eChapters

A scientific experiment is a planned research to obtain new facts or to confirm or refute the results of previous experiments. Research is usually conducted in a controlled environment to study the effect of one or more variables on observations. The objective of research may be to answer a question, verify a hypothesis, or estimate the effect of an independent variable on a dependent variable. After stating the research problem, we need to outline the methodology (or materials and methods) of the research, which includes developing an experimental design.

Scientific experiments are conducted to study the causal relationships between independent variable(s) and dependent variable(s). The researcher manipulates one or more independent variables and measures their effect on one or more dependent variables. Designing an experiment is planning an experiment. It is a complete sequence of steps taken before experimenting to ensure that appropriate data are obtained to perform a data analysis to get valid inferences about the problem. It must be seen that the data collected are relevant to the problem investigated. E.g., studying the effect of breed, age, feed, etc. on milk output. Here, the objects like breed, age, feed, etc. are called treatments. That is, any specific experimental conditions (like the addition of feed additives, new feed formula, etc.) applied to the experimental units are called treatments. The basic objects on which the experiment is done are called experimental units (E.g., a bird, an insect, an animal). However, the responses in all the experimental units receiving the same treatments may not be similar, due to the inherent differences in the experimental units, called experimental error, caused by extraneous factors.

Chicken’s eggs have been used as a food item by human beings since antiquity. The egg is composed largely of the proteins out of the three most important dietary essentials (proteins, fats and carbohydrates). The egg proteins are highly digestible and remarkably complete, containing the most important essential amino acids. The amino acid profile of egg is similar to the ideal balance of amino acids needed by humans. It also supplies various minerals, some in significant amounts, and contains a range of vitamins. The nutritive excellence of the egg enhances the value of any food in which it is incorporated. Meeting consumer demands is a constant challenge for the poultry industry. Present day consumers desire somewhat distinct products with respect to safety, healthfulness, freshness, taste, color, etc. To remain competent, various companies have developed several designer and specialty eggs which have appeared in supermarkets.

This chapter introduces specialty eggs whose composition, production system or marketing attributes differ from conventional eggs. It examines designer eggs, omega-3 enrichment, vitamin and mineral enrichment, organic egg production, free-range and cage-free systems, and welfare-oriented production. The chapter also addresses labelling, certification, consumer trust and the market prospects of specialty eggs. Particular attention is given to the biological basis and technological limits of nutritional enrichment and to critically evaluating claims concerning nutrition, welfare, safety and environmental benefits.

Isolation of RNA from Rat Liver
(Method of Schmidt and Thannhauser, 1945)
Principle

Most of the RNA (ribouncleic acid) of cells is found in the nucleoli and microsomes.These fractions of cells may be isolated by differential centrifugation of cellular homogenates and thus provide an enriched starting material for RNA extraction. Such methods require high speed  centrifugation. An alternate procedure used in the present method is to disrupt the whole cells by homogenization and isolate the nucleic acid of entire homogenate. This procedure consists of the following sequential steps.

To overcome the limitation of proximate analysis P.J. Van Soest in 1963 developed a method which makes use of the concept that the dry matter of plant origin consists of two principal parts:
    1.    Cell contents 
    2.    Cell wall contents

The method is efficient to take care of the defects in the principle of estimating crude fiber and NFE by proximate analysis. Van Soest has partitioned the carbohydrates into various fractions by a system of analysis using detergents. Cell contents are soluble in neutral detergent includes lipids, sugars, organic acids, starch, soluble proteins, NPN compounds and other water soluble materials, where as cell wall (fiber) is insoluble in neutral detergent but it is soluble in acid detergent includes hemicelluloses, cellulose, lignin, lignified nitrogen compounds, heat damages proteins, keratins and silica. This method of partitioning carbohydrate is essential to be expressed in case of ruminants, due to their capacities for making use of different fractions of crude fibre especially the cellulose and hemicellulose, while the simple stomached animals can rarely do so. 

(Method of Olbrich et al., 1971)

Jones and Ekman (1960) showed that ¹⁴⁴Ce is absorbed to a very small extent in the gut of the ruminant and suggested its use as a marker in digestibility trials. Huston and Ellis (1968) studied the affinity of radioactive cerium for feedstuffs and digesta particles in vitro experiments and found that cerium is rapidly absorbed onto and remained tenaciously bound to  digesta particles. Ellis and Huston (1968) tested radioactive cerium as a particulate flow marker in sheep with favourable results.

