eChapters

Subclavian artery

The fore limb is chiefly supplied by the subclavian artery (Fig. 5-4 A). It originates from the brachiocephalic trunk within the thoracic cavity. The left subclavian detaches from the brachiocephalic trunk opposite the second rib, passes craniodorsally towards the thoracic inlet winds around the cranial border of the first rib and then courses caudoventrally through the axillary space between the subscapular and teres major muscles as the axillary artery. It gives off the subscapular branch and continues as the brachial artery. The right subclavian is the direct continuation of the brachiocephalic trunk after the later gives off the bicarotid trunk opposite the first rib. It gets exit through the thoracic inlet, winds around the cranial border of the first rib and then continues as the right axillary artery and thereafter as the brachial artery similar to the artery of the left side.

Arteries of neck

Common carotid artery

The right and left common carotid arteries arise from the bicarotid trunk as it bifurcates on the ventral surface of the trachea at the thoracic inlet. In their course to reach the head, both of these, the right and left, common carotid arteries ascend through the neck along the ventrolateral aspect of the trachea and oesophagus respectively. During this course each of these arteries is accompanied by the vagosympathetic trunk dorsal to it, recurrent laryngeal nerve ventral to it and the internal jugular vein lateral to it. All these structures are enclosed in the carotid sheath. The external jugular vein is separated from the common carotid artery by the omohyoideus and sternocephalicus muscles. The right artery crosses the lateral surface of the trachea and passes along its dorsolateral surface and finally reaches to the lateral surface of the larynx and pharynx in front of the digastricus muscle ventral to the jugular process of the occipital bone. The left artery crosses the trachea and oesophagus and continues along its dorsolateral surface to the level of the third cervical vertebra. Here the oesophagus inclines towards the median plane and the artery follows the lateral surface of oesophagus till it reaches to the lateral surface of the larynx and pharynx just in front of the digastricus muscle and ventral to the jugular processes of the occipital bone. At this point the common carotid artery terminates by giving off the occipital, and pharyngeal arteries and then further continues as the external carotid artery. Along its course through the neck, the common carotid artery gives out several branches as below.

The main arterial trunk that supplies blood to the hind limb is the external iliac artery. As this trunk passes down through different segments (regions) of the limb it is differently named according to that segment or the region. In the abdomen it is named as iliac, in the thigh region as femoral, in the leg region as tibial and popliteal and down that the metatarsal artery and lastly the digital.

External iliac artery

The external iliac artery arises from the abdominal aorta ventral to the fifth or sixth lumbar vertebra. It descends at the side of the pelvic inlet ventrally and caudally along the tendon of psoas minor, crosses the tendon, reaches the cranial border of the pubis, gains the space between the sartorius and pectineus muscles and then continues in the thigh (femoral region) as the femoral artery. In this course it is covered by peritoneum and is related laterally to the psoas minor, sartorius and iliacus muscles, medially to the common iliac vein and caudally to the external iliac vein. The following are the collateral branches of the external iliac artery.

The wall of the thorax and its contents (the viscera) are supplied by the following branches of the thoracic aorta.

Brachiocephalic trunk

The brachiocephalic trunk (Fig. 3-4 A) is a large vessel distributing arterial branches to the head, neck, thoracic limbs (fore limbs) and the cranial part of thorax especially to the region of the withers, thoracic floor and parts of the cranial third of the lateral thoracic wall. It arises from the convexity of the aortic arch between the right auricle and pulmonary artery within the pericardium. It is directed cranially and dorsally in the cranial mediastinum ventral to the trachea. It is partly covered on the right side by the cranial vena cava and on the left it is crossed by the vagus nerve. The recurrent laryngeal nerve runs between it and the trachea. It gives off the left subclavian artery opposite the second intercostal space or the third rib and the right subclavian artery opposite the first rib and then continues cranially as the common bicarotid trunk.

The subclavian arteries entirely furnish blood supply to the thoracic limbs. Except for different (separate) origins and the left artery being longer than the right artery, the right and left subclavian arteries are identical in their course and distribution. A short portion of each artery is within the thoracic cavity and is called as intrathoracic course. Each of these arteries leave the thorax by encircling and crossing the cranial border of the first rib below the insertion of the scalinus ventralis muscle and above the brachial vein. The intrathoracic branches of the subclavian arteries are the costocervical, caudal cervical and internal thoracic arteries.

A branch of anatomy that deals with joints or articulations in the body is termed as arthrology or syndesmology. A joint is an articulation or union formed by two or more bones or cartilages with the help of connective tissue. To form a joint, the long bones meet at their extremities e.g. joints of fore limb and hind limb. Joints of flat bones are formed by their borders or edges e.g. joint of bones of skull, the cranial and facial bones. The short bones and irregular bones form a joint by uniting at any of their parts or surfaces e.g. intervertebral joints.

