eChapters

Etiology

Intestinal spirochetes colonise the large intestine of avian, swine and humans.

Family spirochaetacae has six genera, of which Borrelia, Serpulina and Treponema have species pathogenic for animals. Avian intestinal spirochetes are grouped in four: Serpulina hyodysenteriae, S. intermedius, S. pilosicoli (Angullina coli) and an unnamed group.

Chicken S. hyodysenteriae is different from porcine one. S. hyodysentriae, Angullina coli and unclassified groups are present in the USA, whereas S.intermedius is in Europe and Australia.

Avian intestinal spirochetes are gram negative, stain brown with silver impregnation techniques and blue in Wright-Giemsa stain. They can be divided in 3 pathotypes 1) severely pathogenic 2) Mildly to moderate pathogenic and 3) subclinical or apathogenic.

LL is a retrovirus-causes, neoplastic disease of semi-mature or mature chickens characterized by a gradual onset in a flock, persistent low mortality and neoplasia of, the bursa of Fabricius (BF) with metastasis to many other internal organs especially the liver, spleen and kidney.

Introduction

From avian species alone approximately 20 mycoplasma serotypes have been isolated and characterised. Out of them, three serotypes (M. gallisepticum, M. meleagridis and M. synoviae) are most typical and pathogenic. A serotype M. iowae causes low hatchability in turkeys. Mycoplasmas are bacteria that lack cell wall and belong to the class Mollicutes. Although they have been considered extracellular agents, scientists admit nowadays that some of them are obligatory intracellular microorganisms, whereas all other mycoplasmas are considered facultative intracellular organisms

Etiology

Avian Nephritis Virus (ANV), an RNA virus is Astro virus under the genus Avastrovirus in Astroviridae family. Strains of ANV exist. ANV is very resistant and stable in the environment.

A. Answer the following questions

1.    Why ducks are highly susceptible to aflatoxicosis?

Ans: Ducks are about 200 times more sensitive than broilers and layers. Ducks contain a very high level of enzyme in the livertoconvert aflatoxinB to “aflatoxacol”. Besides, aflatoxin metabolism is 90 times faster in the duck liver than in rat liver.

2.    Why duck should have never access to feed without water?

Ans: Most mashes form a sticky paste when mixed with saliva and adhere to the papillae and other structures bordering the outer margin of the tongue and upper and lower bill. This caking interferes with the movement of the food mass to the tongue resulting in reduction of food intake and increase in feed wastage which occurs when the duck attempts to shake or wash off the mash adhering to its mouthparts.

Poultry sector in India has grown from a backyard activity into a major commercial activity in four and half decades. Poultry is one of the fastest growing subsectors of agricultural sector in India. Within the poultry sector, broiler production is growing faster than egg production and about 66.7% of the total output (in value term) comes from the poultry meat sector and only 33.3% from egg production (FAO, 2008). India ranks fifth in chicken and sixth in duck population. Presently, India is world’s third largest egg producer and the fifth major producer of chicken meat (FAO, 2010). Poultry is today the major source of meat in India. As per an estimate about 2 million people are employed, fully or partly, along the poultry value chain and that an increase in annual per caput availability of one egg or 50 gm or poultry meat generates about 20,000 to 25,000 full time jobs (Ciamarra & Otte, 2009). Distribution of chicken and duck population as well as poultry meat and egg production among different regions, countries of the world and among different Indian states has been already discussed in chapter one of this book.

Introduction

Avian salmonellosis is the term used to describe a large group of acute or chronic diseases caused by one or more members of the bacterial genus Salmonella, which is a member of the large family Enterobacteriaceae. Domestic poultry is known to constitute the largest single reservoir of Salmonella organism existing in nature. They include host specific and nonmotile members of the genus S. enterica subspp. enterica pullorum/gallinarum. If the infection of poultry is due to other Salmonella organisms other than Salmonella enteric subspp. enterica gallinarum/pullorum, the infection is then referred to as paratyphoid.

Poultry is one of the most emerging growth components of Indian agriculture, with egg and meat production rising at the rate of 8-10% per year when compared to crop production (1.5 - 2% each year). In India, the poultry population stood at 851.81 million in the 20th livestock census, an increase of 16.8% over the 19th census. Poultry sectors contribute 1% of national GDP and 25% in livestock GDP (FAO, 2021). According to DAHD’s 2022 report, our nation produces 122.05 billion eggs and 4.47 million tonnes of poultry meat altogether. India ranks eighth in terms of total meat production and third in terms of total egg production (DAHD, 2022).

Introduction

Avian medicine is a rapidly growing field, with an increasing number of exotic bird species being kept as pets. However, the unique anatomy, physiology, and behaviour of these birds present several challenges as well as new opportunities for veterinarians and researchers.Now a day’s birds are gaining popularity over dogs and cats because of various reasons listed below:

a. They are more suited in present life style as can be suited well in small spaces.

b. They require low maintenance with relative low cost of maintenance and live longer life.

c. They form very strong bonds with their owners.

