eChapters

Endotracheal intubation is the placement of a tube in the trachea to provide a patent airway.

It is a valuable technique that enables to attach an animal to a breathing circuit or, just as importantly, to secure an airway during an emergency such as respiratory or cardiac arrest.

It is important that time be taken to learn the anatomy of the laryngeal area and the skill of intubation so that intubation may be performed quickly and with little chance of misplacement.

These are the drugs that reversibly block the propagation of action potentials along nerve axons. General anesthesia may be advantageous where complete immobilization and relaxation of the patients required. However, local anesthetic techniques are advantageous for providing surgical anesthesia in animals that are considered at risk for inhalant or intravenous anesthesia. These drugs are injected directly at the target site.

Introduction
Experimental physiology is a fundamental aspect of medical, veterinary and biological sciences that seeks to understand how living systems function through controlled experiments. It plays a crucial role in exploring the mechanisms behind normal and abnormal physiological processes. With roots in ancient medicine, experimental physiology was notably advanced by Claude Bernard in the 19th century, who introduced key concepts
like homeostasis and experimental methods that are still in use today. The interdisciplinary nature of this field connects it with disciplines such as biochemistry, pharmacology, and bioengineering, promoting a more comprehensive understanding of biological processes.
Investigating Physiological Processes
Experimental physiology aims to explore how organisms function at the cellular, molecular, organ, and systemic levels. This field investigates both normal physiology and the mechanisms behind diseases, offering insights into how organs and systems interact. Laboratory-based experiments are central to this learning process, allowing students and researchers to apply theoretical knowledge to practical scenarios. By observing how
tissues, organs, and entire systems respond to stimuli, experimental physiology enables the exploration of the relationship between structure and function in biological organisms. The practical experience gained in the lab is critical for medical and veterinary education, as theoretical knowledge alone is insufficient. In fields like physics and chemistry, materials can often be stored for future use. However, in biology, especially physiology, fresh
live tissue is often needed for fundamental experiments. For example, muscle and nerve tissues require careful handling and immediate use after isolation to study their responses to electrical stimuli. In in vivo experiments, live organisms are studied in their natural context, while in vitro studies use isolated cells, tissues, or organs to understand their behavior in a controlled environment.

Ultrasound is important tool for diagnosis and research that can be compared with other tools like radio-immunoassays. This has become an important tool applicable to farm and pet animals. Ultrasound uses high-frequency sound waves to produce images of soft tissues and internal organs. Electric current is applied to crystals in the transducer, producing vibrations characteristic of the crystals and resulting in sound waves. The sound beams that pass through the tissues are quite thin and a thin “slice” of tissue is sampled. The two dimensional image produced by ultrasound resemble to histological section. The sound waves are propagated or reflected by various tissues in different ways depending on their thickness and composition. The transducer receives those reflections and converts into electric signals and produces an echo on the ultrasound screen. Grey - scale is the term used for monochrome monitors on which a number of grey shades are distinguishable between black and white and constitute the image of reflected portion of tissue. Non-ecogenic (non echoic) tissues like fluids do not reflect sound waves and appear black on the screen. The echogenic tissues, having dense consistency, appear white as they reflect most portion of sound beam. Sometimes the artifacts create problem in the real image of the organ. These artifacts are created by certain tissues that cause bending or back and forth bouncing or blocking of sound beams. For imaging the reproductive tract of the domestic animals, B-mode (brightness modality), real time scanners are used. The amplitude of returning beams is reflected in the brightness of the dots on the screen. B-mode modulates brightness of the dots or pixels on the screen of echo displayer. The echo signals are presented as brightness of pixel corresponding to the amplitude of signal. The picture should be adjusted for clear display. In B-mode display the time-base brightness should be reduced just below the threshold of visibility so that even the smallest echoes could be visible.

RECTAL EXAMINATION

It provides practically all the information required.

It is the simplest, accurate and reliable method with no cost involved.

Things Required

A full arm rubber sleeve with attached glove or disposable plastic glove.
A rubber or plastic apron.
Non-irritant soap or lubricant.

Semen collection is the most important component of any frozen semen production programme as a high quality end product is not possible unless the raw material is of excellent quality. Therefore, all care should be taken to collect semen aseptically with the aim to harvest the best quality neat semen for processing. The person collecting semen should understand bull’s behaviour and should be friendly with him. Professional bull management results in increasing sperm output and enhancing productive life of the bulls. One must know potentials and limitations of the reproductive capacity of bulls. A highly professional and dedicated team of bull handlers and semen collectors is required for this purpose. The persons involved in bull management should be familiar with bull’s sexual behavior and male reproductive physiology. Preferably a veterinarian should collect semen.

Key Points

• Dogs can be fed a wide variety of chocolate and cocoa-based goods, particularly during holiday seasons, such as candy, cakes, cookies, brownies, and chocolate chips.

