eChapters

Pathology of nutritional deficiency diseases are described in chapter etiology of this book. However, specific deficiency of nutrition that leads to development of clinical signs and lesions in poultry are summarized as under (Fig.2.1 & Fig.2.2):

Vitamin Deficiency

1. Hypovitaminosis A

• Vitamin A is considered infection resisting vitamin because it facilitates the proper development of bursa, immunity and epithelium on mucosal and skin surfaces.

• Deficiency of vitamin A leads to swollen glands in oesophagus i.e. nutritional roup.

Trypanosomosis

Trypanosomosis is an infectious disease of animals caused by protozoan parasite and characterized by emaciation, enlargement of spleen and lymph nodes, petechiae on serous membranes, ulceration on tongue and gastric mucosa and gelatinous exudate in subcutaneous region.

Etiology

• Trypanosoma evansi

Pathogenesis

The disease is mainly transmitted through bite of flies like Tabanus, Stomoxys, Haematopota etc. The carrier animals remain as potential source of infection. The pathogenesis of disease is not completely known. After entering in mammalian host, trypanosomes multiply in blood stream by binary fission leading to parasitaenia. The parasites has variable surface glycoproteins which cause continuous exposure of immune system leading to hyperplasia of spleen and lymph nodes. In chronic cases, due to formation of antigen- antibody complexes glomerulonephritis and vasculitis is seen.

Roundworms (Nematodes)

1. Ascaridia galli

A. galli is the common roundworm of poultry seen in intestines at the time of necropsy. This parasite may cause retardation of growth, loss of egg production, catarrhal enteritis and sometimes mortality due to obstruction of gut (Fig.9.1).

Etiology

• A. galli parasites are grey, thread like 5-10 cm in length.

• Eggs are elliptical with thick and shiny wall.

Pathogenesis

Transmission occurs through faecal - oral route. The eggs may survive for several months in litter and they take at least 10-15 days to develop the infective stage. The eggs of parasites hatch in proventriculus or intestine to develop fully grown parasite within 40-50 days.

Spongiform encephalopathy

Spongiform encephalopathy is an infectious disease of animals caused by prion proteins and characterized by presence of vacuoles in brain.

Etiology

• Prion proteins

• Sheep – Scrapie or Ovine spongiform encephalopathy

• Cattle - Bovine spongiform encephalopathy (Mad cow disease)

• Feline encephalopathy

Pathogenesis

Scrapie is also known as ovine spongiform encephalopathy. The principle means of transmission of disease is from infected mother to their lambs early in life; placental transmission has also been reported. The incubation period of disease is very long (2-5 year). The clinical form is restricted in adults. The prion proteins (PrP) occur normally in the central nervous system of all domestic animals and man bounded with neuronal surface. Animal susceptible to prion disease have a gene (PrP gene) which encodes for normal “Prion protein (PrP)” or “cellular prion protein (PrPc). In scrapie prion protein (PrPsc)/ scrapie associated fibril protein (SAI) is generated which are resistant for protease digestion. Accumulation of PrPsc in neural tissues appears to be the cause of the pathology in prion disease. When prion protein contaminated meat and bone meal are fed to the cattle as part of their concentration, the agent (prion) got introduced into cattle. Prion protein (PrP) on reaching brain slowly and progressively converted into and abnormal form (PrP sc) and this abnormal protein causes development of lesions including vacuolation in nerve cells.

Anaplasmosis

Anaplasmosis is an infectious disease of animals caused by a rickettsia and characterized by icterus, enlargement of spleen, pale tissues, thin watery blood and petechiae over serous membranes (Fig.4.1).

Etiology

• Anaplasma centrate

• A. marginale

• A. ovis

Pathogenesis

The disease is transmitted through bite of tick (Boophilus), biting flies (Tabanus) and also in some cases due to mosquitoes. It is intra cellular organism and multiplies inside the erythrocytes by binary fission. The infected erythrocytes are engulfed by the cells of reticuloendothelial system (spleen, bone marrow). The process of erythrophagocytosis cause extra vascular haemolysis leading to anemia. It also causes autoimmune reaction leading to lysis of erythrocytes.

