lecture 1 (plant and animal compostio-water).pdf

# Introduction to animal nutrition and its importance Nutrition is defined as the interrelated steps by which a living organism assimilates food and uses it for growth, tissue repair and replacement, or elaboration of products. The increasing global demand for meat and other animal products necessitates efficient animal breeding and feeding systems [4](#page=4). ### 1.1 The significance of animal nutrition Improving animal production can be achieved through various means, including increasing the number of animals, genetic selection (heredity), implementing hygienic measures, and optimizing the system of feeding. In both animals and humans, nutrition profoundly influences health and welfare, emotional states, susceptibility to and recovery from diseases, and the incidence and severity of chronic metabolic diseases associated with aging [8](#page=8) [9](#page=9). > **Tip:** Understanding animal nutrition is crucial for enhancing livestock productivity and animal well-being. ### 1.2 Core components of livestock feeding science To master the science of livestock feeding, a comprehensive understanding of several key areas is essential [10](#page=10): 1. **Chemical composition of plants and animals:** Knowledge of the chemical compounds that constitute both feedstuffs (plants) and the animal body itself is fundamental [10](#page=10). 2. **Nutrient requirements:** Identifying the specific nutrients that the animal body requires for its proper functioning and metabolism is critical [10](#page=10). 3. **Digestion, absorption, and utilization of feed:** Understanding the processes of digestion, absorption, and the subsequent use of food by the animal, along with methods to measure feed usefulness, is necessary [10](#page=10). 4. **Body process and productive function nutrient requirements:** Determining the nutrient needs for various physiological processes within the animal body and for productive functions (e.g., milk production, growth) is vital [11](#page=11). 5. **Production problems and care:** Familiarity with common issues in livestock and poultry production, and how feeding and care practices address these challenges, is important [11](#page=11). 6. **Study of specific feeding aspects:** This includes evaluating the nutritive values of feeds, understanding feeding standards, and the practical application of ration formulation [11](#page=11). ### 1.3 Evidence of nutritional advancements in livestock Good nutrition is a cornerstone of effective livestock production, emphasizing the judicious use of available feedstuffs to create palatable, economical, and nutritionally balanced rations for both livestock and poultry. The dramatic improvements in animal productivity over the past fifty years highlight the impact of advancements in animal nutrition [16](#page=16): * **Dairy cows:** Average milk production has risen significantly, with some herds now producing up to 9000 kilograms of milk per year, compared to 1200-1500 kilograms per year fifty years ago [16](#page=16). * **Beef cattle (steers):** Previously, steers took 5-6 years to reach a body weight of 500 kilograms, requiring approximately 15 kilograms of feed for each kilogram of gain. Currently, on high-grain diets, steers can reach the same weight at 12-15 months of age and utilize only 5-6 kilograms of feed per kilogram of gain [16](#page=16). > **Example:** The progression in dairy cow milk yield and the improved feed efficiency in beef cattle demonstrate the tangible benefits of applied animal nutrition research and practice. --- # Major classes and classification of nutrients This topic details the essential classes of nutrients and their classification into macronutrients and micronutrients based on the quantity required by the body. ### 2.1 Major classes of nutrients There are six major classes of nutrients essential for human health. These are [5](#page=5): * Carbohydrates [5](#page=5). * Proteins [5](#page=5). * Fats [5](#page=5). * Vitamins [5](#page=5). * Minerals [5](#page=5). * Water [5](#page=5). ### 2.2 Classification of nutrients Nutrients can be broadly classified into two main categories based on the amount required by the body: macronutrients and micronutrients [6](#page=6). #### 2.2.1 Macronutrients Macronutrients are nutrients that the body needs in relatively large amounts. These include [6](#page=6): * **Water:** Essential for numerous bodily functions, including regulating body temperature, transporting nutrients, and lubricating joints [6](#page=6). * **Carbohydrates:** The body's primary source of energy [6](#page=6). * **Fats:** Provide energy, support cell growth, protect organs, and help absorb certain vitamins [6](#page=6). * **Proteins:** Crucial for building and repairing tissues, producing enzymes and hormones, and supporting immune function [6](#page=6). #### 2.2.2 Micronutrients Micronutrients are nutrients that the body needs in