vitamins like A, D, E and K are the examples for micro nutrients. Animal nutrition focuses on the dietary needs of domesticated animals, primarily those in agriculture and food production. Meeting livestock nutritional requirements is extremely important in maintaining acceptable performance of neonatal, growing, finishing and breeding animals. Animal Nutrition is the science that deals with food or feed and the nutrient it contains. This includes the process of providing body cells with the proper amount and balance of nutrients to enable the cells to function in many metabolic and endocrine process involved in growth, maintenance, work, production (meat, milk, wool and egg), reproduction and the optimal formation of the body’s defence mechanisms against diseases. Related Terms: Nutrients are substances compounds or elements found in feeds that are necessary to support normal life processes of the animals. This includes Carbohydrates, proteins, fat/lipids, minerals, vitamins and water. Feed/Food term given to any materials that embraces both plants and animals including their by-products that provide nutrients to the animals Diet it is the kind of feed/food given to the animals regardless of whatever with balance or unbalance nutrients. Ration the feed given to the animals with balance nutrients needed by the animals within 24 hours. Digestion breakdown of feed/food particles into suitable products for absorption, this includes mechanical, chemical or enzymatic processes. Absorption transfer of digested nutrients from the gastro-intestinal tract (GIT) to the circulatory system (blood or lymph) 4 Metabolism combination of anabolic and catabolic processes occurring in the body of animals with the liberation of energy Enzyme a complex protein produced in living cells that cause changes in other substances within the body without being changed itself (organic catalysts). Anabolism a process of constructive metabolism in which simple substances are converted into more complex substances by living cells Catabolism a process of breaking down of complex substances into more simple compounds by living cells ADF (Acid detergent fiber) - the fraction of a feedstuff not soluble by acid detergent; roughly comparable to a crude fiber plus lignin Antioxidant - a substance that inhibits the oxidation of other compounds. Calorie - The amount of energy required to raise the temperature of water from 14.5° to 15.5°C. Crude protein - total ammoniacal nitrogen x 6.25, based on the fact that feed protein, on the average, contains 16% nitrogen; many non-protein nitrogen compounds may be included. Crude fat - the portion of a feed (or other material) that is soluble in ether; also referred to as ether extract. Crude fiber - The fibrous, less digestible portion of a feed Dry matter - the portion of a feed or tissue remaining after water is removed by drying in an oven. Metabolizable energy (ME) - digestible energy minus the energy of the urine and combustible gases from the gastrointestinal tract (primarily methane) NDF - Neutral detergent fiber, the fraction containing mostly cell wall constituents of low biological availability NFE (nitrogen-free extract) - Consists primarily of readily available carbohydrates such as sugars and starches; part of the proximate analysis. Non-protein nitrogen (NPN) - Anyone of a group of N-containing compounds that are not true proteins that can be precipitated from a solution; ammonia and urea are examples. Digestible Energy (DE) - provides an indication of the actual amount of energy from a feed that can be available for use by the animal. It is estimated by subtracting energy lost in the feces (fecal energy or FE) from the gross intake energy (GE), (i.e., DE = GE – FE). Digestible energy is commonly used to evaluate poultry and horse feed. For poultry feed, DE is considered as an appropriate measure of feed quality, because FE is almost the sole form of energy loss during digestion. However, in horses, given that FE only partially accounts for the energy losses (considerable losses also occur via urine and gases) in the process of the utilization of nutrients, DE may over-estimate low quality feeds relative to high quality feeds. Digestibility - refers to the extent to which a feedstuff is absorbed in the animal body as it passes through an animal’s digestive tract. It varies greatly with the type of feedstuff and type of animal concerned. 5 Digestible Dry Matter (DDM) or Dry Matter Digestibility (DMD) - is the portion of the dry matter in a feed that is digested by animals at a specified level of feed intake. There is no direct laboratory method for measuring DDM/DMD. It is often estimated by measuring in vitro or in situ digestibility. Both of these analyses are rather expensive and laborious. So, in vitro digestibility is frequently estimated by near infrared reflectance (NIR) analysis and/or estimated from the acid detergent fiber. The DDM can be calculated as follows: %DDM = 88.9- [0.779 × %ADF (on a dry matter basis)]. Dry Matter Basis - indicates the nutrient levels in a feed sample based on its dry matter content (i.e., excluding its water content). This is also referred to as “Dry Ba-sis,” “Dry Results” or “Moisture-free Basis.” As there is considerable variation in the water content of forages, excluding the water or expressing the nutrient levels on a dry matter basis eliminates the dilution effect of the water, thereby providing the essential common basis for direct comparison of the nutrient contents across different forages. Dry Matter Intake (DMI) - is the amount of (or prediction of the amount of) dry matter consumed by the animal and is a central concept to any discussion of animal nutrition. Typically, intake increases as the digestibility of the for-age increases. However, anti-quality components such as tannins and alkaloids in feeds and forages may de-crease intake. Scientists have consistently observed that as the percent of neutral detergent fiber (NDF) increases in the feed, animals consume less (i.e., DMI is less). Gross Energy (GE) - refers to the total energy in a feed before accounting for losses due to normal digestive, metabolic and productive functions. It is determined by measuring the amount of heat produced when a feed is completely oxidized in a bomb calorimeter. It is not a very useful measure since the gross energy in most common feeds is about the same, but they do not result in similar animal performance. For example, GE in oat grain = GE in oat straw. Metabolizable Energy (ME) - equals the gross feed energy minus the energy lost in the feces, urine and gaseous product of digestion: ME = GE – FE (energy in feces) – (energy in urine) – (energy in gases) ME = DE (digestible energy) – (energy in urine) – (energy in gases) Because, DE = GE – FE Net Energy (NE) - refers to the amount of feed energy actually available for animal maintenance, growth and production. Conceptually, total NE is the portion of metabolizable energy (ME) remaining after the energy expended in body heat (or “heat increment of feeding”) is deducted, (i.e., NE = ME - heat increment of feeding). Neutral Detergent Fiber (NDF) - is the residue or insoluble fraction left after boil- ing a feed sample in neutral detergent solution. The NDF contains plant cell wall components except for some pectins. The NDF is considered a close estimate of 6 the total fiber constituents of feedstuffs since it measures cellulose, hemicellulose, lignin, silica, tannins and cutins. Total Digestible Nutrients (TDN) - is a measure of the energy value in a feedstuff. The term TDN has its origins in an older system of measuring available energy in feeds and is very hard to measure directly. Today, reported TDN values are calculated, not measured values. Formulas for calculating TDN originally were based on ADF and frequently varied by region and the nutritionist doing the calculation. The National Research Council (NRC) suggested a more accurate and robust procedure of estimating TDN than those based solely on ADF (NRC, 2001). Their procedure is based on the assumption that forage classes (legumes, cool season grasses, warm season grasses, etc.) have