Experimental Procedure
Three Holstein bulls weighing 315, 239 and 305 kg and one Holstein steer weighing 327 kg are used. Twice daily, at 9.00 am and 9.00 pm, they are fed 3.4 kg of a balanced ration, meeting NRC requirements for normal growth and maintenance.

Limitation of Weende Method

The partition of carbohydrate into fiber (CF) and nitrogen free extract (NFE) is presumed to represent a separation of less digestible starch and sugars. However, in 20 to 30 percent feeds listed by Morrison, the NFE is less digestible than the CF. This comes about for several reasons, the most important of which is the CF method (successive boiling with dilute sulphuric acid and sodium hydroxide) does not recover all the fiber and large portions of fibrous constituents  are extracted into the NFE. The most  important of these fractions are lignin and hemicellulose are dissolved by both acid and alkali. The basic error of the NFE concept is the assumption that if constituents are soluble they are digestible. Lignin, the rigid component of wood, not only is indigestible but lowers the digestibility of substances with which it is associated.

Another portion of the indigestible part of NFE arises from an artifact in the calculation of faecal NFE, where it is presumed that faecal nitrogen is protein (N x 6.25). Actually, 80-90 percent faecal nitrogen is NPN and is composed of bacterial residue in which the ratio of organic matter to nitrogen is about 1:4. Thus, part of the faecal NFE arises by an underestimation of the organic matter associated with faecal nitrogen.

(Method of Bryant et al., 1959)

Strontium and barium are adsorbed on a cation-resin column, and  after a suitable gowth period, yttrium-90, the daughter of strontium-90, is selectively eluted. The yttrium-90 is then adsorbed on and eluted from a second cation-resin column and counted. The radiochemical yield is greater than 97% gravimetric measurement of the recovery of strontium and yttrium carriers is not required. The method, with modifications, is applicable to samples that contain 100 mg of iron or uranium.

Extension worker play a important role in rabbit keeping. It increases food production and experience in rabbit farming, people has to be educated as they have no knowledge of rabbit keeping especially people of towns and villages.

These have to be told the advantages of rabbitry. It is difficult to convince villagers, so extension is very important.

Rabbit Census : Recently taken up.

In Karnataka, census was taken in 1990. There were 16,327 animals.

Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia due to impaired insulin production, insulin resistance or both. It affects various animal species, including dogs, cats, horses and occasionally other animals like birds and ferrets. This condition requires lifelong management and, if left untreated, can lead to severe complications such as ketoacidosis, neuropathy and organ damage. Understanding diabetes mellitus in animals, its clinical manifestations and appropriate management strategies is essential for improving the quality of life for affected animals.
Types of diabetes mellitus in Animals
There are two primary types of diabetes in animals, analogous to human
diabetes:
1. Type 1 diabetes (Insulin-dependent):
Most common in dogs,
Characterized by the destruction of pancreatic beta cells, leading to insufficient insulin production,
Typically immune-mediated or idiopathic,

The Central Nervous System not only consists of the Brain but also involves the Spinal cord.

The spinal cord is responsible for conveying information from the Brain to the rest of the body via the peripheral nervous system. The spinal cord can be divided into 4 functional segments.

1. C1-C5 (Upper Cervical Segments)

2. C6-T2 (Brachial Plexus)

3. T3-L3 (Thoraco - Lumbar)

4. L4-S3 (Lumbo-Sacral Plexus )

It is important to note that the motor and sensory function of the pelvic limbs are not only controlled by the Lumbo-Sacral plexus but also involve the Thoraco Lumbar segments (T3-L3) of the spinal cord. It is important to understand not only the neuroanatomy, but also the functional anatomy before approaching a neurological patient.

Any abnormal condition, which affects the normal functioning of cells, tissues, organs and any other system in an individual, is called a disease. In all living organisms, including plants, animals, birds and humans, diseases can be caused due to infectious or non-infectious agents and various other factors. Laboratory tests may identify organisms directly (eg, visually, using a microscope, growing the organism in culture) or indirectly (eg, identifying antibodies to the organism). Some tests (eg, Gram stain, routine aerobic culture) can detect a large variety of pathogens and are commonly done for many suspected infectious illnesses. However, because some pathogens are missed on these tests, clinicians must be aware of the limitations of each test for each suspected pathogen. In such cases, clinicians should request tests specific for the suspected pathogen (eg, special stains or culture media or advise the laboratory of the suspected organism(s) so that it may select more specific tests. The main causative factors of diseases in humans include internal factors, genetic irregularities, allergies, poor immune system, external factors and a lot more.