smaller quantities compared to macronutrients. These include [6](#page=6): * **Vitamins:** Organic compounds that play vital roles in various metabolic processes and overall health [6](#page=6). * **Minerals:** Inorganic substances that are essential for a wide range of bodily functions, including bone health, nerve function, and fluid balance [6](#page=6). > **Tip:** Understanding the classification of nutrients helps in planning a balanced diet, ensuring that the body receives adequate amounts of both macronutrients for energy and building blocks, and micronutrients for essential metabolic processes. --- # Composition of plants and animal bodies This section details the principal constituents of living plants, focusing on water, carbohydrates, proteins, lipids, and minerals, and their distribution, before contrasting this with the composition of the animal body, highlighting differences in carbohydrate and fat content, and the typical percentages of water, protein, fat, and minerals in adult mammals. ### 3.1 Plant body composition The primary constituent of living plants is water. This water content tends to decrease as the plant matures and its seeds develop [19](#page=19). #### 3.1.1 Dry matter composition of plants A key difference between plants and animals lies in their dry matter composition. Plants primarily consist of carbohydrates, which serve as both structural and reserve materials [19](#page=19). ##### 3.1.1.1 Proteins in plants Protein is a crucial component, particularly in active tissues like leaves, making them richer in protein than stems. Leafy, legume hays, such as alfalfa and clovers, generally contain more protein than grass hays. As a plant matures, protein moves from the vegetative parts to the seeds to support growth during germination. Consequently, mature seeds exhibit a higher percentage of protein compared to the rest of the plant [20](#page=20). ##### 3.1.1.2 Lipids in plants Lipids are generally found in higher concentrations in leaves than in stems. They are typically most abundant in seeds, where they function as a condensed energy reserve for later germination. While cereal grains like corn store energy primarily as carbohydrates, oil-bearing seeds store their energy reserve mainly as fat. Oil-bearing seeds also tend to be higher in protein than cereal grains [21](#page=21). ##### 3.1.1.3 Mineral matter in plants The mineral content of plants varies significantly depending on the species and the specific plant part. Calcium is predominantly associated with the vegetative portions, with leaves containing more calcium than stems. Seeds are relatively low in calcium compared to other plant parts. In contrast to calcium, phosphorus is found in higher concentrations in seeds than in stems. The soil's composition influences the calcium and phosphorus content of the vegetative parts of the plant [22](#page=22). ### 3.2 Animal body composition In contrast to plants, animal bodies, on a dry matter basis, contain very low concentrations of carbohydrates and generally higher concentrations of fat [32](#page=32). #### 3.2.1 Typical composition of adult mammals An adult mammal typically exhibits the following body composition: * Water: approximately 60% [32](#page=32). * Fat: approximately 20% [32](#page=32). * Protein: approximately 16% [32](#page=32). * Mineral matter: approximately 4% [32](#page=32). * Carbohydrates: approximately 1% [32](#page=32). #### 3.2.2 Variation in animal body composition The gross composition of the animal body, as illustrated by various species, shows some variation in the percentages of water, protein, fat, and mineral matter [33](#page=33). > **Example:** A calf typically has a water content of 74%, protein of 19%, fat of 3%, and mineral matter of 4%. In contrast, a steer that is thin has 64% water, 19% protein, 12% fat, and 5% mineral matter. A horse has 60% water, 18% protein, 18% fat, and 4% mineral matter. A hen has 57% water, 21% protein, 19% fat, and 3% mineral matter. A rabbit has 69% water, 18% protein, 8% fat, and 5% mineral matter. Humans typically have 60% water, 18% protein, 18% fat, and 4% mineral matter [33](#page=33). ##### 3.2.2.1 Water content and organic substances Water content and the proportion of organic substances are subject to significant variations influenced by age, nutritional status, and individual differences. The percentage of water in the body shows a substantial decrease during early life [34](#page=34): * Embryo after conception: approximately 95% [34](#page=34). * At birth: 75-80% [34](#page=34). * At five months: 66-72% [34](#page=34). * Mature animal: 50-60% [34](#page=34). ##### 3.2.2.2 Mineral composition Mineral composition also varies depending on age and the state of fattening. However, the major components of the ash (inorganic residue after combustion) remain relatively constant across different species [35](#page=35). > **Tip:** While species-specific variations