more uniform and predictable digestion coefficients. Define the following: (2 points each) 1. Animal nutrition 2. Absorption 3. Digestion 4. Metabolism 5. Nutrients 6. ME 7. DMI 8. Dry Matter 9. TDN 10. NE 7 LESSON 2. CLASSES OF NUTRIENTS, THEIR COMPOSITIONS AND FUNCTIONS In the operation of any animal production enterprises, feeds constitute a large volume of expenses. They account for as much as 80% in animal productions (swine and poultry). Therefore, a good knowledge of feed greatly influences the success or failure of such enterprises. Knowledge on feeds and feedstuff such as when and how to use them for different species and classes of farm animals is important prior to engaging in animal production. Figure 1. Feed Composition and routine laboratory analysis 8 Figure 2. Schematic diagram of the six nutrients I. WATER A. General a. Cheapest and most abundant nutrient. b. Makes up to 65-85% of animal body weight at birth and 45-60% of adult body weight. c. Accounts for 90-95% of blood and many tissues contain 70-90% water. d. Percentage of body water decreases with animal age and has an increase relationship with body fat. e. Found in the animal body as: 1. Intracellular water – mainly in muscles and skin 2. Extracellular water – mainly in interstitial fluids, blood plasma, lymph, synovial and cerebrospinal fluids. B. Functions and Deficiencies a. Functions 1. Transport of nutrients and excretions 2. Chemical reactions and solvent properties 3. Body temperature regulations 9 4. Maintain shape body cells 5. Lubricates and cushion joints and organs of the body cavity. b. Deficiencies 1. Reduced feed intake and reduced feed palatability 2. Weight loss due to dehydration 3. Increased secretions of nitrogen and electrolytes such as Na and K C. Sources of Water in the Animal 1. Drinking water – consumption affected by many factors 2. Water contained in or on feed – about 8 – 30% water 3. Metabolic process – may account for 5 – 10% total water intake D. Water Losses from the Animal Body 1. Urine 2. Feces 3. Vaporization from lungs 4. Sweat from sweat glands II. CARBOHYDRATES A. General 1. Made up of C (40%), H (7%), and O (53%) by molecular weight. 2. Include sugar, starch, cellulose and gums. 3. Very little occurs as such in animal body. 4. CHO make up approximately ¾ of plant dry weight and thus the large part of animals food supply. 5. Form by photosynthesis in plants. B. Structure 1. Structure consists of C atoms arranged in chains to which H and O are attached. 2. May contain an aldehyde or ketone group in their structure. C. Functions 1. Source of energy 2. Source of heat 3. Building stone of other nutrients 4. Stored in animal body when converted to fats 10 III. FATS (LIPIDS or ETHER EXTRACTS) A. Functions 1. Energy supply 2. Source of heat, insulation and protection for animal body. 3. Source of essential fatty acids Linoleic (C18:2) and Linolenic (C18:3) apparently cannot be synthesized by animal tissues, or at least not in sufficient amounts to prevent pathological changes and so must be supplied in the diet. Arachidonic acid (C20:4) can be synthesized from C18:2 and therefore, is required in the diet only if C18:2 is absent. 4. Serve as a carrier for absorption of fat soluble vitamins. 5. Storage fuel Contains no water, more compact energy storage substance Contains twice as much energy as carbohydrates 6. Plasma membrane structure 7. Hormone production 8. Myelin sheaths of nerve fibers 9. Bile salts 10. Insulation and cushioning 11. Vitamin D synthesis 12. Production of some blood clotting factors IV. PROTEIN A. Functions 1. Basic structure of animal body (collagen, elastin, contractile protein, keratin protein, blood proteins) 2. Body metabolism – enzymes (digestion process, degradative process, synthesis process) hormones and lipid transport, immune bodies, hereditary transmissions. 3. Source of energy after deamination 4. Muscle contraction 5. Structural components of cellular membranes 6. Major component of connective tissues 7. Emergency fuel source 8. Oxygen binding 9. Major component of blood clotting factors, antibodies, neurotransmitters. 11 V. MINERALS A. Functions (General) 1. Skeletal formation and maintenance (Ca, P, Mg, Cu, Mn) 2. Function of protein synthesis (P, S, Zn) 3. Fluid balance (osmotic pressure and excretion) (Na, Cl, K) 4. Oxygen transport by hemoglobin and myoglobin (Fe, Cu) 5. Regulating acid-balance of the entire system (Na, Cl, K) 6. Activators and/or components of enzyme systems (Ca, P, K, Mg, Fe, Cu, Mn, Zn) 7. Mineral-vitamin relationship (Ca, P, Co, Se) 8. Structure of bones and teeth 9. Component of macromolecules and electrolytes 10. Buffer stomach acid Table 1. Summary on Different Minerals Minerals/Sources Major Functions Deficiency/Symptoms Major Interrelationship and Toxicities Calcium (Milk, Bone and tooth Rickets (young) Vit. D involved legumes, formation, Blood Osteomalacia (adult) absorption and steamed bone coagulation, Tetany bone meal, calcium Muscle Slow growth and deposition, phosphate, contraction, bone development, Excess PO4 ground oyster Nerve functions, Thin-shelled egg decrease shell) Cell absorption, permeability, Excess Mg Enzyme decrease activation absorption, replaces Ca in bone and increases Ca excretion Phosphorous Bone and tooth Rickets (young) Vit. D involved (Milk and egg, formation, Osteomalacia (adult) in renal oilseeds and Phosphorylation, Rough hair coat, pica absorption and hulls cereals, High energy Lowered appetite bone steamed bone phosphate Slow growth and low deposition, meal, Dicalcium bond, PO4 chief utilization of feed Excess Ca and phosphate, anion radical of Lower blood plasma Mg causes 12 Tripoly- intercellular fluid phosphorous decrease in phosphate) Acid base absorption balance, Enzyme synthesis, Released body energy, Part of DNA and RNA Magnesium (All Enzymes Vasodilation, Excess upsets deeds activator Hyperirritability with Ca and P particularly plant primarily in convulsions, loss of metabolism products – leafy glycolytic equilibrium and vegetable and system; trembling, Tetany, cereal grains) Bone formation Lowered appetite (anorexia), Profuse salivation Sodium Major cation of Reduced growth or Salt toxicity (Common salts, extracellular loss weight readily occurs cured meats, fluid where it is Eye disturbance with in non- cheese) involved incorneal lesions, ruminants with osmotic pressure Reproduction levels above and acid-base impairment (infertility 8% in the diet, equilibrium, – males, delayed Staggering Preservation of sexual maturity – gait, blindness normal muscle female) and other cell irritability,Craving of salt or nervous Cell eating of soil disorders permeability, Reduced appetite Component of bile which aids in fat digestion Chlorine Major anion Hydrochloremic (Common salt) involved in alkalosis osmotic pressure and acid-base balance, Hydrochloric acid in digestion 13 Potassium Major cation of Hypokalemia: (Normal rations) intracellular fluid lethargic condition where it is with high incidence involved in of comas and death, osmotic pressure Diarrhea, distended and acid-base abdomen and untidy balance, appearance muscle activity, Heart lesions, Maintenance of Loss weight and electrolytes reduced appetite balance, Muscle weakness Enzyme Poor wool growth activator Sulfur (Protein Sulfur containing Primarily growth supplements, amino acid effect due to sulfur forages, cereals) SH group amino acids function in tissue requirement for respiration protein synthesis Synthesis of Low feed efficiency amino acids in Slow wool growth ruminants Iron (Egg, soil, Cellular Hypochromic- Ca-P ratio forages, grains, respiration microcytic anemia influence iron injection, (hemoglobin) Thumps in pigs absorption liver, ferrous Component of Diarrhea/ loss of Cu required for sulfate) many enzymes appetite proper metabolism Pyridoxine deficiency decrease absorption Copper Cofactor in Fading hair coat o Excess Mo, Zn (Feedstuff, several lack of wool inhibits its CuSO4) oxidation- Nervous symptoms or utilization and reduction atoxia storage enzyme Lameness, swelling of Toxicity (above synthesis, joints, fragility of 250 ppm) Hemoglobin bones synthesis, Anemia