eChapters

Introduction

Nutrition, a basic human need, is a critical part of health and development. Nutrition can be defined as the intake of food, deliberated in relation to the body’s dietary needs. On one hand, good nutrition – an adequate, well balanced diet combined with regular physical activity – is a foundation of good health, whereas,poor nutritionleads toreducedproductivity,impairedmental andphysical development, increased susceptibility to disease, and reducedimmunity. According to WHO, under-nutrition, together with vitamin and mineral deficiencies accounts for one-third of all child deaths and impairs healthy development and lifelong productivity. At the same time, sedentary lifestyles, demographic shifts, urbanization and the liberalization of markets have steered the world population to being overweight along with risk of chronic diseases like hypertension, dyslipidemia, type 2 diabetes, coronaryheart disease, stroke, etc.; thus, resulting in a double burden of malnutrition.

To address this dual burden of malnutrition, individuals needaccess to sufficient and good quality food; but focussing solely on food security is unlikely to solve the problem of global malnutrition. The challenges of malnutrition cannot be solvedjustbyincreasingfoodproductioninordertoimprove healthand nutritional status of the population. To resolve such challenges, awareness about food choices for optimal health plays a pivotal role among population.

Human nutrition is the science of understanding food; its component; intake; and how it is related to health, growth, development and diseases. Human nutrition involves the study of ingestion, digestion, absorption and assimilation of the nutrients; their metabolic functions, deficiency or excess disease as well as their regulation through several factors such as choosing particular food components/nutraceuticals or physical activity.

Introduction

The basic physiological structures of mammary glands in all species are almost same and are located externally in order to fulfill the milk requirement of neonates after parturition. The process of secretion of milk from the mammary glands is known as lacto genesis. Milk provides an almost complete nutrition to neonates from birth till weaning period. It is a complex mixture of various constituents like:

Lipids such a striacyl glycerols(TAG),phospholipids,cholesterols and other sterols, free fatty acids and fat-soluble vitamins

Carbohydrates such as lactose, oligosaccharides

Proteins such a scaseins, α-lactalbumin, β-lactoglobulin, immunoglobulin’s, bovine serum albumin, lactoferrin, lysozyme, enzymes, hormones and growth factors

Non-protein nitrogenous compounds like urea, creatine, creatinine, uric acid and amino acids

Major and minor minerals, water-soluble vitamins and cells (leucocytes, macrophages, and epithelial cells).

Introduction

Proteins are the most abundant organic compounds constituting major part of the body. Chemically, proteins are nitrogen containing macromolecules and polymers of L α-amino acids, which serve a wide range of structural and biological functions in animal body. For example, connective tissue made up of collagen, metabolicenzymes, neuro transmitters,signal in gmolecules, structural components of cell membranes and cell organelles, etc. all are chemically proteins.

Before goinginto the details of protein metabolism, first, we need to understand that there are majorly two sources of proteins in our body: dietary protein and body protein. Dietary protein is taken in diet, while body protein indicates the protein and amino acids synthesized in animal body to fulfill the requirements for growth and development. The digestion of proteins will not be discussed here as it has been described in detail in chapter 12. Dietary protein is digested in presence of several enzymes such as trypsin, pepsin, chymotrypsin, aminopeptidases and carboxypeptidases and is converted into mono-, di- and oligopeptides in stomach and small intestine; and finally converted into amino acids. These amino acids are transported to the systemthrough intestinal mucosa via active transport, from where they enter into the cells for further metabolism. Therefore, ‘metabolismof proteins’ is more appropriatelylearnt as ‘metabolism of amino acids’.