Spirochetosis

Spirochetosis is caused by a spiral shaped organism Borrelia anserina and characterized by greenish diarrhoea, enlarged and mottled spleen, small necrotic patches on liver and linear haemorrhage in proventriculus. This disease is transmitted by a tick Argas persicus and thus also known as “tick fever” or “tick paralysis”.

Etiology

• Spirochete Borrelia anserina

• Spiral shape 8-24m long and 0.2 to 0.3 m wide microorganism having 8-11 spirals.

• Stained with aniline dyes

Leptospirosis

Leptospirosis is an infectious disease of animals caused by spirocheate Leptospria sp. and characterized by widespread haemorrhage in visceral organs, nephritis, icterus, hepatitis and anemia (Fig.6.1).

Etiology

• Leptospira ictehaemorrhagae

• L. pomona

Pathogenesis

The organism is transmitted through direct contact with urine of infected animals or ingestion of urine contaminated feed or water. It can also be transmitted through aborted fetuses and infected uterine discharges. The organism enters through abraded skin and mucous membrane and reaches in blood and multiplies rapidly in blood producing septicemia and high rise in body temperature. Thereafter the organism localizes in the kidneys leading to acute or chronic nephritis. In kidneys, it multiplies in proximal convoluted tubules (PCT) and is excreted in urine which acts as source of infection.

Developmental Anomalies

Aplasia

Absence of one or both kidneys. Absence of one kidney is observed in animals with compensatory hypertrophy of another kidney and such animals may survive well.

Hypoplasia

The size of kidneys remains small as they don’t grow properly due to defect in a single recessive autosomal gene.

Cyst in kidney

Single or multiple cysts in pig and dog kidney are reported with tinged yellow colour. They may arise from nephron due to its distension. Presence of multiple cysts is also termed as congenital polycystic kidney.

Type-I cysts are formed due to dilation and hyperplasia of collecting tubules resulting in spongiform kidneys. In such neonates cystic bile ducts are also present.

Cannibalism

Cannibalism is a bad habit of birds in which the birds attack their fellow birds and eat their flesh. It is done through sharp end of beak, which causes deep wounds specially on vent. Sometimes the wounds are so deep that leads to death of affected bird. Two types of cannibalism vices are common i.e. vent pecking and feather pecking.

Cause / Predisposing Factors

• Over crowding

• Genetic predisposition

• Hemorrhage in external genitalia

• Protein deficiency (arginine and methionine deficiency)

• Loss of feathers • Wounds

• Prolapse of cloaca

Foot and Mouth disease

Foot and mouth disease is a contagious viral disease of cloven footed animals caused by a picorna virus and characterized by presence of vesicles in oral mucosa and foot (Fig.1.1).

Etiology

• RNA virus of picornaviridae family

• Picorna virus

• Serotypes A,O,C, SAT-1, SAT-2, SAT-3, Asia-1, serotype ‘O’ is most common in India.

Pathogenesis

Inhalation is the main route of infection in ruminants; however, ingestion of contaminated feed and water, inoculation of contaminated vaccines, insemination with contaminated semen and contact with fomites such as clothing, instruments etc. may also transmit the infection. When animal gets infected through respiratory tract, viral replication starts in pharynx followed by viraemic spread to other tissues and organs like epithelium of mouth. Viral excretion commences about 24 hours prior to the onset of clinical form of disease and continues for several days. The aerosols of infected animals contain large amount of virus particularly of swine. Large amount of virus is excreted in milk. In cattle and sheep, virus may be detectable up to 2 years and 6 months of exposure, respectively.

Feline Leukemia

Feline leukemia is an infectious viral disease of cats, lion, tiger etc. caused by oncorna virus and characterized by malignant lymphoma, lymphocytosis and immunosuppression. It is also known as feline lymphoma or feline lymphosarcoma.

Etiology

• Oncorna virus of retroviridae family

• Type C oncorna virus, RNA virus has reverse transcriptase

Pathogenesis

The virus is transmitted horizontally through salivary and nasal secretions of sick cats. It affects lymphocytes causing their proliferation leading to production of neoplastic growth.