Bone Formation, Stunted growth 14 Erythropoises, Diarrhea or ataxic Co-enzymes gait system, Hair Loss condition pigmentation, Aortic pressure in Reproduction, swine and poultry Collagen and Depraved appetite elastin synthesis, iron utilization Zinc (Forages, Cofactor of Poor hair or feather High Ca and P ZnO, ZnCO3 or several enzymes development, Rough level ZnSO4) systems and thickened skin or requirement (peptidases, parakeratosis, carbonic Anorexia, anhydrase) Hyperkeratosis in chicks Manganese Activator of Poor growth Excess Ca and (Feed, nuts, enzymes Shortened long bones P decreases seeds, milk, systems Impaired absorption legumes and (oxidative reproduction cereals) phosphorylation, (testicular amino acid degeneration in metabolism, males, defective fatty acid ovulation in female) synthesis, Perosis or slipped cholesterol tendon in chicken metabolism) Lower hatchability, Bone formation egg shell strength, (organic matrix) lameness, stiffness Growth and reproduction Cobalt (Cobalt Components of Anemia pellets/salts) Vit. B12 Iodine (Iodized Thyroxine Goiter, still births, hair Chronic toxicity salts, cod-liver less pigs, wool less Blind staggers oil) lambs (10-20 ppm) Alkali disease (5-10 ppm) Acute toxicity (20 ppm) 15 VI. VITAMINS - organic substance essential for the maintenance of health and life of farm animal though needed in very minute amounts. A. Functions 1. Coenzymes for many metabolic pathways 2. Antioxidants 3. Component of visual pigment 4. Hormone (Vitamin D) Table 2. Summary on Different Vitamins Vitamins/Sources Main Function Deficiency/Symptoms Major Interrelationship and Toxicities A Bone formation Xeropthalmia Hyperostosis (Yellow corn, Vision(rhodopsin) Night blindness Hyperkeratosis grasses, egg yolk, Epithelial tissue Hyperkeratosis liver, fish liver oil, (digestive, Skeletal lesions, bone milk fat, green respiratory, remodeling vegetables) reproductive) Reproductive failures Glucose synthesis Muscle Growth or cellular incoordination metabolism Rough haircoat, Proper function plumage of immune system D (Sterol) Bone formation Rickets (growing Decalcification D2 – (Ca, P absorption period) of skeleton, ergocalciferol from renal Osteomalacia calcification of D3 – tubules, (adults) tissue cholecalciferol osteoblast Soft egg shells, (Fish liver oil, formation, reduced egg irradiated yeast, calcification) production, egg yolk, milk fat, CHO metabolism hatchability field cured hays, (phosphorylation) exposure to Growth sunlight, commercial preparations) E (tocapherol) Antioxidants Muscle dystrophy Relatively non- (Cereal grains, Muscle structure Encephalomalacia toxic egg yolk, oils of (dystrophy) Reproductive failures soybeans, Reproduction Liver necrosis peanuts, cotton (seminiferous Cardiac muscle 16 seed, beef liver, tubules) abnormalities wheat germ oil, Hatchability of Dental commercial eggs depigmentation preparations) Cell nucleus activity K Prothrombin Spontaneous Relatively non- (Green leafy (normal blood hemorrhage, toxic plants, liver, egg clotting increase blood yolk, fish meal, formation) clotting time synthetic forms (menadione)) Thiamine (B1) Coenzyme Polyneuritis, Relatively non- (Milk and milk (Thiamine convulsions toxic products, pyrophosphate) Cardiovascular brewer’s yeast, Decarboxylation disturbances wheat germ, of α-keto acids Beri-beri (man) unmilled cereals, Promote normal Anorexia, emaciation grain by- appetite and Hyperirritability products, lean digestion Reproductive failure pork, liver, good Nervous system in horses quality hay, healthy, prevent synthetic forms) irritability Riboflavin (B2) Coenzyme (Flavin Ectodermal and Non-toxic (Milk, cheese, mononucleotide, nervous system lesions liver, kidney, Oxidize Adenine Dermatitis, hair loss eggs, fish, green dinucleotide) Curled toe paralysis forage, oil meals, Dehydrogenase Depressed appetite, fermentation Energy transfer retarded growth products, Protein commercial metabolism preparations) Xanthine oxidase Healthy skin Pantothenic acid Coenzyme A Dermatitis, loss of hair, Relatively non- (liver, egg yolk, (Acyl transfer) graying of hair, toxic milk, hay, peanut spastic gait, goose meal, cane stepping, paralysis molasses, yeast, Enteritis rice, wheat Poor growth, brans, cereal reproduction grains and by- Skin, nervous system, products, royal adrenal gland lesions jellys of bees) Gastrointestinal trouble 17 Niacin or Coenzyme (DPN, Dermattis, diarrhea, Vasodilation Nicotinic acid TPN) dementia with itching and (Milk, meat, eggs, Hydrogen Irritability burning of skin green transport Inflammation, Fatty liver vegetables, Spared by the ulceration of mouth, peanut butter, amino acid tongue, digestive animal and fish tryptophan tract by-products, Health of Vomiting distiller’s grain digestive, nervous Anemia and yeast, system Loss of appetite fermentation soluble, oil meals) Pyridoxine (B6) Coenzyme Convulsions, neuritis, Convulsion, (Yeast, liver, (Pyridoxal hyperirritability death muscle, meat, phosphate) Hypochromic- egg yolk, milk, Amino acid microcytic anemia cereal grains, decarboxylation, Increased excretion vegetables) transanimation, xanthurenic acid removal of sulfuhydryl groups Biotin Coenzyme – Dermatitis Non-toxic (Yeast, organ carboxylase Loss of hair meats, whole Carboxylation Disturbance of grains, molasses, Fat synthesis nervous system milk) Deamination of certain enzyme Folic acid One carbon Macrocytic anemia, Non-toxic (Green leafy carrier leucopenia plants, organ Synthesis purines, Cervical paralysis in meats, cereals, certain methyl turkeys animal by- groups Retarded growth products, Erythropoiesis Poor feathering, soybeans) pigmentation of feathers Choline Methyl donor Fatty liver, kidney Persistent (Milk, egg, meat, Lipotropic degeneration diarrhea fish, fats) substance: Poor reproduction, Acetylchloride, lactation phospholipids Renal tubular Essential in degeneration building Enlarged spleen ,maintenance of Peorsis in chicks cell structure 18 Transmission of nerve impulses Fat metabolism in the liver Cynocobalamine Labile methyl, Macrocytic anemia Non-toxic (B12) purine group Neurological (Milk, meat, fish synthesis disturbances meal, animal by- CHO, fats Hatching problems product, metabolism Reduced growth commercial Isomerization Posterior preparations) reactions incoordination Nucleic acid Unsteadiness of gait synthesis Known as animal protein factor (APF) Vit. C Collagen Scurvy – slow wound Non-toxic (Citrus fruits, formation healing tomatoes, green Formation, Spongy gums leafy materials, maintenance of Swollen joints potatoes, intracellular Hemorrhage synthetic materials in Anemia preparations) bones, soft tissues Loss of teeth Tissue catalyst Antioxidant Related compounds Inositol Lipotropic action Alopecia (Plant products in – rat diets the organic phosphorous substance phytin) Para- Anti-gray-hair Graying of hair aminobenzoic factor on mice, acid (PABA) rats (synthetic Growth stimulant preparation) in chicks Question: (20 points) 19 1. Enumerate the basic classes of nutrients in the feeds and give their functions. LESSON 3. CLASSIFICATION OF FEEDSTUFF Feeding farm animals is a process of priority decision-making involving at least two general conditions. The first is an abundance of food material which is not in a usable form or aesthetically acceptable as human food, and the second is a surplus of food material accompanied by a standard of living sufficiently high that the nutrient losses involved in feeding animals are compensated for by the increased desirability and nutritional excellence of foods of animal origin. Decisions relevant to the first set of conditions include determining the optimum numbers and kinds of animals that can be productively supported by the available feedstuffs. Efforts should be made to maximize production; but also to allocate nutrient supplies in a competitive situation for the maximum benefit to the society concerned. These decisions are among the most critical that civilization faces today. Decisions can be made only on the basis of reliable information concerning the composition of all feed materials used in animal feeding. This information is fundamental in assigning priorities to the use of available feed supplies in animal agriculture (FAO, n. d.). The various feeds and fodders used in livestock feeding are broadly classified as: A) Roughages; B) Concentrates; C) Feed supplements and Feed additives. Roughages – Roughages are the feed stuffs which contain more than 18 percent crude fiber and less than 60 percent Total Digestible Nutrients. Due to higher crude fiber content, they are more bulky and have low digestibility as compared to concentrates. 