• Dogs that eat chocolate usually become very sick, but they also seldom die from it.

Introduction

Caffeine and theobromine are found in chocolate. Dogs' metabolisms of caffeine and theobromine differ from humans'. Because they contain more theobromine and caffeine, darker, bitter chocolates are considered to be more dangerous.

When a dog consumes too much chocolate goods, it can lead to major health problems like seizures, heart failure, and muscular tremors. In extreme situations, the dog may even pass away from cardiac or respiratory failure. Due to the fat and sugar content, it induces vomiting and diarrhoea even in non-toxic doses. Numerous substances found in chocolate are hazardous to animals. Although chocolate poisoning can affect a wide variety of animal species, including dogs, cats, horses, and rodents, it most frequently affects dogs. Theobromine and caffeine are the main harmful ingredients in chocolate. The amount of caffeine and theobromine in chocolate varies with kind. Dogs' metabolism of theobromine and caffeine differs from that of humans. Dogs are more sensitive because of this. Dogs who consume chocolate may become seriously unwell, even though it rarely results in death. When a dog eats too many chocolate-containing foods, such as cakes, cookies, brownies, candies, and chocolate chips, it might become poisoned.

Andrology is a branch of reproductive physiology that deals specifically with the study and treatment of male animals including humans. The study of reproductive physiology started with Aristotle around 350 B.C. in his book entitled Generation of animals, who believed that, the fetus arose from menstrual blood. He had no way of observing spermatozoa in the ejaculate or the beginning of embryo development. He assumed that, menstruation did not occur during pregnancy and the fetus was derived from menstrual blood. He also proposed that, the conversion of menstrual blood to a fetus was initiated by seminal fluid deposited in the male during copulation. Aristotle also assumed that, the testes were just like pendulum weights that kept the transport ducts from becoming kinked or plugged with seminal fluid. He has no research tools and his speculations were not very unreasonable. Later, a Dutch scientist named van Leeuwenhoek who developed a simple microscope made a major breakthrough in the study of reproductive physiology. Leeuwenhoek observed semen and discovered that it contained small particles that moved about and he named moving particles as ‘Animalcules’ and published a paper in 1677. The speculation was that the animalcule contained a fully formed individual within their cellular confines. Sperm head was thought to contain a microscopic yet fully formed individual. Later, Dumas concluded that, the animalcules now called spermatozoa were responsible for uniting with the ovum and producing an embryo. Over 2000 years elapsed from the speculations of Aristotle until it was understood that the spermatozoa from the male required for fertilizing ova from the female.

Introduction

A variety of glassware, plasticware, and other apparatus are used for experimental purposes in a laboratory. They need to be washed, cleaned, dried, and sometimes sterilized before they can be used in the next set of experiments. Glassware needs special care of handling during washing, drying, sterilization, etc. because even a minor mistake in handling of glassware may result in its cracking/breakage and it may become unserviceable. All of these may result in a delay in experimentation if spare piece of the glassware is not available or it may affect serviceability of the associated apparatus.

A large number of glassware such as beaker, flask, measuring cylinder, burette, test tube, etc. are regularly used in a laboratory, which requires careful handling during the different stages of experiment as well as after completion of the experiment while preparing them for another set of experimentation.

Glass being a complex silicate, its properties depends on the type of silicate anions in the structure and the cations formed. Thermal properties of glass changes by the addition of boron oxide (B2 O3 ); hence, borosilicate glass is extensively used in the laboratories. With this brief background information, let us discuss about the necessity, procedures, and precautions during washing, cleaning, drying and sterilization of laboratory-wares. Figure 3.1 shows various advantages of using borosilicate glass in a laboratory.

Good laboratory practices require clean glassware, because an experiment may give erroneous result if dirty glassware is used at any step of the experiment. Hence, the glassware must be physically and chemically clean; and in many cases, it must be microbiologically clean or sterile. The commonly used glassware in a laboratory include test tube, measuring cylinder, pipettes, beakers, flasks, microscopic slides, etc.