All animals have a range of ambient environmental temperatures termed as thermo-neutral zone. This is the range of temperatures that are conducive to health, performance and well-being. The upper critical temperature is the point at which heat stress begins to affect the animal adversely. There are a number of climatic factors like temperature, humidity, wind speed and radiant energy/sunlight that influence the degree of heat stress. Heat is also produced by metabolism within the body, which includes maintenance, growth and production. Heat production is affected by body weight, species and breed, level of production, level of feed intake, feed quality and, to a lesser extent, by the amount of activity and exercise. Excluding temperature of the air ventilating the house, heat is also added from the roof and walls. Heat stress can be defined as the point where the animal cannot dissipate adequate quantity of heat to maintain body thermal balance. During the periods of heat stress, most of the productive energy is diverted to thermoregulatory adaptations that results into decreased weight gain, poor immunity, oxidative stress predisposing animals to various infectious diseases and high mortality rates. In order to characterize and quantify thermal comfort zones according to animal species, several thermal comfort indices or heat stress indices were developed.

The primary focus for livestock and poultry has been on heat stress indices to provide guidelines for environmental management and risk assessment for losses through linkages with physiological responses (Eigenberg et al., 2005) or performance (Baccari, 2001). The linkage is based on observations of a selected performance criterion (e.g., growth, milk or egg production) made concurrently with measures of the warm environment. These serve as inputs for the selected heat stress index and thus an empirical relationship can be developed which is termed as ?biological response function?. These indices recognize the ability of the animal to cope with environmental stressors by adjusting physiologically, behaviourally and immunologically to minimize adverse effects or even compensate for reduced growth and production performance during moderate environmental challenges. When the intensity and duration of potential stressors exceed thresholds, coupled with limited opportunity for recovery, animals are unable to cope and therefore are affected adversely. Nevertheless, the heat stress indices have served as useful surrogates for the complex interactions between the physical and biological components (Hahn et al., 2003).

Poultry rearing systems vary in scale and complexity, each suited to different production needs and environments. This chapter explores the main poultry housing systems, detailing their advantages and disadvantages to help in selecting the most appropriate method for various farming scenarios.

Housing Systems of Poultry

Generally, there are four types of housing systems in poultry, they are

1. Free range or extensive system,

2. Semi-intensive system,

3. Folding unit system and

4. Intensive system.

One of the major constraints in the efforts to modernize and efficient restructuring of the animal husbandry practices is the delay in taking the results of research to the farming community and in persuading them to adopt new, profitable and locally relevant technologies. The very need of the extension work is to bridge the gap between what is known to the scientists in the laboratories and what is actually being practiced by the farmers in the field. In other words, the major goal of extension machinery is to accelerate the processes of communication and to motivate rural people or livestock owners for adoption of new and profitable technologies. Hence, it is very important to understand these processes of how the farmers get such technologies and how they adopt them.

Communication

The term communication is originated from the Latin word ‘Communis’, meaning common or establishing commoness. When we communicate, we attempt to establish ‘commonality’ with someone through the message.

Communication is the process by which two or more people exchange ideas, facts, feelings or impressions in ways that each gains a common understanding of the meaning, intent and use of the message (Paul Leagens, 1961).

Thousands andthousands ofsamples ofvarious feeds andfoddersweresubjected to Weende analysis fortheir chemical composition have been depictedin various manuals. Such proximate principles of these feeds provide only the potential value forreference or consultationpurpose, but not theactualvalue of feedstuffs. Losses of nutrientsinfaeces(solids), urine (liquid), gasesetc.duringthe digestion, absorption andmetabolismof theanimal shouldalso be taken into consideration. Therefore, a need arises to conduct digestibilitytrial or experiment for the feeds in the ruminant animals. Major portion of the nutrients present in the feeds are not properly digested in the gastrointestinal tract (G.I.T.), hence not completely available to the animal body. Digestibility is that portion of a feed or any single nutrient of feed, which is not excreted in the faeces or dung and it is therefore, assumed to be absorbed by the animal. When this digestibility is expressed in percentage, it is termed as ‘digestibility coefficient (D.C.)’.