1) Maintenance type – Containing 3-5 percent DCP e.g. Green maize, oat. 2) Non-maintenance type – containing less than 3 percent DCP e.g. Straw,. 3) Production type – containing more than 5 percent DCP e.g. Berseem, lucerne. (DCP – Digestible Crude Protein) The roughages are further classified into two major group as: 1) Green / succulent roughages – They contain about 60-90 percent moisture eg. Pastures, cultivated fodders, tree leaves, root crops and silages. 2) Dry roughages – They contain about 10-15 percent moisture e.g. Straw, and Hay. Classification of Feedstuff 20 A. Concentrate Feeds – are feed materials usually having low moisture and fiber content (less than 18%) with relatively high digestibility. Concentrates are classified into: i. Basal (carbonaceous) concentrates – those feed materials rich in energy (less than 20% CP) Example: Cereal grains – yellow corn, rice bran (D1), sorghum, barley, oats, wheat pollard Root crops – cassava, gabi, camote Oil/Fats – coconut oil, fish oil, tallow Molasses – sugarcane ii. Protein concentrates – those feed materials either pure or mixed rich in protein either plant or animal origin (more than 20% CP). Example: Plant protein – soybean meal, peanut meal, cotton seed meal, copra meal, ipil-ipil meal, sunflower seed meal, rubber seed meat, etc. Animal protein – meat and bone meal, blood meal, Feather meal, tankage, skimmilk, animal waste Marine protein – fish meal, shrimp meal Single cell protein – produced by yeast or Bacteria Non-protein nitrogen – urea may be fed to ruminants but not for swine or poultry - biuret is a mixture of the nitrogen compounds resulting from controlled pyrolysis (chemical change due to heat) of urea. iii. Minerals and Vitamins Supplements Minerals – (Macro) – limestone, oyster shell, bone meal, Dicalcium phosphate, Tricalcium phosphate, Mono Dicalcium phosphate, calcium bicarbonate, salt; (Micro) – are either synthethic preparations which are available commercially in premixes. Vitamins – are either pure or synthetic preparations which are available commercially in premixes. Feed additives (non-nutritive feed) – feed ingredients with no nutrient value added usually in small quantity to the basic fed mix for the purpose of fortifying to improve its digestion and utilization. Example: antibiotics, prebiotics, probiotics, anti- oxidants, hormones, enzymes, mold inhibitors, flavouring, coloring, toxic binders, pellet binders and acidifiers. 21 B. ROUGHAGES – are feed materials with high proportion of fiber or non- digestible materials (more than 18%) with relatively poor digestibility. Roughages are classified into: a) Degree of Water Content Succulent roughages – high in water content and more digestible Soilage – green fodder that are cut by human and feed to the animal fresh Pasture – green fodder/grasses that are graze by the animal in the field Establishment: cleaning or clearing, land preparation, (plowing, harrowing, furrowing), planting, care and management (weeding, fertilizer application), harvesting (cut and carry or grazing or tethering) Some pasture species (grass or legumes) Napier grass – Pennisetum purpureum Guinea grass – Panicum maximum Para grass – Brachiaria mutica Signal grass – Brachiaria decumbens Star grass – Cynodon plectostachyus Napier Bagocboc – Themeda triadra Cogon – Imperata cyclindrica Alabang X – Andropogon nodosus Centrosema – Centrosema pubescens Para grass Kudzu – Peuraria phaseoliodes Calopogonium – Calopogonium muconiodes Stylo – Stylosanthes guyanensis Pintoi peanut – Arachis pintoi Ipil-ipil – Leucaena leucocephala Kakawate – Glyricidia sepium Silage – grass or crop residues that are being process (compressed and stored under anaerobic condition in a container called silo) thru fermentation before being fed to animals. Dry roughages – contain less water content Hay – are either grasses or legumes consisting of the leaves, flowers and stems being cut and cured either by sun or air drying, by dehydrating green forages to a loisture content of 15% or less. Straw – are mostly from cereal crop residues which contain high percentage of indigestible fiber and are low in digestible carbohydrates, protein, vitamins and minerals b) Level of Contents 22 Proteinaceous roughages – contain more than 10% CP (dry matter basis); made-up primarily of legumes and some immature grass Carbonaceous roughages – contain less than 10% CP (dry matter basis); made-up primarily of non-legumes and low quality roughages. Answer the following briefly. (10 points each) 1. Differentiate roughages from concentrates. 2. Differentiate carbonaceous roughages from proteinaceous roughages. 23 LESSON 4 NUTRIENT REQUIREMENTS FOR VARIOUS PHYSIOLOGICAL ACTIVITIES “Nutrition involves various chemical and physiological activities which transform food elements into body elements.” This simple (Maynard, 1979) definition describes the science of nutrition, a chemistry-based discipline interacting to varying degrees with many of the other physical and biological sciences. This definition also implicates nutrition as one of the environmental factors that influences the ability of animals to attain their genetic potential for growth, reproduction, longevity, or response to stimuli. Therefore, the nutritional status of animals involved in biomedical research has a profound effect on the quality of experimental results. The process of supplying adequate nutrition for laboratory animals involves establishing requirements for approximately 50 essential nutrients, formulating and manufacturing diets with the required nutrient concentrations, and managing numerous factors related to diet quality. Factors potentially affecting diet quality include the bioavailability of nutrients, payability or acceptance by animals, procedures involved in preparation or storage, and the concentration of chemical contaminants (Lewis, 2006). A. MAINTENANCE 1. Each animal has a maintenance requirement for feed/ration on the various nutrients for the following purposes: a. To maintain body weight or size (no gain or loss) b. To support the essential life processes (respiration, circulation, normal muscle activity, etc.) c. To maintain body temperature d. To maintain the different body secretions 2. Basal metabolism or Fasting Catabolism – refers to the minimum energy expenditure to maintain essential life processes. The starting point in determining the maintenance requirements for energy of an animal. Basal metabolism (BM) is measured in kilocalories and can be estimated using the following formula derived from experimental data: 24 BM (kilocalories) = 70 Wkg 0.75 Where: Wkg = animal’s body wt. in kg Wkg0.75 = body wt raised to the 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. Table 3. Portion of body weights and corresponding MBS (Maynard et. al., 1979) Wkg MBS 1.0 5.62 50.0 18.80 100.0 31.62 150.0 42.86 200.0 53.18 300.0 72.08 400.0 89.44 500.0 105.74 1,000.0 177.80 3. Energy requirement for maintenance is related to the body surface area or metabolic body size, ex. ¾ power of the live weight. This made up of the net energy (for Basal metabolism) and a so-called “activity increment” (refers to the energy expenditure due to normal body movements and associated activities. E.g. for chicken, + 50%; cattle and swine, +20-30%; grazing cattle, another + 40%. 4. Protein requirement for maintenance is made up of two portions: a. Endogenous urinary nitrogen (EUN) = the normal wear and tear of the body organs and tissues. On an energy adequate, N-free diet, EUN is about 2 mg N per basal kilocalorie. b. The “adult growth” functions – e.g. feathers, hairs, hoofs, nails, etc. B. GROWTH 1. Growth is the correlated increase in the mass of the body to reach the size at maturity fixed by heredity. 