Birds can be classified into different families, such as Psittaciformes, Passeriformes, Columbiformes, Piciformes, Anseriformes, Galliformes etc. containing numerous species (>10,000). The first documentation of parrot as a pet was found in Rig Veda, written more than 3000 years ago. Evidence of bird keeping is observed in ancient civilizations of Greece, Rome, China and Egypt. In Greek mythology, Raven (a crow) was mentioned as a symbol of good luck and was associated with God Apollo (God of prophecy). Crows are also considered as ancestors in Hindu mythology and food (pinda) is offered to crows during ritual of paying homage to dead persons. In most of the countries psittacine and passerine birds are preferred as pet birds.

The Indian agriculture is on the threshold of a second revolution. It is becoming increasingly clear that the next leap will come from the Information and Communication Technology (ICT). Even though ICT has developed very well, its penetration to the farming community seems to be very less. At the same time, it is difficult for the extension agent to personally attend the queries of every farmer individually. With the decreased number of extension workers, there is a need to use the latest technologies for delivering extension services.

β-glucans are carbohydrates made of complex glucose polymers that provides the major structure found in the cell wall of yeast, fungi, algae, and cereal grains such as oats and barley. The structures of β-glucans vary depending on the original source and the type of linkages present on the glucose polymers. β-glucans consist of a backbone of glucose molecules linked at the 1 and 3 carbon atoms (Jacob and Pescatore, 2017). The six-sided glucose rings are connected together in linear or branched forms with glycosidic linkages. The structure of these glycosidic linkages will affect the functionality of the β-glucan molecules.

Bar chart: The bar chart or diagram is one of the ways of graphically displaying categorical data. A bar chart is identical to a histogram, except that in a bar chart the rectangles representing the various frequencies are spaced, thus indicating that the data is categorical. The bar diagram is used for variables measured on nominal or ordinal scales.

Bovine babesiosis is a significant febrile disease, primarily affecting cattle and buffalo, transmitted by ticks. The disease is marked by the rapid proliferation of parasites within the bloodstream, leading to the extensive destruction of red blood cells. This results in a cascade of clinical symptoms, including anemia, jaundice, hemoglobinuria, and splenomegaly, with the potential for severe cases to culminate in death. The acute form of bovine babesiosis is particularly severe, often characterized by these pronounced symptoms, which can lead to rapid deterioration in the affected animals. Babesiosis is not merely an acute illness but can also persist as a chronic infection. Chronic bovine babesiosis is typified by ongoing anemia and varying degrees of weight loss, reflecting the enduring impact of the parasite within the host. Economically, this disease poses a formidable challenge, especially in regions where cattle are most susceptible. Since the first description of Babesia bovis by Victor Babes in Romania in 1888, numerous distinct species have been identified, each contributing to the global burden of this disease (Hunfeld et al., 2008). The impact of bovine babesiosis on livestock improvement efforts in endemic regions is profound. The introduction of susceptible, naive animals into these areas often leads to significant losses, as these animals are highly vulnerable to the disease.

Abstract

Bacilli, a group of endospore forming bacteria present in soil, contribute directly or indirectly to crop productivity. Bacilli have many physiological unique traits like multilayered cell wall, stress resistant endospore formation, secretion of peptide antibiotics, peptide signal molecules, extracellular enzymes, which make them ubiquitous and assist to their survival under adverse environmental conditions for long time.

B.anthracis causes anthrax in animals and Wool sorter’s disease, hide porter’s disease, Malignant Pustule in humans. B.cerus causes food poisoning in humans. Other bacillus in this group is non-pathogenic and they are called as anthracoids. B.licheniformis is an emerging pathogen and it is implicated in sporadic abortions in cattle and sheep.
Systematics
Domain : Bacteria
Phylum : Firmicutes
Class : Bacilli
Order : Bacillales
Family : Bacillaceae
Genus : Bacillus
Species : B. anthracis, B. cereus, B. subtilis, B. mycoides,
B. megaterium, B.mesentricus
Family Characters
They are gram +ve large rods, aerobic (facultative anaerobic), endospore forming, capsulated, mostly catalase positive and fermentative organisms. They are motile by peritrichous flagella.
Bacillus Anthracis
History
• Discovery of the anthrax bacillus is credited to Davaine and Rayer (1863 –1868).
• Considerable historic interest attached to anthrax bacilli;

Backwardation : When a commodity is valued more highly in a spot market (that is, when it is for delivery today) than in a futures market (for delivery at some point in the future). Normally, interest costs mean that futures prices are higher than spot prices, unless the markets expect the price of the commodity to fall over time, perhaps because there is a temporary bottleneck in supply.

Balance of payments : The total of all the money coming into a country from abroad less all of the money going out of the country during the same period. This is usually broken down into the current account and the capital account. The current account includes : *visible trade (known as merchandise trade in the United States), which is the value of exports and imports of physical goods; *invisible trade, which is receipts and payments for services, such as banking or advertising, and other intangible goods, such as copyrights, as well as cross-border dividend and interest payments; *private transfers, such as money sent home by expatriate workers; official transfers, such as international aid. The capital account includes : *long-term capital flows, such as money invested in foreign firms, and profits made by selling those investments and bringing the money home; *short-term capital flows, such as money invested in foreign currencies by international speculators, and funds moved around the world for business purposes by multinational companies. These short-term flows can lead to sharp movements in exchange rates, which bear little relation to what currencies should be worth judging by fundamental measures of value such as purchasing power parity. As bills must be paid, ultimately a country’s accounts must balance (although because real life is never that neat a balancing item is usually inserted to cover up the inconsistencies).