Introduction

The diverse cluster of naturally occurring organic compounds including fats, oils, fatty acids, waxes, phospholipids, eicosanoids, terpenes, steroids and fat soluble vitamins that do not prefer to interact with water but soluble in non-polar organic solvents like ether, chloroform, benzene, acetone, are called as lipids. The main functions of lipids in biological system include storage and transport of metabolic fuel, structural component of cell membranes, insulation & protection of vital organs from shock and carrier of fat soluble vitamins. Contradictory to proteins,lipids are not polymers in nature and are hydrophobic due to presence of a long hydrophobic chain. Apart from this, lipids also act as precursor molecules for several pigments, hormones and signaling molecules.

Introduction

Carbohydrates are the most common source of energy for all living cells, which, in presence of light, are formed by the green plants from CO₂ and water during photosynthesis. It canbe said that ‘light’ is theultimatesourceof energyrequired for all livingcells.Glucose,a monosaccharide,plays a centralroleincarbohydrate metabolismin all plants, animals and manymicroorganisms. Glucose is derived from the polysaccharides (starch, glycogen) and non-carbohydrate sources (amino acids, glycerols, etc.) during metabolism and ultimately converted either into carbondioxide and water orotherintermediateproducts.Complete oxidation of glucose to CO₂ and water provides ~2,840 kJ/mol energy. The other monosaccharides such as fructose, galactose, mannose, etc. are also important molecules in carbohydrate metabolism.

Introduction

Hormones may be defined as specific chemical molecules produced in certain specific organs called specialized cells or endocrine glands. They are delivered into the blood stream or some other body fluid in minute amounts by the circulatory system of the body and their they exerts a physiological effect at a site of action remote from its origin, regulating numerous biological activities including growth, development, reproduction, water & electrolyte balance, storage & usage of energy etc.

Introduction

The basic components of diet include carbohydrate, protein, fat, vitamins and minerals. Vitamins are the essential nutrients which are not formed in our body and required in minute amount from the diet. Vitamins are crucial for the optimal functions of several enzymes; thus important for optimal growth and development. Vitamins perform various functions that help in regulation of metabolism, prevent chronic diseases, maintain natural appetite, mental health and immunity.

In 1912, Polish biochemist Kazimierz Funk coined the term ‘vitamine’;a substance that was present in rice polishing and foods that cured polyneuritis in birds and beriberi in humans. The name is from ‘vit’ for vital nutrient and ‘amine’ for its similarity as an amine. Vital signify that these factors are indispensable for life. Earlier they are identified and thought to contain amino groups, thus the word amine was used, which was true for thiamine but later work revealed that most of the vitamins do not have amino groups. Thus the word was shortened to vitamin in English. It should be noted that the term vitamin does not denote to some othern utrients such as essential amino acids, essential fatty acids, dietary minerals or other nutrients that contribute towards good health.

Vitamins may be defined as organic compound needed in minute amount through diet to perform specific biological functions for normal growth and health of the organisms.Vitamins should have following characteristics:

Introduction

The nucleic acids are the molecular depots that are responsible for continuity of life by transfer of hereditary information from one generation to next. The sequence of nitrogenous bases containing programmed instruction determines the structure of every cell constituent and eventually every protein. In 1869, Friedrich Miescher, Swiss chemist, isolated an unknown phosphate-rich substance from pus cells named as nuclein, which was quite different from other organic substances like carbohydrate, protein, and fat. Altmann in 1899 ascertained that the nuclein also had some acidic characteristics and changed its name to ‘nucleic acid’. Later, nucleic acid was also isolated from salmon sperm nuclei as DNA-protaminecomplex. In 1953, James D.Watson and Francis H.C. Crick constructed the model of three-dimensional double helix structure of the DNA molecule which could successfully explain DNA replication.

Introduction

Billions of chemical reactions are happening inside human body and that too with lightning speed. However, the same reactions if carried out in laboratory, they take a very long time. The reasons behind it are the biocatalysts, also known as enzymes, which are synthesized by living cells. Chemically, they are proteins(except ribonucleic acids: RNA), colloidal in nature, thermo-labile in character and very specific in their action. For example, hydrolysis of proteins by a strong acid at 100°C takes a couple of days; but same proteins can be digested within couple of hours inside human body at 37°C. Similarly, carbonic anhydrase is used as a catalyst by living cells to transfer carbon-di-oxide from cells to blood. This process is 107 times quicker than the same process if occurs without the help of enzymes. Therefore, enzymes can be defined as the biomolecules or biocatalysts which can speed up the rate of the chemical reactions. The substance upon which an enzyme acts is called as substrate and the one which is produced as the result of enzyme-substrate reaction is known as product.