25 In practical terms, growth is reflected in increased weight and size. This characterized by: a. Increase in the number of cells b. Increase in size of the cells. This consists primarily of the build-up of skeletal structure, muscles and organs, and fat tissues. Nutritionally, it means largely increase in minerals (mainly Ca and P) and protein. 2. Protein requirements for growth. High protein level and good protein quality (essential aa 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% CP (with good quality proteins like fish meal, meat meal, soybean meal, skimmilk powder, etc.) whereas the hog/broiler finisher mash may contain only 14% protein (with little amount of the good quality protein feeds). 3. Energy requirements for growth. Energy (mainly from CHO, provided also by fats and proteins) is the driving force for tissue synthesis or anabolism. Even with adequate aa, minerals, vitamins, growth cannot take place at the optimal rate without sufficient energy (measured by kilocalories of gross energy, digestible energy, ME or NE, or as TDN) 4. Ways of energy restriction – to limit the energy intake of an animal, either or both of these ways may be followed: a. Limit the total feed intake b. Lower the energy content or density of the ration – example, make the ration bulky The first method would also lower the intake of the other nutrients relative to the animal’s requirements. In the 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. 5. Growth rates and feed efficiency The practical measures of growth performance of farm animals are average daily gain in weight (ADG) and feed efficiency ratio (FCR). The values are greatly affected by two major factors: a. Hereditary (breed or strain of the animal) b. Environment (nutrition and management). Under Philippine conditions, following are the normal values for reasonably good rations. 26 Category ADG (kg) FCR (kg feed/kg live weight gain) Growing pigs 0.4 – 0.6 2.5 – 3.5 (crossbred) Growing cattle 0.4 – 0.5 11.0 – 12.0 (native) Growing cattle 0.5 – 0.7 10.0 – 11.0 (native x zebu grades) Broilers (modern 2.5 – 1.8 (6 – 7 wks) 2.0 – 2.3 strains) C. REPRODUCTION 1. The nutrient requirements for reproduction represent the additional amounts of the various nutrients needed for: a. Female’s coming into estrus, subsequent conception and development of the fetus until birth. b. Male’s maintenance of the integrity of the reproductive organs and its sperm cells and sec hormones. 2. The substantial requirement, especially of energy, protein, calcium, phosphorous is for the development of the fetus (“pre-natal growth” but considered part of reproduction requirement of the dam) particularly during the last quarter of the gestation period. 3. Too serve nutrient deficiencies for a long period can be lead to permanent sterility. However, usual cases are those of not too severe nutrient deficiencies giving rise to low level of fertility manifested by the following symptoms: a. Cessation of estrus b. Resorption of fetus 27 c. Abortion d. Stillbirth or weak young The principal nutrient deficiencies involved in these symptoms are protein, calcium, phosphorous, vitamin A. D. MILK PRODUCTION 1. Lactation in any species 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 animal, especially the dairy cow. Dairy type animals produce milk for human consumption and relatively very much less for the nourishment of their young. 2. Good dairy cows in the temperate countries like US yield about 25-30 kg milk daily in a 305 day lactation period. Relatively good dairy cows in the Philippines and in most of the tropics correspondingly yield only about 8-12 kg daily. Genetics and climate (direct and indirect effects) have very much to do with this difference. 3. Commercial dairying would generally need intensive grazing management or intensive forage production, compared with extensive pasture or range grazing in cattle ranching for beef production. Dairy cows need improved forages for efficient and economical production. As much of good quality forage that a dairy cow can and should consume, would generally be able to meet only the requirements for maintenance and the production of not more than 5 kg milk daily in the Philippines. Energy rather than CP seems to be more critical problem in meeting adequate needs of the dairy cows in the Philippines. Concentrate would be needed to provide that energy deficit. A common “rule of thumb” is to feed 1 kg of good concentrate mixture for every 2.5 kg of milk in excess of 5 kg if the forage is of good quality. 28 4. Milk constituents and blood sources: Casein Blood amino acids Immune globulins Blood globulins Fat Fatty acids, acetate Lactose Glucose Minerals Minerals in blood Vitamins Vitamins in blood E. EGG PRODUCTION 1. The major factors affecting nutrient requirements are: a. Rate of egg production b. Egg size or weight c. Egg shell thickness d. Body size of layer 2. The principal factor affecting egg shell quality is dietary calcium. Egg shell quality can be measured by specific gravity of egg, shell thickness, shell smoothness, breaking strength, percentage of crack or shell appearance. Low dietary calcium levels, less than 2%, decrease egg shell quality in chickens. 29 3. Portion of nutrient requirements of egg type chicken.*** Nutrients o-6 6-14 24-30 Lying weeks weeks weeks CP, % 19 16 14 17 ME 2,800 2,750 2,700 2,750 Lysine, % 0.85 0.60 0.45 0.65 Methionine, % 0.30 0.25 0.20 0.32 Methionine + Cystine, 0.60 0.50 0.40 0.55 % Ca, % 0.80 0.70 0.60 3.40 Avail. P, % 0.40 0.35 0.30 0.32 *** Source: US NRC, 1984. Nutrient requirements of poultry, 8 th revised edition. National Research Council, Washington, D.C. Answer the following. (10 points each) 1. Younger animals needed more nutrients than adult animals. Justify your answer. 2. Which birds need more nutrient, 45 days old broiler or laying hens? Explain your answer. MODULE SUMMARY In this module you have learned about the nutrient composition of feeds and feedstuffs. Lesson 1 explained the terms related to animal nutrition Lesson 2 identified and discussed classes of nutrients, their compositions and functions Lesson 3 familiarized and collected samples based on the classification of feedstuff Lesson 4 explained and correlate the nutrient requirements for various physiological activities of different stages in life cycle of animals 30 Congratulations! You have just finished and learned many things in this Module I, now you are ready to evaluate how much have you have benefited from your reading by answering the summative test. GOOD LUCK! and ENJOY! SUMMATIVE TEST MULTIPLE CHOICE: Encircled the Letter of the Best Answers. 1. Organic molecules, Except: a. carbohydrates b. lipids c. minerals d. vitamins 2. Substance acts on skeletal formation, Except: a. Ca b. Fe c. Cu d. Mg 3. Promote normal appetite & digestion: a. B1 b. B2 c. B6 d. B12 4. Fat soluble vitamins: a. cyanocobalamine b. pyridoxine c. thiamine d. tocopherol 5. Macro-minerals: a. Cu b. Co c. Na d. Se 6. The feed given to the animals with balance nutrients needed by the animals within 24 hours: a. feed b. nutrient c. diet d. ration 7. Laying hen needed, CP %: a. 14 b. 17 c. 19 d. 16 8. Component of visual pigment: a. vitamins b. minerals c. carbohydrates d. protein 9. Calcium levels which cause decrease egg shell quality in chickens: a. 3.5 b. 3 c. 2.5 d. 1.5 10. Fat soluble vitamins: a. Pyridoxine b. Riboflavin c. Thiamine d. cholecalciferol ENUMERATION: Give the best answers. (30 points) 1. Give the different groups of nutrient found in the ration of swine and their functions. DISCUSSIONS 1) Explain animal nutrition. (10 points) 2) Why is that nutrients are needed during various physiological activities of animals at different stages in their life? (30 points) 31 1 MODULE II EVALUATION OF FEEDSTUFF FOR FARM ANIMALS Lesson 1 Analytical Methods for Nutrient Comparison Lesson 2 Proximate Analysis Lesson 3 Van Soest (detergent) Method of Forage Evaluation Lesson 4 Other Methods for Feed Analysis Lesson 5 Feeding Trial and Digestion or Metabolism Trial 2 MODULE II EVALUATION OF FEEDSTUFF FOR FARM ANIMALS INTRODUCTION This module enables to introduce, understand and apply the feedstuff evaluation in teaching animal nutrition and feeding in the primary grades. It is expected that the content lessons on this module will enable you to gain knowledge and skills in teaching animal nutrition and feeding. OBJECTIVES After studying the module you should be able to: 1. discuss the various analytical methods used to determine the nutrient composition of feedstuff. 