Characteristic symptoms

• Enlargement of superficial lymph nodes

• Lymphocytosis

• Chronic diarrhoea

• Abortion

Pathology of Upper Respiratory Tract

In many infectious diseases, there is inflammation of mucosa of upper respiratory passage leading to nasal discharge which is catarrhal, purulent or fibrinous, depending on the type of infection. The infection may extend to lower parts of respiratory tract and reach the lungs causing pathological alterations. Rhinitis is the inflammation of nasal mucosa (Fig. 4.1). Sinusitis is the inflammation of sinuses e.g. frontal sinusitis in dehorned cattle. The larvae of botfly Oestrus ovis enter the nasal passage and migrate up to frontal sinuses and turbinate bones and cause mucopurulent inflammation. Similarly, leeches (Dinobdella ferox) is known to cause nasal cavity inflammation in domestic animals and suck blood. Rhinitis is caused by Bordetella bronchiseptica in pigs and is characterized by mucopurulent exudate, disappearance of nasal septum, retarded growth of snout and plugging of passage by solidified exudate and dead tissue. This condition is known as porcine atrophic rhinitis. Epistaxis is bleeding from nasal passage due to trauma, neoplasm (Fig.4.2A) and ulcerative lesions as a result of infections (Fig.4.2B). Pharyngitis is the inflammation of pharynx while laryngitis is the inflammation of larynx.

Pranab Mukherjee in his budget speech delivered on 26 February 2010 announced: ‘We are now ready with the draft Food Security Bill which will be placed in the public domain very soon.’  Although no official draft has been placed on the website of the concerned Ministry, several leading organisations and individuals have questioned the adequacy of the steps proposed to be taken under the Bill for achieving the goal of a hunger-free India.  Based on Article 21 of the Constitution, the Supreme Court of India has rightly regarded the right to food as a fundamental requirement for the right to life.  Many steps have been taken since Independence to adopt Mahatma Gandhi’s advice for an antyodaya approach to hunger elimination. In spite of numerous measures and social safety net programmes, the number of undernourished persons has increased from about 210 million in 1990-92 to 252 million in 2004-06.  About half of the world’s under-nourished children are in India.  Also, there has been a general decline in per capita calorie consumption in recent decades.  Grain mountains and hungry millions continue to co-exist.

Growth of a microorganism implies an increase in amount of protoplasm, formation of new structures and eventually formation of new cells. Balanced growth means cell components increase in proportion to each other and unbalanced growth means cell components increase in a non constant relationship to each other

Microbial growth and growth curve

Phases of growth

When bacteria are grown in the laboratory in liquid medium, the medium becomes cloudy or turbid. It is possible to measure the increase in numbers of bacteria at various time intervals and plot the values on a graph representing a growth curve.

Lag Phase: When cells are first inoculated into fresh medium containing all the nutrients they require, they take a short time to adapt before they start to divide. This is termed the lag phase.

ABSTRACT

Information Technology includes computers and communication technology along with associated software. I.T. can be defined as the technology of creation, processing, storage, retrieval and transmission of data and information. Transmission of data and information between through local national, regional and global telecommunication channels are not new to us. Computer networks have been the real facilitators of data and information interchange in the individual and corporate levels. LANS and WANS are the good examples of it. Developing countries have a critical stake in how successfully they cope with the trade, environmental, energy, healthy, agricultural, industrial, population and other challenges facing them as they enter the information age. The World is experiencing an explosive growth of IT at the moment. There have been tremendous impacts of I.T. on the trade, commerce and industries of the globe.

Genus : Asimina 
Species : triloba (L.) Dunal
Family : Annonaceae
Chromosome No. : 2n = 18

Uses

The delicious pawpaw fruits are used as dessert. The red or brown streak wood is light in weight hence not used for furniture or allied work. On account of its handsome foliage, large leaves and attractive form, it provides additional attraction when planted in gardens.