Classification of joints

Joints are classified on the basis of their structure i.e. the kind of tissue material by which the bones are united, the other constituent parts that help in uniting the bones and the kind of movement performed at that joint. On this basis, the following three major types of joints exist in the skeleton of animal body.

Sacroiliac articulation

The sacroiliac articulation (Fig. 4-2 A) is a synovial (diorthroidal) joint formed between the articular surface on the wing of the sacrum and pelvic surface of the proximal extremity of the ilium. The articular area of the wing of the sacrum has a rough eminence while that of the ilium has a reciprocal rough depression. Both the articular areas are covered by a thin layer of cartilage. The joint cavity is a thin like a cleft and is crossed by fibrous bands.

The joint capsule is closely fitting around the margins of the articular surfaces. The joint capsule is reinforced by the ventral sacroiliac ligament which surrounds the joint. The dorsal part of this ligament is quite strong and it occupies the angle between the ilium and wing of the sacrum. The movements are inappreciable at this joint.

Shoulder joint

The shoulder joint (Fig. 5-2 A) is an enarthrosis formed between the glenoid cavity of scapula and head of humerus.

Ligaments: The shoulder joint is enclosed by the capsular ligament which is loose enough to accommodate the wide range of movements of the joint and is attached about 1.25 cm away from the periarticular area of the two segments of the joint. The capsular ligament is supported externally by the muscles of the shoulder region.

Movements: The shoulder joint performs all kinds of movements but the extension and flexion are best marked.

Most of the bones of the skull are joined (articulated) with the adjacent bones by sutures. These are immovable joints (synarthroses). The uniting medium is a fibrous tissue and is called the sutural ligament. Most of these joints exist in the early life of the animals and as the age of the animal advances the adjacent bones fuse with each other.

The articulations of hind limb (pelvic limb) comprises the joints of pelvic region which include the sacro-iliac articulation, pelvic symphysis and the hip joint; the articulation of thigh region named as stifle joint; the articulation of tarsal or hock joint and the articulations of digits which include the metatarso-phalangeal joint (fetlock) joint, the proximal interphalangeal joint (pastern joint) and the distal interphalangeal joint (coffin joint). The joints of pelvic region especially the sacro-iliac joint and the pelvic symphysis have been described with the articulations of abdomen and pelvis.

The articulations of the neck are between the bones of the cervical vertebrae. The atlanto occipital articulation and the atlanto axial articulation are the special vertebral articulations while the articulations between the rest of the cervical vertebrae are common vertebral articulations.

Atlanto-occipital articulation

Type of joint: This is a condyloid type of hinge joint (Ginglymus).

Articular surfaces: The atlanto-occipital joint (Figure 2-3 B) is formed between the condyles of the occipital bone and the condyloid cavities of the atlas vertebra.

Articulations of thoracic vertebrae

These are (1) Intercentral articulations which are amphiarthroses formed between the bodies of the adjacent vertebrae and (2) Inter neural articulations which are diarthroses formed between the articular processes of the vertebrae. These articulations are similar to the articulations described for typical vertebrae of the cervical region. The only difference is that the supraspinous ligament in the thoracic part of vertebral column is single as against two parts the funicular and lamellar parts of the cervical part of this ligament. The supra spinous ligament in the thoracic part is the backward continuation of the funicular division of its cervical part which extends medially behind from the occipital eminence , passes through the cervical region as nuchal ligament and continues behind over the summits of the spinous processes of the thoracic and lumbar vertebrae and finally terminates on the sacrum.

Introduction
Antimicrobial resistance (AMR) has emerged as a critical global health threat, diminishing the effectiveness of antibiotics against bacterial infections. Conventional strategies to counter AMR—including antibiotic stewardship programs and the development of new drugs—are often slow, expensive, and labor intensive. However, artificial intelligence (AI) and machine learning (ML) present ground breaking alternatives to address this challenge. By leveraging advanced computational techniques, AI can significantly speed up the discovery of novel antibiotics, enabling researchers to identify promising drug candidates more efficiently than traditional methods. Additionally, ML algorithms enhance treatment optimization by analyzing patient data to recommend personalized antibiotic regimens, reducing misuse and resistance risks. AI also strengthens surveillance systems by processing vast datasets— such as genomic sequences and electronic health records—to detect emerging resistance patterns in real time. These capabilities allow for proactive interventions, helping healthcare providers and policymakers stay ahead of AMR outbreaks. Together, AI and ML offer a transformative approach to mitigating AMR, combining speed, precision, and scalability to combat one of the most pressing medical challenges of our time.
AI in Antibiotic Discovery
One of the most promising applications of AI in AMR mitigation is in antibiotic discovery. Traditional drug development is costly and time-consuming, often taking over a decade [1]. Machine learning models can analyse vast datasets of chemical compounds to predict their antibacterial properties. For example, researchers at MIT used deep learning to identify halicin, a novel antibiotic effective against drug-resistant bacteria. AI-driven platforms can also repurpose existing drugs, reducing the time needed for clinical trials [2].
Fig. 1: AI cyclic interface in antibiotic discovery
Predictive Analytics for Resistance Patterns AI-powered predictive analytics enables early detection of antimicrobial resistance (AMR) patterns by processing clinical, genomic, and epidemiological data. Machine learning models analyse electronic health records (EHRs) [3] and bacterial genome sequences to identify emerging resistance threats in real time. These predictive insights allow hospitals to take proactive measures— such as optimizing antibiotic prescriptions—before resistant strains spread. Beyond clinical settings [4], AI models assist public health agencies in forecasting outbreaks and strategically deploying resources. By integrating large-scale datasets, these systems enhance surveillance, enabling faster, datadriven decisions to curb AMR progression. This approach not only improves patient outcomes but also supports global efforts in combating antibiotic resistance through smarter, pre-emptive interventions [5].