exist, understanding the typical ranges and factors influencing composition (like age and nutrition) is crucial for biological and agricultural contexts. ###### 3.2.2.2.1 Major and trace elements in animal bodies The mineral composition of an animal body includes both major elements present in higher percentages and trace elements present in smaller quantities (milligrams per kilogram) [36](#page=36). * **Major elements (%):** * Calcium: 1.5 [36](#page=36). * Phosphorus: 1.0 [36](#page=36). * Sodium: 0.16 [36](#page=36). * Potassium: 0.2 [36](#page=36). * Chlorine: 0.11 [36](#page=36). * Magnesium: 0.04 [36](#page=36). * Sulfur: 0.15 [36](#page=36). * **Trace elements (mg/Kg):** * Iron: 20-80 [36](#page=36). * Zinc: 10-50 [36](#page=36). * Copper: 1-5 [36](#page=36). * Manganese: 0.2-0.5 [36](#page=36). * Iodine: 0.3-0.6 [36](#page=36). * Cobalt: 0.02-0.1 [36](#page=36). * Molybdenum: 1-4 [36](#page=36). * Selenium: 1.7 [36](#page=36). --- # Water: composition, functions, sources, and requirements Water is fundamental to animal life, acting as a critical component in metabolism, temperature regulation, and the structure and lubrication of various bodily tissues. ### 4.1 Body water composition and influence of age and fat * Water constitutes a significant portion of an animal's body mass, ranging from approximately one-half to two-thirds in adult animals [38](#page=38). * In newborn animals, this proportion can be as high as 90% [38](#page=38). * The water content of an animal's body is variable and is influenced by factors such as the age of the animal and the amount of fat present in its tissues [44](#page=44). * Water content is highest in fetuses and newborns, decreasing rapidly in early life and then more slowly as the animal approaches adult levels [44](#page=44). ### 4.2 Functions of water Water is essential for all animal life, performing several critical functions [40](#page=40). #### 4.2.1 Water and body metabolism * Water is a primary constituent of an animal's metabolism [40](#page=40). * Life cannot be sustained without sufficient water, and animals can survive longer without food than without water [38](#page=38). * All biochemical reactions within an animal's body require water [41](#page=41). ##### 4.2.1.1 Water as a solvent * The solvent properties of water are crucial because most protoplasm is a mixture of colloids and crystalloids dissolved in water [41](#page=41). ##### 4.2.1.2 Water as a transport medium * Water facilitates the transport of semisolid digesta within the gastrointestinal tract (GIT) [42](#page=42). * It also serves as a medium for various solutes in blood, tissue fluids, cells, secretions, and excretions like urine and sweat [42](#page=42). ##### 4.2.1.3 Water as a diluent * Water dilutes cell contents and body fluids [42](#page=42). * It aids in transporting absorbed substances to and from sites of metabolism [42](#page=42). ##### 4.2.1.4 Water in hydrolysis and oxidation * Water participates in many chemical reactions, including hydrolysis and oxidation [43](#page=43). #### 4.2.2 Water and body temperature regulation * The physical properties of water are augmented by the physiological characteristics of animals to regulate body temperature [43](#page=43). #### 4.2.3 Water function in the eye, ear, joints, and cerebrospinal fluid (CSF) * Water is integral to the structure of the eye and contributes to the formation of prelymph in the ear and cerebrospinal fluid (CSF) [43](#page=43). * Water also acts as a lubricant for the joints [43](#page=43). ### 4.3 Water sources Water available to animal tissues is derived from three primary sources [45](#page=45): 1. **Drinking water:** This is the most obvious source of water intake. The pH of most drinking water ranges from 6 to 9, which is generally satisfactory for livestock. Water with pH values outside this range is considered unsuitable for livestock [38](#page=38). 2. **Water contained in or on feed:** The moisture content of feed varies significantly, from approximately 5% to 75% in mature plants and hays, and can be 90% or more in lush, young vegetation [45](#page=45). 3. **Metabolic water:** This is generated through the oxidation of organic components within the body's cells [45](#page=45). ### 4.4 Water absorption * Water is readily absorbed from most sections of the gastrointestinal tract [46](#page=46). ### 4.5 Water requirements Water consumption is directly related to heat production, energy consumption, and body surface area [46](#page=46). #### 4.5.1 Factors affecting water requirements ##### 4.5.1.1 Dietary factors * **Dry matter intake:** At moderate temperatures, dry matter intake is highly correlated with water intake [47](#page=47). * **Feed water content:** The inherent water content of the consumed feed significantly influences water intake [47](#page=47). * **Protein level:** An increase in dietary protein level leads to increased water intake due to greater urinary