Introduction
Prenatal development is a crucial phase in the life of an organism during which the foundation for its future health and survival is established. In animals, the prenatal development is influenced by a complex interaction of genetic, chromosomal and environmental factors. These factors play a pivotal role in determining the phenotype, viability and overall health of the developing organism. The abnormalities of the structure or function of cells, tissues or organs present at birth are termed as congenital defects. These developmental defects can be caused by genetic, chromosomal and environmental factors.
A. Genetic Factors
Genes are the fundamental units of inheritance and their expression controls the development and functioning of all living organisms. In prenatal development, genetic factors provide the blueprint on which the formation and differentiation of tissues and organs is depend. These factors influence a range of developmental processes which include the timing and coordination of cell division and the development of specific structures.
1. Gene Expression and Regulation: Proper gene expression and regulation are essential for normal prenatal development. Genes are activated or suppressed at specific times during development and the precise regulation of these genes ensures the correct formation of tissues and organs. The mutations in key developmental genes can lead to malformations or developmental disorders.
2. Inherited Traits and Developmental Variation: Inherited genetic traits can influence the rate of prenatal development and the eventual size and characteristics of the offspring. For example, certain breeds of animals have genetic predispositions for faster growth rates, larger body sizes or distinct physical features which are evident even during prenatal development. Selective breeding practices in domesticated animals often aim to enhance these traits but they can also accidently introduce genetic disorders or vulnerabilities.
3. Epigenetic Modifications: Epigenetic factors such as DNA methylation and histone modifications also plays a crucial role in regulating gene expression during

Introduction

Measurement of pH of a solution and preparation of different types/strength of buffers are common practices in a laboratory, particularly in the Biochemistry and Molecular Biology laboratories. Therefore, in this chapter you will be acquainted with the procedures of measuring pH of a solution as well as preparation of some of the commonly used buffers in a laboratory.

Potential or Power of Hydrogen Ion (pH)

Measurement of pH of a solution is measuring the molar concentration of hydrogen ion [H+] in the solution, which is an indication of the acidity or basicity of the solution. The symbol pH stands for “power of hydrogen” and numerical value for pH is just the negative logarithm of the molar concentration of hydrogen ions [H+]. The ionic product of water (Kw ) is the basis for the pH scale. The total hydrogen ion concentration from all the sources and it can be experimentally measured.

The pH scale designates the concentration of H+ (and thus of OH−) in an aqueous solution, which ranges between 1.0 M H+ and 1.0 M OH−. The term pH is defined by the expression

Thus, the ionic product of water makes it possible to calculate the concentration of H+, with given concentration of OH−, and vice versa. The value of 7 for pH of a neutral solution is not an arbitrarily chosen figure; it is derived from the absolute value of the ionic product of water. A solution having pH greater than 7 is basic, and the concentration of OH− is greater than that of H+. A solution having a pH less than 7 is acidic.

Introduction
Gastrulation is a vital stage in the development of multicellular animals because it establishes the basic body plan, including the primary body axes (dorsal/ventral axis and the cranial/caudal axis) and prepares the embryo for organ formation. The process of cleavage leads to formation of blastula which is followed by gastrulation. The blastula consists of inner cell mass (Cell mass made up of darker blastomere and present at animal pole which is going to form embryo proper) and trophoblast (Cells made up of clear cells and arranged periphery near to Zona pellucid). The morphogenic changes occur during gastrulation is the formation of three germ layers. Gastrulation is the process in which single- layered blastula is converted into a trilaminar structure consisting of an outer ectodermal, a middle mesodermal and an inner endodermal layer and occupy their characteristic position in embryo. They will be give rise to different organs and extra embryonic membranes. The gastrulation is an important step of cell differentiation.
Gastrulation in Mammals
The process of gastrulation is variable among different domestic animals. It takes place in the uterus when the blastocyst is floating in the uterine fluid. After the degeneration of zona – pellucida, the cells located in the ventral margin of the inner cell mass separate out and extended ventrally along the trophoblast layer. Due to further proliferation, splitting (delaminate) and migration of cells from the inner cell mass, form a complete cellular lining on the inner site of trophoblast. This newly formed layer is called endoderm corresponds to the hypoblast of chick blastoderm. The remaining cells of the inner cell mass correspond to the epiblast of chick blastoderm. With formation of endoderm the blastocoel is divided into 2 cavities. The portion enclosed within endoderm is called primitive gut and area between endoderm and trophoblast layer is extra embryonic coelom. During this time trophoblast cells covering the inner cell mass degenerate and compact inner cell mass exposed and it is called as embryonic disc The embryonic disc occupies a position at the animal pole. Note: The development of the germ layers in mammals closely resembles that of birds with the formation of the primitive streak and primitive node.7

Introduction

Different types of culture media are used for culturing microbes and plant tissues. Preparing as well as sterilizing them properly following appropriate method with safety for the desired purpose are important parts of research work. In this chapter, we will discuss briefly about different types of media, their composition, preparation and sterilization in laboratory for microbial or plant tissue culture.

Culture Medium

Ingredients mixed to prepare solid, liquid or semi-solid substance to support the growth of microorganism or plant tissue in vitro (outside the body) is called culture medium. Frequently, it becomes important to grow microorganism or plant/animal tissue in vitro for any or all of the following purposes:

• To study characteristic features or properties of microorganisms.

• To identify the causal organism(s) of infection in a clinical sample, so that appropriate remedy can be determined.

• To culture/multiply microorganism or plant/animal tissues in vitro for research or commercial purposes.