Introduction

Digestion may be defined as the hydrolytic process carried out by various enzymes for breaking down complex food components such as proteins, fats and carbohydrates into simpler molecules like amino acids, fatty acids and monosaccharides, respectively. Whereas, absorption may be defined as the movement ofthese simple soluble digested food componentsalongwithvitamins, minerals and water from gastrointestinal track into the circulatory system.

The process of digestion starts from oral cavity (mouth) and ends at large intestineincluding tongue, teeth, jaws,secretions from salivaryglands (parotids, sub maxillary or submandibular and sublingual glands), pharynx, esophagus, stomach, small intestine and digestive enzymes secreted from pancreas and liver.

The history of digestion experiments dates back to the mid-19th century when the first true trials were carried out at the Weende Experiment Station in Germany. In 1858, researchers Henneberg and Stohmann began their experiments and published their findings in 1860, which condemned Thaer’s hay equivalents and gave results of their experiments. These trials coincided with the chemical analysis of feedstuffs at the Weende station. Even before 1860, studies on nutrient losses in feces had been conducted to calculate TDN (total digestible nutrients). Over time, numerous publications have recorded the results of digestion experiments, with Schneider and Flatt (1975) documenting more than 3000 studies. In India, over 430 digestion trials have been conducted with Indian feeds and fodders at various research stations, as published by ICAR. The wealth of information gathered from these experiments has greatly advanced our understanding of digestion processes and has enabled improvements in animal nutrition practices.
Digestibility
Nutrients in feed are not fully utilized by livestock, with a significant portion being excreted in feces due to incomplete digestion in the digestive tract. Digestibility can be defined as the proportion of nutrients that are absorbed by the animal’s body and not excreted. It is essential for the animal’s growth, reproduction, and overall metabolism. Animals fed highly digestible feed show improved growth and reproductive performance, leading to increased market availability.
The formula for calculating digestibility is simply the difference between nutrients in the nutrient consumed and nutrients found in faeces.
Digestibility = Nutrients in forage – Nutrient in faeces

Mixture of nutrientscomprisingcarbohydrates, fats, proteins, minerals, vitamins and water are feed stuffs. From the intestinal wall, very few of such nutrients can pass directly to the body tissues, therefore they must be degraded down into simple compounds before they pass through the mucous membrane of the gastrointestinal tract (G.I.T.) intothe bloodand lymph. This degradation process is regarded as ‘digestion’. Thereafter, the movement of these simple compounds through the mucous membrane oftheG.I.Tract into the blood iscalled absorption. Metabolism is the utilization of these nutrients by the animal body and then excretion of the end products takes place from the body. The digestion of feeds is carried out by three means namely, mechanical action: mastication in the mouth and the muscular contraction of G.I.Tract; chemical action: this is carried out by enzymes secreted by digestive juices and microbial action: this is also enzymatic action, but the enzymes are secreted by microbes instead of host.

In ruminants, it is the rumen which harbours bacteria, protozoa and fungi (Fig. 1) ; whereas in non-ruminants, it is the large intestine (Fig. 2). There are four compartments in the stomach-reticulum, omasum, rumenand abomasums. Reticulumprovides ruminantadditionalspacefor storage.Also, if byanychance, foreign bodies like nails, wires etc. reach over here alongwith feed, they are retained for longer periods and thus, soft organs are protected. Omasum squeezes out water from the feed with the help of its strong muscular walls. In the suckling calves or lambs, the two compartments-rumen and its continuation reticulum are less developed and both are joined by a tube like structure -oesophageal or reticular groove, which directly opens into abomasum. That is why in these sucklings, milk reaches straight into the abomasum, which is the true stomach. Rumen develops at about six weeks of age in these young ones. As these sucklings begin to eat solid feed, both rumen and reticulum enlarge greatly and separate. Now oesophageal or reticular groove does not exist.

Digital dairy farming integrates IoT, artificial intelligence, machine learning, big-data analytics, cloud computing, sensors and automation to improve herd management. This chapter explains how wearable devices and monitoring systems support early disease detection, welfare assessment, milk-yield analysis and precision feeding. Automated milking, feeding and other operations reduce manual labour, improve consistency and lower operating costs. The architecture of smart dairy systems—including sensors, wireless communication and decision algorithms—is examined alongside environmental and economic benefits. Barriers include high initial investment, limited digital skills, poor rural connectivity and cybersecurity risks. Future developments may include AI-enabled autonomous dairy farms and interconnected, sustainable agricultural ecosystems.