The present study was designed to assess the cardio-protective role of oleic acid in myocardial injury. Myocardial injury was induced in rats by intra-peritoneal injection of isoprenaline (ISO; @ 110 mg/kg b.wt) for two consecutive days at 24 h interval. Oleic acid was administered orally (@ 5 mg/kg b.wt or 10 mg/kg b.wt) for 21 days before inducing myocardial injury to evaluate its ameliorative potential. Samples (blood, heart) were collected from different groups of experimental animals 24h after last injection of isoprenaline. Besides evaluation of heart weight to body weight (HW/BW) ratio, myocardial infarct size, oxidative stress parameters and haemato-biochemical parameters, cardio specific biomarkers of injury, ECG, isolated right atrial response and mRNA expression of gene coding for cardiac uncoupling protein-2 (UCP-2) were also quantified. Isoprenaline administration significantly increased the HW/ BW ratio, myocardial infarct size, lipid profiles (total cholesterol, HDL-C, triglyceride) in ISO-induced myocardial injured rats.

The polymerase chain reaction (PCR) is a very powerful new method used for in vitro to amplify a deoxynibonuclic specific region that lies between two regions of known DNA sequence single molecule to million folds in short time. This is achieved by an enzyme taq. DNA polymerase which is thermostable using this enzyme can synthesize microgram quantities of DNA of specified length and sequence from pictogram quantities of complex template in a few hours time.

Many Bacillus species are capable of producing a wide variety of secondary metabolites that are diverse in structure and function. The production of metabolites with antimicrobial activity is one determinant of their ability to control plant diseases. The activity is determined using PCR. PCR consists of an exponential amplification of a DNA fragment, and its principle is based on the mechanism of DNA replication in vivo. dsDNA is denatured to ssDNA, duplicated, and this process is repeated along the reaction according to the following formula

Introduction
In recent years crop yields have increased significantly due the development of new varieties and cultivars. Certain characteristics, like disease resistance, plant height, yield potential, and maturity period, set one variety of a cultivated crop species apart from other variations of the same species. A key element of contemporary agriculture is the precise identification of crop types, which is essential for plant breeding, seed certification, and the defence of intellectual property rights. The increasing demand for improved crop varieties with increased yield, disease resistance, and environmental adaptability has demanded the development of accurate methods for differentiating cultivars (Hannah, 2024). Traditional techniques of variety identification rely on morphological, biochemical, and agronomic features, which can be altered by environmental conditions and are generally time-consuming and labour-intensive. Various molecular marker systems have been developed to differentiate plant varieties and species of agricultural and horticultural significance. For effective seed quality control programs and the preservation of breeders’ rights, it is essential to define the identity, genetic purity, and stability of plant varieties. According to Yuan et al., (2022), precise variety identification is essential for determining genetic purity, analyzing genetic diversity, improving germplasm for better agronomic qualities, and getting rid of duplicate accessions.
For plant protection and production systems of Intellectual Property Rights (IPR) and Plant Biodiversity Register (PBR), accurate cultivar identification is crucial. According to Ghosh et al. (2001), molecular marker approaches are pertinent to PBR registration in the following ways. (1) In order to establish a set of comparison cultivars, genetic distance analysis between the candidate cultivar and the current pool of cultivars is performed. (2) The contribution of the comparison cultivar to PBR registration is then determined, and (3) the use of DNA markers to identify cultivars in cases where PBR infringement is alleged is investigated. The capacity of PCR-based markers to amplify particular DNA sequences has made them popular among molecular marker techniques, enabling accurate identification of genetic variations. Although conventional approaches are still employed for Plant Variety Protection (PVP), molecular techniques can be useful adjuncts that increase the effectiveness of accomplishing this goal. During variety certification, additional information from isozyme analysis, RFLP, SSR, SNP, or other genetic fingerprinting methods can be added to cultivar descriptions. Plant varieties can be legally protected on the basis of precise and unique molecular marker data. Crops with little morphological variation benefit greatly from molecular methods. To guarantee complete protection of cultivars, it is ideal to use both botanical and molecular evaluations (Yu and Chung, 2021). Amplified Fragment Length Polymorphism (AFLP), Random Amplified Polymorphic DNA (RAPD), Simple Sequence Repeat (SSR), and Inter Simple Sequence Repeat (ISSR) are the four main PCR-based markers used in crop variety identification that are the subject of this chapter. In plant genetics, each of these marker systems has special qualities, benefits, and uses. While AFLP markers give high resolution and genome-wide coverage, RAPD markers offer a rapid and economical method of polymorphism detection. Due to their high polymorphism and co-dominant inheritance, SSR markers—also referred to as microsatellites—are perfect for genetic mapping