Climate change affects livestock through heat stress, water scarcity, unstable feed supplies, altered disease patterns and extreme weather. This chapter examines how artificial intelligence supports climate-smart and sustainable animal husbandry. Machine learning, predictive analytics and IoT-enabled monitoring can optimize feeding, detect disease, assess welfare and improve the use of water, energy and other resources. Intelligent technologies can also assist in reducing greenhouse-gas emissions and developing adaptive production strategies. The chapter evaluates the contribution of AI to productivity, climate resilience and environmental responsibility while addressing problems such as insufficient data, limited infrastructure, implementation costs and ethical concerns. Future integration with sustainable agricultural frameworks is also discussed.

Genetic improvement creates permanent, heritable gains in milk production, growth, fertility, disease resistance and environmental adaptation. This chapter explains how artificial intelligence complements conventional phenotypic and pedigree-based selection by analysing large genomic and performance datasets. Machine-learning models reveal genotype-phenotype relationships, predict breeding values and support earlier, more reliable selection. Applications include genomic selection, precision breeding, reproductive technologies, bioinformatics and digital twins. AI can reduce generation intervals and improve the efficiency of breeding programmes, but its success depends on data quality, representative populations and interpretable models. Ethical concerns, genetic diversity and long-term sustainability must also be considered when designing AI-supported breeding systems.

Genetic improvement creates permanent, heritable gains in milk production, growth, fertility, disease resistance and environmental adaptation. This chapter explains how artificial intelligence complements conventional phenotypic and pedigree-based selection by analysing large genomic and performance datasets. Machine-learning models reveal genotype-phenotype relationships, predict breeding values and support earlier, more reliable selection. Applications include genomic selection, precision breeding, reproductive technologies, bioinformatics and digital twins. AI can reduce generation intervals and improve the efficiency of breeding programmes, but its success depends on data quality, representative populations and interpretable models. Ethical concerns, genetic diversity and long-term sustainability must also be considered when designing AI-supported breeding systems.

Various indicators like range of behavioural, physiological, pathological and carcass-quality parameters can be used to assess the welfare of animals. Whenever, animals undergo painful handling or any other managerial operation, they are likely to face short-term stress. In this condition an increased physiological responses, behavioural responses, injury or mortality are most commonly used; however, some animals which are kept in improper housing with less floor space may cause chronic stress leading to increased disease incidence and suppression of normal development. Therefore, the following techniques can be used to assess the animal welfare at farm level in any given situation.

Abdominal part

The sympathetic trunks enter the abdominal cavity between the psoas minor and the crus of the diaphragm of the corresponding side. They run caudally on the ventrolateral surfaces of the lumbar vertebrae and the ventral common vertebral ligament. The left trunk is ventrally related to the abdominal aorta and the right trunk to the caudal vena cava. The sympathetic trunks of the opposite sides in the cranial half of the lumbar part lie rather close to each other and as they pass caudally, they gradually divert from each other. The lumbar sympathetic ganglia are small spindle shaped usually six in number and are present one in each lumbar segment. The first two are larger than the rests. Each is connected with the ventral division of the corresponding lumbar spinal nerve by the ramus communicans. The interganglionic segments of the sympathetic trunk are usually single but some times they split.

Splanchnic nerves

The greater (major) splanchnic nerve is formed by the contribution of sympathetic nerve fibres from fifth or sixth thoracic to thirteenth thoracic sympathetic ganglia. It becomes larger and larger as it passes caudally along with the sympathetic trunk. It enters the abdomen at the level of the first lumbar vertebra gets separated from it, passes ventrally and laterally across the aorta (left trunk) and vena cava (right trunk) to join the coeliacomesenteric autonomic plexus on and around the coeliac and cranial mesenteric arteries.

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.

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.

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.