2. explain how feed samples should be collected for analysis and how a nutrient composition is reported. 3. describe procedures in determining the apparent digestibility of feedstuffs. 4. describe the various energy measurements and explain their usage in diet formulation or evaluation. 5. describe how feeds can be physically and economically evaluated. DIRECTIONS / MODULE ORGANIZER There are five lessons in the module. Read each lessons carefully then answers the self-check/activity/summative test to find out how much you have benefited form it. Work on these exercises carefully and submit your output to your subject professor. In case you encounter difficulty, discuss this with your subject professor during the scheduled face-to-face meeting. Good luck and happy reading!!! 3 LESSON 1. ANALYTICAL METHODS FOR NUTRIENT COMPARISON Evaluating feedstuffs for use in livestock diets may employ a number of procedures. These procedures should identify nutrient composition, palatability, digestibility and productive value, physical or handling characteristics and provide economic comparisons. Analytical Methods for Nutrient Comparison For many nutrients required by animals there are direct analytical methods by which we can establish the potency of feedstuffs in their nutrients. Three general types of analytical methods: 1. Chemical procedure (gravimetric procedures, titration, colorimetry, chromatography, etc.). 2. Biological procedures (employ animals such as chicks or rat to give a much more accurate estimate of animal utilization but which makes procedure more tedious and expensive) 3. Microbiological procedures (similar to biological procedures but employ isolated bacteria) OBTAINING SAMPLE OF ANALYSIS The key to reliable feed nutrient evaluation is obtaining a sample that represents the feed the animals will eat. A good sample each lot of feed is essential because this small amount, usually less than quart, will probably represent several tons of feed. 1. Identification First step in obtaining samples is recording about the feed. Label each container with your name, address, sample number, feed name and type, stage of maturity and harvest date. Also, note where the sample is stored and any special conditions (color, odor, mold, etc.). This information is useful when formulating rations and aid in predicting value of future samples. 2. Sampling Recommendations: a) Grains or mixed feeds 1. Sacked feeds should be sampled by taking two samples (a handful) 4 each from 5 – 7 different tasks. If a sack probe is available, it should be used. If not, best sample sacked feeds when they are being emptied. 2. Bulk feeds or grain in bins should also have 12 – 15 samples taken from a given lot. Samples should be as widely separated as possible. Easiest to sample this material while being delivered of fed, so a representative sample is obtained. Grain probe will aid in obtaining a good random sample. 3. General A representative sample is as important as the accuracy of analysis in obtaining reliable results. A carefully taken sample the information e when one is mindful of why it is taken, use of the results and cost involved, yields the information needed to improve the feeding program. Feed analysis must be used in designing the feeding program. Properly balancing the protein and energy of the ration can increase profits in three ways: a. If protein is higher than needed then it can be reduced and supplement costs decreased. b. If underfeeding is the problem, then adding additional protein or energy may increase production with only a slight increase in supplemental cost. c. If protein and energy meet requirement, yet production is below expectation, feed analysis can confirm that some other factor is limiting production. Feed analysis also provide information useful in improving feed harvesting program to obtain the highest quality feed for the animal that will yield the most profit to the producer. Questions: Give the best answer. (10 points each) 1. What are the factors to consider in obtaining samples for analysis? 2. Important things to do for the samples to be analyse. 5 LESSON 2 PROXIMATE ANALYSIS Proximate analysis is a combination of analytical procedures developed in Weede, Germany more than a century ago. Different fractions that result from the proximate analysis include water, ash, CP, EE, CF and nitrogen-free extract (NFE). It is the most generally used chemical scheme for describing feedstuffs in spite of the fact that the information it gives often is of uncertain nutritional significance, or may even be misleading. Therefore, consider in some detail the nature, peculiarities and limitations of proximate analysis as a description of the nutritional properties of feedstuffs. Determination by Proximate Analysis a. Dry matter Heat sample to a constant weight at a temperature above the boiling point of water (100 - 105°C). This removes the water, so loss in weight equals water (100% - H2O = D.M. %). Source of error: any materials that volatilize at the temperature are lost (silage, fermented products). Some liquids oxidize when heated and therefore increase in weight. Other method for determination of water in feed includes distillation, drying under vacuum and freeze drying. b. Ash (mineral) Burn samples by placing a weighed amount in a muffle furnace for 2 hours at 600°C. Ash is considered as the dry inorganic residue remaining. The water, fat, protein, CHO have been removed by the process. This high temperature may alter forms of some minerals and even volatilize some like chlorine, Zinc, selenium and iodine. 6 c. Crude protein (Kjeldahl process) Digest small dried sample in concentrated sulphuric acid until all organic matter is destroyed. Nitrogen from feed is now in the form of ammonium sulphate. The digest is neutralized with sodium hydroxide, distilled, driving the ammonia over into standard acid and titrated. This determines the amount of N in the sample. Protein contains an average of 16% N; therefore, total N x 6.25 = CP in the sample. The analysis does not distinguish one form of N from another. Thus, we cannot tell if a feed mixture has true protein (aa) or other NPN sources. In addition, nitrate N is not converted to ammonia salts by this procedure. d. Ether extract (fat) Extract dry sample with ether for a period of 4 hours or more. This removes the fat, so again the loss in weight after drying (evaporation of ether) equals the fat. This process includes as “fat” any ether-soluble compounds including some non-nutrient compounds such as chlorophyll, volatile oils, resins, pigments, plant waxes, which are of little value to animals. e. Carbohydrates (CHO) Not determined by analysis as such, CHO = CF + NFE a. Crude Fiber (CF) After removal of water and ether extract from a sample of feed, the sample is b oiled in weak acid (0.255 N H2SO4), then in weak alkali (0.312 NaOH). This removes the proteins, sugars, starches, which are discarded. Cellulose, lignin and mineral matter are 7 left in the feed residue. This material is dried and weighed, then burned in a muffle furnace at 600°C. Loss in weight is reported as CF. This fraction consists primarily of hemicellulose and some insoluble lignin. b. Nitrogen-free extract (NFE) NFE is found by difference – not by actual analysis. The percentages of water, ash, protein, fiber and fat are merely added together and subtracted form 100. NFE is made up primarily of readily available CHO (sugars, starches, but some hemicellulose, lignin particularly in feedstuffs, forages. Question: (20 points) 1. Illustrate the process in obtaining CP of corn using Kjeldahl process. 