excretion of excess protein as urea [47](#page=47). * **Fat intake:** Higher fat intake also results in increased water consumption [47](#page=47). * **Silages:** Consumption of feeds like silages increases water intake [48](#page=48). * **Salt consumption:** The consumption of common salt (NaCl) or other salts stimulates both water intake and excretion [48](#page=48). ##### 4.5.1.2 Animal factors * **Species:** Different species have varying water requirements; for instance, cattle generally require more water than sheep, and birds typically require less than mammalian species [48](#page=48). * **Age:** Young animals generally have higher water requirements than adult animals [48](#page=48). * **Water conservation ability and activity:** An animal's ability to conserve water and its level of physical activity influence its requirements [49](#page=49). * **Physiological state:** Growth, gestation, and lactation significantly impact an animal's water needs [49](#page=49). ##### 4.5.1.3 Environmental factors * **Temperature:** Higher ambient temperatures lead to increased water consumption [49](#page=49). * **Heat stress and humidity:** Elevated heat stress and high humidity also increase the demand for water [49](#page=49). * **Forage-water distance:** In range animals, the distance between water sources and forage affects drinking frequency and consumption amounts [49](#page=49). #### 4.5.2 Expected water consumption of livestock and poultry | Animal | Liters/animal/day | Liters/kg DM | | :-------------- | :---------------- | :----------- | | Beef cattle | 22-66 | 4.1-5.5 | | Dairy cows | 91-102 | As beef + 0.87 liters/kg milk | | Sheep & goats | 4-15 | 2.5-3.0 | | Horses | 23-68 | 2.0-4.0 | | Chickens | 0.1-0.2 | 2.0-5.0 | | Turkeys | 4.4-6.9 | 2.0-5.0 | ### 4.6 Water losses (excretion) Water is lost from the body through several routes [51](#page=51): * Urine * Feces * Sweat * Respiration (lungs) * Production of milk and eggs #### 4.6.1 Factors affecting water excretion * **Nature of the diet:** Losses through the gut vary with diet composition; a larger portion of undigested material leads to greater fecal water loss [52](#page=52). * **Mineral content of the diet:** The mineral content can influence water excretion [52](#page=52). * **Protein content of the diet:** Dietary protein levels can affect water loss, particularly through urine [52](#page=52). * **Species differences:** Different species exhibit variations in their water excretion patterns [52](#page=52). ### 4.7 Water restriction Water restriction can have severe consequences for animals [53](#page=53). * **Moderate water restriction:** This can lead to decreased feed intake, digestive upset, reduced production, and decreased urine and fecal water excretion [53](#page=53). * **Severe water restriction:** This can result in dehydration and ultimately death [53](#page=53). ### 4.8 Water quality * It is essential to ensure that water supplies are safe for animal use [54](#page=54). * Water should be free from toxic elements such as lead, mercury, and insecticides [54](#page=54). > **Tip:** Understanding the interplay between water intake, environmental conditions, diet, and animal physiology is crucial for maintaining optimal animal health and productivity. Pay close attention to the specific needs of different species and life stages. --- # Importance and uses of animals in agriculture and society Animals hold significant importance in agriculture and society extending far beyond their role in food production, providing essential materials, labor, and contributing to recreational and conservation efforts [12](#page=12). ### 5.1 Conversion of feed into food One of the primary roles of livestock is the efficient conversion of various feed sources into food products for human consumption. Ruminant animals, for example, are crucial in transforming forages that are unsuitable for direct human consumption into edible food [12](#page=12). ### 5.2 Provision of clothing and materials Animals are a vital source of materials for clothing and other products. Livestock yield fibers like wool, and their skins are processed into leather, which is used for a wide array of items including shoes and gloves [12](#page=12). ### 5.3 Valuable by-products Beyond meat, animal carcasses yield numerous valuable by-products essential for various industries. These include blood, bone, skin, fat, intestines, brains, stomachs, and glands [13](#page=13). #### 5.3.1 Industrial applications of by-products Hooves and horns are utilized in the production of glue and gelatin. Inedible fats derived from animals find applications in the manufacturing of waxes, soap, lubricants, and printing ink. Furthermore, extracts from endocrine glands provide critical medicinal compounds such as insulin and cortisone [13](#page=13). ### 5.4 Power and recreation In numerous regions globally, animals remain a primary source of power and transportation. They