Egg Formation Phenomenon

The chicken egg consists of a very small Reproductive cell or Germinal disc [orBlastoderm;which iscapable of developingintoanEmbryo, iffertilized by a Sperm]. This tiny cell is surrounded by :

• Yolk
= OVARYis responsible for its synthesis.

• Albumen, Shell membranes, Shell and Cuticle
= These are produced in the OVIDUCT.

[A] OVARY

Although there are two ovaries and two oviducts in the hen, but only the left ovary and left oviduct are functional [because, the right ones are atrophied during embryo development]. Before egg production, the ovary is a group of small follicles of different sizes containing ova.

Formation of Yolk

• The yolk is just a source of food material for the small Reproductive cell (Blastoderm).

• Major amounts of yolk material is produced in the liver and transported to ovarythrough blood.

• Two days afterthe formationof First yolk. Second yolkbegins to develop.

• It takes about ten days for a yolk to mature.

For economical ration -preparation, selection of cheap feed amongthe locally available sources, is an important point to ponder. For this purpose, a list of available feeds is prepared alongwith their latest costs on dry matter basis. The cost per kgof dry matter is divided by the amount of the nutrient (as a decimal), it will give us a good idea of the :

• Cost of Crude Protein in ??Protein supplements and,

• Cost of Energy in ??Energy feeds.

For example, if alpha alpha hay costs Rs 3.93 per kgof dry matter, the cost per kg of Crude Protein = 3.93/0.171 = Rs 22.98 per kg.

In this way, it is possible to prepare a list of protein sources in the order of “Ranking” from which feeds can be selected at lower costs.

Effect of Differences in Dry Matter

Feeds are purchased on the basis of Dry Matter due to variation of moisture content. For example :

A Corn of 89 % Dry Matter costs Rs 7 per kg,

Another type of corn of 75 % Dry Matter can’t be comparable on this cost This can be done as following 

Chemistry of Alkanes

In living plants, hydrocarbons are universally distributed in the waxy coatings on leaves and other plant organs. Alkane fraction is commonly a mixture of hydrocarbons of similar properties. The qualitative pattern is relatively similar from plant to plant, but there are considerable quantitative variation. Alkanes are saturated long chain hydrocarbons. They are usually present in the range of C to C carbon atoms. Examples are n-nonacosane, C H and n-hentriacontane, C C . In general, odd-numbered carbon chains occur predominantly in the cuticular wax of plants and are substantially indigestible.

How alkanes are “user friendly” !

Following are some points to ponder :

• Alkanes are long carbon chains found naturally in plants and each plant species has its unique compliment of these different alkanes which act like “fingerprints”. Forage intake can be estimated from ‘faecal grab samples’, if the ratio between these endogenous plant alkanes and exogenous alkanes delivered from “a rumen slow - release gelatin capsule” is calculated.

• Alkanes can also be used for determiningdigestibility and characterizing thespecies compositionof thediet, makingalkanes an extremelypowerful tool for dairy research.

• Anenexpensive, reliable and simpletechnique offers tremendous potential for research in the area of low cost dairy production from forages. Such data may be used by “slow–release marker” to estimate intake and digestibility.

• Alkanes offer a potentially simple technique for the animal scientist and it is feasible to estimate alkane concentrations using Near Infra-Red scanning [N.I.R.]. It is a rapid analytical method, thus making alkane technology an extremely ‘user friendly’ tool to be widely adopted on behalf of the dairy industry.