8 LESSON 3 VAN SOEST (DETERGENT) METHOD OF FORAGE EVALUATION The proximate analysis system of feed analysis has served for many years and continues to serve a very useful purpose in predicting the nutritive value of feeds. However, there are some definite limitations of this system, especially with respect to both the CF and NFE fractions. The material that was dissolved by the solvents (NFE) was assumed to be digestible and the residue (CF) was assumed to be indigestible. Later studies showed that in some cases CF was more digestible than was NFE. Low digestibility of the NFE fraction arises from the fact that nearly all of the fibrous hemicellulose, variable amount of lignin is dissolved in weak acid and alkali. Both fractions have been shown to relatively indigestible. Van Soest (detergent) Method of Forage Evaluation To develop a chemical procedure that fractionates forages into relatively digestible and indigestible portions, Van Soest proposed the extraction scheme below. The portion of the plant material that is soluble in neutral detergent, cell contents, is virtually completely digested by the ruminant. The residue from this fraction, cell wall constituents, is of low but variable availability depending upon the species of plant and its state of maturity. A similar statement can be made about acid detergent fiber and cellulose. Lignin is nearly indigestible. a. Detergent feed analysis scheme (Figure 1). b. Uses for the Van Soest system. a. Predict intake – NDF is used as an index of gut fill to predict voluntary feed intake. b. Predict digestibility – ADF is used as an indicator of forage digestibility. 9 Figure 1. Detergent feed analysis scheme c. Heat damaged forages – heat damage is caused by ensiling of forages particularly alfalfa, at low moisture levels, allowing air into the ensiled mass. This results in aerobic instead of anaerobic fermentation. During aerobic fermentation, temperature in the silo increases and the forage protein and CHO combine, making the protein unavailable to animals. Other forage or concentrate feeds exposed to heat may also be susceptible to this reaction. The amount of heat damage or decrease in protein availability can be determined by the acid detergent insoluble nitrogen (ADIN) method. This test involves analysis of the forage for ADF, total N, and N in the ADF (both by Kjeldahl). The unavailable or indigestible protein content of feed (ADIN) is subtracted from the total protein content (total N) to determine the amount of protein actually available to the animal. Example: 1) Alfaalfa silage analysis (DM basis): Total N, % = 3.05% ADIN, % = 0.25% 2) 3,05 – 0.25 = 2.80% N available 3) 2.80 divided by 3.05 (100) = 91.8% of the total N (protein) is available to the animal ( or 8.2% is Unavailable) 4) As a general guideline: 10 Unavailable Protein Level of heat damage 0 – 10% None or very slight 11 – 25% Moderate to severe >26% Severe d. Determining net energy (NE) and TDN levels of forage – the following equations can be used to calculate the energy content of forage (all values are on a DM basis): Legumes NEm (Mcal/lb) = 1.1698 – 0.0111 x NDF NEg (Mcal/lb) = 0.9095 – 0.0122 x NDF NEL (Mcal/lb) = 1.0440 – (0.0119 x ADF) TDN (%) = 4.8980 + (NEL x 89.796) Question: (10 points) 1. During wet and dry season, it is advisable to do silage? Yes or No? Justify your answers. 11 LESSON 4 OTHER METHODS FOR FEED ANALYSIS The discovery of near-infrared energy is ascribed to William Herschel in the 19th century, but the first industrial application began in the 1950s. In the first applications, NIRS was used only as an add-on unit to other optical devices that used other wavelengths such as ultraviolet (UV), visible (Vis), or mid-infrared (MIR) spectrometers. In the 1980s, a single-unit, stand-alone NIRS system was made available, but the application of NIRS was focused more on chemical analysis. With the introduction of light-fiber optics in the mid-1980s and the monochromator-detector developments in the early 1990s, NIRS became a more powerful tool for scientific research. Near-infrared spectroscopy is widely applied in agriculture for determining the quality of forages, grains, and grain products, oilseeds, coffee, tea, spices, fruits, vegetables, sugarcane, beverages, fats, and oils, dairy products, eggs, meat, and other agricultural products. It is widely used to quantify the composition of agricultural products because it meets the criteria of being accurate, reliable, rapid, non-destructive, and inexpensive (Burns, 2007). A. NEAR INFRARED REFLECTANCE SPECTROSCOPY Development of near Infrared Reflectance Spectroscopy (NIRS) technology has been a real boom for assessing forage quality. This procedure involves an instrumental method for rapidly and reproducibly measuring the chemical composition of samples with little or no sample preparation. Based on the fact that each of the major chemical components of a sample has near infrared absorption properties that can be used to distinguish one component from the others. In the near infrared range, absorption occur primary as a result of vibrations of light weight atoms that have strong molecular bonds. When there are weak chemical bonds, or heavy atoms, the vibration frequency is low and will not be detected in the near infrared range. Thus, NIR is primarily limited to chemicals bonds containing hydrogen attached to atoms such as nitrogen, carbon or oxygen. Consequently, the detection of minerals is poor unless the mineral exists in association with some organic constituent. NIRS method of analysis has four main advantages over the more traditional wet – Lab Procedures: 1) Speed 2) Simplicity of sample preparation 3) Ability to analyse multiple components in one operation 4) No portion of the sample is consumed by the procedure 12 NIR measurements can be made in less than 1 second. Although typical times range from 30 seconds to 3 minutes, and the only sample preparation usually required is to grind the sample. In contrast, wet-Lab procedures take several hours to perform and require more extensive sample preparation. NIRS has its disadvantages: 1) Requirement of a high precision instrument 2) Dependence on calibration procedures 3) Inability to measure minor constituents NIRS method is still a developing technology. Rapidly gaining popularity in the feed industry because of its speed in obtaining analysis data. When utilized in the field, hay auction, can provide valuable information quickly. As the instrumentation continues to improve, new applications, such as AA analysis and the detection of molds, mycotoxins, may become possible. Figure 2. (a) A system for carrying out NIR spectroscopy. An experimental setup for carrying out near-infrared spectroscopy, here using a transmission cell for liquid samples; (b) Inside an FITR spectrometer. A schematic of a Fourier transform infrared (FTIR) spectrometer for carrying out mid-infrared spectroscopy. The sampling method here is called attenuated total reflectance and can be used for examining liquid and solid samples. B. DETERMINATION OF VITAMINS Because of the diversity of compounds in this class, there is no routine analysis for vitamins. However, methods are available for assaying individual vitamins. Biological assays are used for some vitamins, whereas others are determined strictly on the basis of chemical analysis. 13 C. DETERMINATION OF ENERGY The bomb calorimeter is an instrument used for determining the gross energy content of a material (solid, liquid, or gas). The energy value of the given sample is determined by burning it in an atmosphere of oxygen. When the sample id burned, the heat liberated raises the temperature of water surrounding the container in which the sample is enclosed, and the temperature increased provides the basis for calculating the energy value. The energy value is expressed in units called calories where 1 calorie is the amount of heat required to raise the temperature of 1 g water from 14.5% to 15.5°C. D. THE NUTRIENT OR ENERGY CONTENT OF A FEED MAY BE EXPRESSED AS A PERCENTAGE OR QUALITY PER UNIT OF WEIGHT (mg/kg, g/lb, etc.) ON ONE OF THE FOLLOWING BASIS: 1. Dry matter basis – amount contained in only the dry matter fraction, without water. 