• To prepare/produce biological molecules, vaccines, antigens, proteins, metabolites, etc. in vitro for research or industrial purposes.

A. Definition

A fracture is a break in the continuity of hard tissues like bone, cartilage, etc.

B. Etiology

(a) Extrinsic causes

Direct violence

Indirect violence

Introduction
Stem cells are the undifferentiated cells of the body which have inherent capacity to differentiate and proliferate into any cell type under programmed command. These cells perpetuate themselves through self-renewal by programmed pathways to give rise to new adult cells (Remya et al., 2014). According to plasticity, the stem cells are categorised into totipotent, pluripotent, multipotent and unipotent. Broadly they can also be classified as embryonic stem cells and adult somatic stem cells. Totipotent stem cells are those which can give rise to all types of cells along with placental membranes whereas pluripotent stem cells give rise to all cell types except placental membranes. The multipotent set of stem cells can give rise to more than one cell type and unipotent ones can differentiate into only one type of cells. Mesenchymal stem cells (MSCs), which fall under the multipotent stem cells category, have the multilineage potential to differentiate into many mesenchymal lineages like osteocytes, chondrocytes, adipocytes etc. (Kim et. al., 2013). They can be easily isolated from the adipose tissues, bone marrows, muscles, liver, umbilical cords, lungs etc. and can be easily proliferated in vitro. MSCs were first identified from the bone marrow in a pioneering study by Fredenstein et al (1976) who isolated the bone forming progenitor cells from rat bone marrow. Although the MSCs represent very small fraction of 0.001-0.01% of total nucleated marrow cells, they can be isolated and differentiated into multiple lineages under defined culture conditions. They are generally isolated from iliac crest, tibial and femoral marrow compartments along with thoracic and lumbar spine in large animals. Stem cells have been used for cellular therapy and tissue engineering for quite a period of time owing to their regeneration potential. They are unspecialized cells with the ability to renew themselves for long periods without significant changes in their general properties. These cells under the influence of appropriate signals can differentiate into specialized cells with a phenotype distinct from that of the precursor (Kim et al., 2013). It may be that stem

Artificial insemination Technology is a high cost and labour intensive technique in sheep and In India, sheep are reared by economically weaker sections of the society and any advanced technique may take much time to reach their flocks.  Considerably more research work has been done in AI with sheep than with goats. However, the equipment and techniques are very similar for the two species. Goat semen may be stored and frozen more successfully than ram semen.

Introduction

Flowering plants (Angiosperms) are identified by their morphological characteristics like flower, fruit and seeds that help their taxonomic characterization into different species, genera, families and orders. The floral characters which are used for taxonomic characterization of plants include the type of inflorescences, perianth structure, floral symmetry, arrangement of floral leaves, type of androecium, stamens, gynoecium, carpel, ovule, etc. The type of fruit and seed also play important roles in taxonomic classification. In this chapter we will briefly discuss about various morphological features of flowering plants (in botanical terms) that are useful in taxonomy.

Nomenclature of Plant

Nomenclature of plant is the formal and scientific naming of plants. It is related to but distinct from taxonomy for grouping and classifying plants and provide botanical name.

The scientific/botanical nomenclature started with Species Plantarum by Carolus Linnaeus in 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN).

ICBN and ICN

International Code of Botanical Nomenclature, (ICBN) was adopted by the VIIth International Botanical Congress held in Stockholm, July1950. While the International Code of Nomenclature for algae, fungi, and plants (ICN) was adopted by the XVIIIth International Botanical Congress held in Melbourne, Australia in July 2011.

Introduction
Reproduction involves the intricate interplay of physiological processes to ensure the successful growth and development of the embryo and fetus. Three key processes— implantation, placentation, and the establishment of fetal circulation—are fundamental to a viable pregnancy. These stages ensure the fetus receives adequate nutrients, oxygen, and support for development. Below is a detailed elaboration of each process.
1. Implantation
Implantation is the process by which the blastocyst (a hollow structure formed in the early development of mammals) embeds itself into the uterine wall. It is the first critical step in establishing a pregnancy.
Phases of Implantation
1. Apposition: The blastocyst loosely attaches to the endometrium (the inner lining of the uterus).
2. Adhesion: The trophoblast cells (outer layer of the blastocyst) firmly attach to the uterine lining.
3. Invasion: The trophoblast differentiates into two layers: Cytotrophoblast: The inner cellular layer that serves as the proliferative zone. Syncytiotrophoblast: The outer multinucleated layer that invades the endometrium, facilitating deeper embedding.
Significance
Implantation typically occurs 6–10 days after fertilization.
It ensures the establishment of an early connection between the embryo and maternal blood supply.
Successful implantation depends on hormonal regulation, especially the roles of estrogen and progesterone, which prepare the endometrium to be receptive.