also contribute to recreational activities, with horseback riding and racing being prominent examples. Livestock shows and fairs also serve as a source of recreation for many individuals [14](#page=14). ### 5.5 Conservation and resource utilization Animals play a role in conservation and resource management primarily through the production of manure [15](#page=15). #### 5.5.1 Manure as fertilizer and fuel Livestock generate substantial quantities of manure, which serves as a fertilizer for a significant portion of farmers worldwide. Animal manure can also be utilized as a fuel source for cooking and heating homes [15](#page=15). #### 5.5.2 Other uses of manure Manure can act as a raw material in methane gas digesters for energy production. There is ongoing research into using animal manure as a feed supplement, though this recycling method is still in its experimental stages [15](#page=15). --- ## Common mistakes to avoid - Review all topics thoroughly before exams - Pay attention to formulas and key definitions - Practice with examples provided in each section - Don't memorize without understanding the underlying concepts

| Term | Definition | |------|------------| | Nutrition | The interrelated steps by which a living organism assimilates food and uses it for growth, tissue repair and replacement, or elaboration of products. | | Macronutrients | Nutrients that are needed in relatively large amounts by the body, such as water, carbohydrates, fats, and proteins. | | Micronutrients | Nutrients that are needed in smaller quantities by the body, such as vitamins and minerals. | | Carbohydrates | Organic compounds, such as sugars, starches, and cellulose, that are a primary source of energy for living organisms. In plants, they serve as both structural and reserve material. | | Lipids | A group of organic compounds that includes fats, oils, and waxes, insoluble in water but soluble in organic solvents. They serve as a condensed reserve of energy. | | Proteins | Complex organic compounds made up of amino acids, essential for building and repairing tissues, and for numerous metabolic processes. In animals, they comprise the structure of soft tissues. | | Minerals | Inorganic elements that are essential for various bodily functions, including bone formation, nerve impulse transmission, and enzyme activity. | | Vitamins | Organic compounds that are essential in small amounts for the normal growth and maintenance of life. They act as coenzymes or participate in metabolic reactions. | | Metabolism | The sum of the chemical processes that occur within a living organism in order to maintain life, including the assimilation of food and the elimination of waste. | | Dry matter | The portion of feed that remains after all the water has been removed. | | Gestation | The state or period of being pregnant; the development of an unborn offspring within the body of a female. | | Lactation | The secretion of milk by the mammary glands; the period during which a female produces milk. | | Hydrolysis | A chemical reaction in which water is used to break down a compound. | | Oxidation | A chemical reaction that involves the loss of electrons from a molecule, atom, or ion. In biological systems, it is often associated with energy production. | | Cerebrospinal fluid (CSF) | A clear, colorless fluid that surrounds the brain and spinal cord, acting as a shock absorber and providing nutrients and waste removal. | | Protoplasm | The living substance of a cell or cell organism, consisting of cytoplasm and nucleus. | | Colloids | A heterogeneous mixture whose dispersed phase particles have an diameter between approximately 1 and 1,000 nanometers. | | Crystalloids | Substances that form true solutions and can pass through a semipermeable membrane, such as salts and sugars. | | GIT | Abbreviation for Gastrointestinal Tract, the series of organs responsible for digesting food and absorbing nutrients. | | Semisolid digesta | Partially digested food material in a semisolid state as it moves through the gastrointestinal tract. | | Na | Chemical symbol for Sodium. | | NaCl | Chemical formula for Sodium Chloride, commonly known as salt. | | Ash | The inorganic residue remaining after the combustion of organic matter. In animal composition, it refers to the mineral content. | | Organic compounds | Chemical compounds that contain carbon, typically bonded to hydrogen, and often to other elements like oxygen, nitrogen, and sulfur. | | Water of oxidation | Water produced during metabolic oxidation of organic compounds within the body's cells. | | Urea | A colorless crystalline compound that is the main nitrogenous byproduct of protein and nucleic acid metabolism in animals, excreted in urine. | | Semen | A reproductive fluid produced by male animals, containing sperm and seminal plasma. | | Lead | A toxic heavy metal. | | Mercury | A toxic heavy metal. | | Insecticides | Pesticides used to kill insects. |