2. As-fed basis – amount contained in the feed as it would be fed to the animal, including water. 3. Air-dry basis – generally assumed to be approximately 90% dry matter. Most feeds will equilibrate to about 90% dry matter after prolonged storage (aerobic). Air-dry and as-fed basis may be the same for many common feeds. 4. Since feeds contain varying amounts of dry matter. It would be much simplier and more accurate, if both feed composition and nutrient requirement values were on a dry matter basis. 5. Conversion of feeds nutrients from an as-fed to a dry matter basis. a. Assume alfalfa silage analysed 7% CP on as as-fed basis and contained 40% DM. What percent CP would be alfalfa silage contain when expressed on a DM basis? The Solution for this example can be obtained by the following equation: % nutrient (as-fed basis) = % nutrient (DM basis) % feed DM 100% DM Thus: 7 𝑥 1) x 40 100 2) 40𝑥 = 700 (𝑣𝑎𝑙𝑢𝑒 𝑜𝑏𝑡𝑎𝑖𝑛𝑒𝑑 𝑏𝑦 𝑐𝑟𝑜𝑠𝑠 − 𝑚𝑢𝑙𝑡𝑖𝑝𝑙𝑦𝑖𝑛𝑔 14 700 3) 𝑥 = = 17.5 40 4) The alfalfa silage contains 17.5% CP on a DM basis. b. Two samples of shelled corn were sent to a laboratory for analysis of CP. One sample was dry corn and the other “high-moisture” corn. The laboratory send back the following analysis: Dry corn High moisture corn 89.0 % DM 75.0 8.8 % CP (as-fed basis) 7.4 To compare CP content to the samples, calculate the composition on a DM basis. 1) Dry corn: 8.8 𝑋 1. = 100 89 2. 89X = 880 880 3. X = = 9.88 89 2) High moisture corn: 7.4 𝑋 1) = 75 100 2) 75X =740 740 3) X = = 9.87 75 Thus, the two samples of corn contain the same percent CP expressed on a DM basis. 6. Conversion of feed nutrient from a DM to an as-fed basis. a. Assume a feed nutrient composition table lists linseed meal as containing 10% CF on a DM basis. If the linseed meal contains 91% DM, What is the percent CF expresses on an as-fed basis? The solution for this problem can be obtained by the same equation given in the previous example. x 10 i. = 91 100 ii. 100x = 910 15 910 iii. X= = 9.1 100 iv. The linseed meal contains 9.1% CF on as-fed basis. b. Three samples of corn silage contain the following digestible energy (DM basis) and % DM levels: Sample DE, kcal/kg % DM A 1230 40 B 1225 36 C 1237 33 Calculate DE, kcal/kg, on an as-fed basis. The same equation is followed with nutrient concentration per weight unit (kcal/kg) used rather than percent. 2. Sample A: x 1225 i. = 40 100 ii. 100x = 49,200 49,200 iii. X = = 492 100 3. Sample B: x 1225 i. = 36 100 ii. 100x = 44,100 44,100 iii. X= = 41 100 4. Sample C: x 1237 i. = 33 100 ii. 100x = 40,821 40,821 iii. X= = 408 100 Digestible energy levels to the three samples on an as-fed basis: A = 492 kcal/kg B = 441 kcal/kg C = 408 kcal/kg 16 7. Convert the weight of ration ingredients from an as-fed to a DM basis. Problem: How many kilograms of ration DM are consumed daily if a steer is being fed the following amounts of as-fed feeds? Corn silage 10.0 kg (40% DM) Corn grain 4.0 kg (89% DM) Supplement 0.5 kg (92% DM) Total 14.5 kg As-fed ration The solution is obtained with the following equation: Parts DM feed = Parts as-fed feed x % DM in feed (kg, lb, g, etc.) Thus: Feed Kg, as-fed x %DM = Kg DM Corn silage 10.0 X.40 = 4.00 Corn grain 4.0 X.89 = 3.56 Supplement 0.5 x.92 = 0.46 14.5 8.02 kg 8. Convert the weight of ration ingredients from a DM basis to an as-fed basis. Problem: Following concentrate mixture is being fed to yearling horses. Feeds are presented as pounds of DM. Calculate the pounds of as-fed feeds in this diet. Rolled oats 1045 Cracked corn 425 Soybean meal 182 Molasses (liquid) 80 Dicalcium phosphate 23 Vitamins-mineral premix 10 1765 lb DM The solution for the above example can be obtained with the following equation: Parts (kg, lb, g, etc) as-fed feed = Parts DM feed ÷ % DM in feed. 17 Thus: Feed Lb, DM ÷ %DM = Lb, as-fed Rolled oats 1045 ÷.87 = 1201.1 Cracked corn 425 ÷.90 = 477.5 Soybeam meal 182 ÷.91 = 200.0 Molasses (liquid) 80 ÷.75 = 106.7 Dicalcium phosphate 23 ÷.96 = 24.0 Vitamins-mineral premix 10 ÷ 1.00 = 10.0 1765 2,019.3 9. “Thumb rule” for converting to and from DM and as-fed A. When converting as-fed to DM a. Nutrient concentration will increase b. Weight will decrease B. When converting DM to as-fed. a. Nutrient concentration will decrease b. Weight will increase 10. A chemical or proximate analysis fails to give adequate information regarding digestibility, palatability, toxicity or nutritional adequacy. Thus, further steps need to be taken to evaluate a feed. Questions: (10 points each) Compute the following, show your solution. 1. Napier silage analysed 6.5% CP on as-fed basis and contained 45% DM. What percent CP would be napier silage contain when expressed on a DM basis? 2. Corn silage analysed 8% CP on as-fed basis and contained 55% DM. What percent CP would be corn silage contain when expressed on a DM basis? 18 LESSON 5 FEEDING TRIAL AND DIGESTION OR METABOLISM TRIAL Animal feeding trial experiments are performed to investigate the comparative effects on growth of different diets. The experiments are carried out over several generations of a large number of animals. Digestion trials provide an estimate of the total amount of a specific nutrient absorbed from the gastrointestinal tract. Digestion trials can be performed to measure the digestibility of a range of feed components including the general nutrient class or a specific component within the class. The two measures of digestibility are apparent and true digestibility. Apparent digestibility does not account for endogenous sources and true digestibility does account for endogenous sources of the nutrient of interest. Endogenous materials include intestinal cells, enzymes, and microbes. Apparent digestibilities have limited use for nutrients significantly influenced by endogenous materials. Generally, digestion trials measure apparent digestibility. A digestion trial will have an initial adjustment period followed by a sampling period. A. FEEDING TRIAL A feeding trial simply gives an indication as to whether the animal will accept the feedstuff and the performance obtained from the feedstuff as compared to other. It tells nothing of why different results were obtained. B. DIGESTION OR METABOLISM TRIAL A. Chemical analysis is the starting point determining the nutritive value of feeds. But the actual value of ingested nutrients depends on the use the body can make of them. The first consideration here is digestibility, since undigested nutrients do not get into the body proper. B. A Digestion Trials Consists chiefly of a. Running a proximate analysis of feed. b. Feeding an animal a given amount of feed, or feeding at a constant rate. c. Collecting feces from given amount by use of a marker or collecting feces at a given time on a constant rate feeding. d. Running a proximate analysis of feces e. The difference is the apparent digestible portion of the feed. f. Computed as follows: 19 Nutrient intake −Nutrient in fecee Apparent digestibility (%) = 𝑥 100 Nutrient intake C. Methods Employed for Fecal Collection 1. Marker fed with the ration at beginning and end of the collection period. a. Desirable properties of markers Physiologically inert Contain no element under investigation Will not diffuse b. Types of markers Carmine Ferric oxide Chromic oxide Soot c. Use of markers is not desirable in animals with larger and more complicated digestive tracts (ruminants). d. Using the marker method requires accurate measurement of the total amount of feed. 2. Indicator method – involves the use of an “inert references substances” as an indicator. a. Ideal specifications of indicators Totally indigestible and unabsorbable. Have no pharmacological action on the digestive tract. Pass through the tract at a uniform rate. Are readily a natural constituent of the feed under test. Preferably a natural constituent of the feed under test. b. By determining the ratio of the concentration of the reference substance to that of a given nutrient in the feed and the same ratio in the feces resulting from the feed, the apparent digestibility of the nutrient can be obtained without measuring either the feed intake of feces output. c. The calculation is made as follows: %