Historical Aspect

The primitive man during his long history as a hunter and food gatherer, used ruminants as food till about 6000 B.C. Later, he developed the arts of aerable -agriculture and animal husbandry. The ruminants played a major role as sources ofbothfoodandmechanicalwork. In turn, the new techniquesof foodproduction greatlyincreased the amount of food available and enabledthe establishment of settled communities.Theradicalnatureof thesedevelopments was clearlyshown by the fact that within a couple of millennia, manhad evolved from primitive to urbanized, civilized communities. Throughout the historical epochs, animal food - meat, milk and milk products continued to form an important fraction of the diet in most of the civilized societies. The favoured nature of these foods was well shown in the observation that, with increasing affluence, human -beings tended to increase the fraction of the diet provided by animal foods, especiallyfromruminants.

Since middle of twentieth century, evidences had been accumulating to indicate that the high intake of saturated fats from meat and ‘dairy products might play a role in the etiology of atherosclerosis. This concern had provided a stimulus to produce husbandrytechniquesleadingto the modification of the composition of ruminant fats as well as possibility of protecting dietary poly - unsaturated fatty acids (PUFA) from ruminal biohydrogenation in 1951. Scientists all the world round, started studying ruiminant fats and ruminal lipid metabolism in this perspective. Different research groups developed various techniques of protectingdietary- PUFA, so as to make themavailable in the meat, milk and its products, but lacked the availability of sensitive techniques for confirmation. With the discovery of Gas Chromatoaraphy (GC) in 1954, a new beginning of resolution and detection of PUFA started with gradual precision. Later on, the GC was further equipped with mass - spectroscopy and subsequently with infra -red detector. The scientists were very much successful in protecting the dietary essential fatty acids (E.F.A.s) or even by - passing them from biohydrogenation in vitro.

The Codex alimentarius is a collection of standards, codes of practice, guidelines and other recommendations relative to food.

It is derived from latin word which means Food Code.

Codex alimentarius is about safe, good food for everyone - everywhere.

International food trade has existed for thousands of years but until not too long agofood wasmainlyproduced, soldand consumed locally. Over the last century theamount offoodtraded internationallyhas grownexponentially, and a quantity and variety of food never before possible travels the globe today.

The CODEX ALIMENTARIUS international food standards, guidelines and codes of practice contribute to thesafety, qualityandfairnessof this international food trade. Consumers can trust the safety and quality of the food products theybuyand importers can trust that the food theyordered will be in accordance with their specifications.

Public concerns about food safety issues are often placing Codex at the centre of global debates. Biotechnology, pesticides, food additives and contaminants are some of the issues discussed in Codex meetings. Codex standards are based on the best available science assisted by independent international risk assessment bodies or ad-hoc consultations organized by FAO and WHO.

Introduction

• Objective of animal diet formulations to provide a palatable ration at minimumcost to meet nutritional and energyrequirements of the animal.

• To achieve this objective, it is important to have knowledge about the requirementsof specific nutrient ingredients and the nutrient composition of feeds, which are used to formulate the animal diet.

• Diet formulation is an important aspect to meet production and financial goals in the most economical way.

• A dietis called balanced if it providesenergyto meet lactation, production and specific level of health requirement.

• Economic as well as nutritional aspects should be considered while optimisingnutrient ingredients.

• These three factors are so intimately related to each other that cannot be separated during the process of feed formulation.

Preliminary Stages

• The first step in diet formulation is to define the objective of diet formulation. Depending on the objective of diet formulation (such as reproduction, lactation, live-stocketc.), requirementsfor nutrient ingredients are established

• This step includes individual units and overall requirement for diet ingredients. After defining the objective of study and diet formulation, requirements of nutrient intake are defined to achieve that objective

• While definingtherequirement, socialenvironment, internal, external and economical conditions should be taken into consideration.Nutrient requirements can be established by the empirical method and factorial method.