Balanced budget : When total public-sector spending equals total government income during the same period from taxes and charges for public services. Politicians in some countries, such as the United States, have argued that government should be required to run a balanced budget in order to have sound public finances. However, there is no economic reason why public borrowing need necessarily be bad. For instance, if the debt is used to invest in things that will increase the growth rate of the economy—infrastructure, say, or education—it may be justified. It may also make more economic sense to try to balance the budget on average over an entire economic cycle, with public-sector deficits boosting the economy during recession and surpluses stopping it overheating during booms, than to balance it every year.

Backyard farming is an unorganized sub sector of poultry industry. India has nearly 60 percent of its population living in rural areas. However, in the present scenario most of the commercial poultry production is concentrated in urban and semi urban areas due to high demand. Only 25 percent population living in urban area consumed about 75-80 percent of eggs and poultry meat. Nonavailability of poultry products and low purchasing power of the rural people devoid them of access to the highly nutritious products like egg and meat, thereby, resulting in malnutrition. Free range and small scale semi commercial
back-yard poultry production can be advantageously promoted in rural areas, as the large commercial poultry production continues to be concentrated in urban and semi-urban locations. It can be used as a powerful tool for alleviation of rural poverty, eradication of malnutrition and creation of gainful employment in vast rural areas (Sharma and Chatterjee, 2009; Rajkumar et al., 2010).
The most basic and simple backyard production system involves a few hens and a cockerel is essentially a closed system. Home-produced fertile eggs arehatched to provide replacements, birds feed by  scavenging or are provided with household scraps and crop by-products; there are virtually no veterinary inputs and the remaining eggs and meat produced are consumed within the household. Such very simple subsistence poultry production systems are probably quite rare. Producers with even slightly larger flocks, generate cash income from the sale of eggs and birds within the local community. Transactions may take place directly between producers and consumers, but traders and other market intermediaries may be involved, selling on to other sectors of the poultry industry. Village or backyard production systems are widely distributed and exist in both rural and urban areas. It is estimated that today in India, about 18 percent of total poultry output is derived from backyard production. 

Importance of Backyard Poultry Farming in India

Commercial chicken production in India has undergone a remarkable change in the last three decades. While India is among the top five chicken producing and top seven duck producing countries in the world, the gap between the demand and production is still alarming. Average per capita availability of eggs in big cities is 170 while it stands at 9 eggs per annum in the rural areas. Though the commercial poultry sector has made a stupendous progress over the years, the conventional free and backyard poultry farming remain neglected. Backyard poultry farming contributes around 11% to the national production while in certain states like U.P. around 60% of the poultry population is indigenous fowls reared under backyard system. The backyard sector contributed to 23 per cent of the total egg production in 2005-06.

Commercial chicken production is capital intensive and is generally concentrated in and around urban areas. There is a wide disparity in consumption of the poultry products between urban and rural population. Around 75% of country’s population living in the rural areas has limited access to the protein rich poultry products. Protein deficiency is quite common in the diets of rural people. Adoption of rural poultry farming may ameliorate the high incidence of protein hunger in growing children and pregnant women.

It has been seen that the commercial birds have poor immunity against common poultry diseases. As production is inversely proportional to the viability traits, the nutrients absorbed are mostly diverted for growth in commercial chicken. On the other hand, indigenous birds reared in rural areas are resistant to many diseases and pests. Unlike the local breeds maintained in villages, the commercial breeds require high level of input pertaining to feed and health care to maintain production and check mortality.

Size – Shapes - Arrangements – Morphology

Bacteria are very small, most being approximately 0.5 to 1.0 mm diameter. Smallest bacteria are Mycoplasmas, as small as 0.2 micrometers (almost as small as largest poxviruses).

Accepted wisdom is that bacteria are smaller than eukaryotes. But certain cyanobacteria are quite large; Oscillatoria cells are 7 micrometers diameter, size of red blood cells. And certain eukaryotes (e.g. Nanochlorum eukaryotum) are very small, only 1 to 2 micrometers, but true eukaryotes (nucleus, chloroplast, mitochondrion are present). So size difference is, like many generalizations, only a useful yardstick, not an absolute truth.

Epulopiscium fishelsoni, discovered in 1985 in intestinal tract of sturgeonfish, is an enormous, cigar-shaped cell, as large as 80 x 600 micrometers (that’s 0.6 mm, large enough to be seen by the naked eye). Amazingly, this cell is prokaryotic! Initial evidence by EM was hard to believe, but confirmed rRNA comparisons with other organisms, a cousin of Gram-positive Clostridium genus.

The relative size of the bacteria are as follows :