• The empiricalmethodisbasedonexperimental studies whereas the factorial method identifies the various functions within the animal that defines the needs of nutrient ingredients.

Introduction

First feed mill was established in 1875 A.D. in the state of Illinois, U.S.A. for calf meal production.

First feed mill in India was established in Ludhiana, Punjab in 1969 A.D.

A mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such communition is an important unit operation in many processes. There are manydifferent types of mills and manytypes of materials processed in them. Historically, mills were powered by hand (e.g., via hand cranks) working animals (horsemill), wind (wind mill) or water (watermill). Today they are usually powered by electricity and are controlled by computer (automatic mills).

The grinding of solid matters occurs under exposure of mechanical forces that trench the structure by overcoming of the interior bonding forces. After the grinding, thestate ofthesolid is changed:thegrain size, thegrain size disposition and the grain shape.

Milling also refers to the process of breaking down, separating, sizing, or classifyingaggregatematerial. For instance rock crushingor grindingto produce uniform aggregate size for construction purposes, or separation of rock, soil or aggregatematerialforthe purposesofstructural fillor land reclamationactivities. Aggregate milling processes are also used to remove or separate contamination or moisture from aggregate or soil and to produce “dry fills” prior to transport or structuralfilling.

Grinding may serve the following purposes in engineering: • Increase of the surface area of a solid

• Manufacturing of a solid with a desired grain size

This procedure allows us to mix two feed stuffs with different nutrient concentrations and come up with a mixture of the desired total concentration. For this square to work, the desired diet nutrient concentration must be between the nutrient concentrations of the two feed stuffs as well as in the same unit. The procedure can be used for Crude Protein, Energy, Minerals and so on and so forth.Also, in place of percentage, calories, parts per million/ billion / trillion and other units of measurement can be used.

Double Pearson Square Method

Sometimes, we might want to have the exact amounts of two major nutrients such as - Crude Protein and Energy.

For example, suppose we want a final mixture with 12 % Crude Protein (CP) and 74 % Total Digestible Nutrient (T.D.N.). We have :

A premixisa mixtureofvitamins, trace minerals, medicaments, feedsupplements and diluents either individually or in a combination. It is a value added solution for feeds with sustainable safety and quality.

The main objective of premixes is to deliver the micro-ingredients in a manner desired by customer. These blends of Micro-ingredients need to be carefully selected, analysed and homogenously manufactured in controlled conditions.

Good quality premixes are manufactured as per following four fundamental principles that determine premix quality and performance :

1. Understanding the chemical and physical attributes in the microingredient to be incorporated.

2. Testing to ensure that all microingredients meet specifications.

3. Controllingthe inclusionin fullproof and secure method.

4. Blending together in speciality mixers to achieve a homogenous mix.

Gas Chromatography (GC) was discovered in 1954, a verysensitive technique, whichpavedwaytothisworldfor the resolution ofthe sampleleadingtodetection … identification of the minutest quantity of the desired sample.

Fattyacids were usuallyconverted into correspondingmethyl esters (FAME) to improve volatility and to reduce peak tailing for GC. Usually, FAME could be conveniently prepared by heating lipids with a large excess of either acid- or base-catalyzed reagents. Whereas, acid-catalyzed reagents form FAME from both free fatty acids (FFA) and O-acyl lipids base-catalyzed reagents caused only transesterification, i.e. conversion of O-acyl lipids to FAME and do not usually form FAME from FFAs. A base-catalyzed reaction was a useful alternative to acid-catalyzedreactions whena lipid sample contained acid-labile FAs such as propenoids, present in seed oils from the Malvales order, such as cottonseedoil. To effect solublizationof nonpolarlipids such as triacylglycerols in methanol. the predominant solvent in derivatization reagents, benzene was frequentlyadded to the derivatizalion reaction mixture. However, due to health concerns, use of benzene was discouraged. To help solubilize nonpolar lipids, methylene chloride and tetrahydrofuran had been used in place of benzene.