eChapters

Introduction

Global plastic production is on rise while the production in 1950 was 1.3 million tonnes wherein 359 million tons of plastic waste generation was recorded in 2018. It is predicted that the increase in plastic waste generation will reach around 250 million metric tonnes by 2050 (Haque and Fan, 2022). Plastics are now ubiquitous and has turn out to be the most dominant marine litter, which is an emerging global concern today. According to the UNEP, United Nations Environment Assembly 2017 estimates, annually around 4.8 12.7 million metric tonnes of plastics are introduced into the oceans (Haward, 2018). Owing to their lower costs, lightweight, durability and strength, virtually everything and everywhere are plastics.

Introduction

Fisheries management is the scientific approach that is heavily influenced by ecosystem theory but primarily focuses on fishing activity. In inland waters, it expanded from wildlife management and involved direct intervention in habitat and species composition. (Lackey, 1999) In marine ecosystems, management strategies focus on controlling fishing while using indicators for ecosystem and resource status. It is an integrated process concerned with collecting information, inspecting, organizing, decision-making, resource allocation, and regulation enforcement. Its goal is to sustainably utilize fishery resources for human livelihood, food, and recreation.

Introduction

In shrimp farming practice, the production cost of shrimps mainly depends on the feed cost and its associated water quality management issues. Hence, the success of shrimp aquaculture is wholly depends on the feed input cost and this feed cost involved can be reduced to a greater extent by enhancing the organic productivity of the ponds, particularly by enhancing the plankton productivity, which include, the assemblages of phytoplankton and zooplankton.

Introduction

Water pollution is a significant issue that damages the quality of aquatic ecosystem. The pollution of water bodies is caused by several point and non point sources. Among them, wastewater released from livestock farms poses a potent risk for environmental pollution accelerating disease load and premature deaths (Vaishnav et al. 2023). Numerous small and large scale livestock farms are being operated around world to compensate the increased food demand from about 200 kcal per person per day in 2000 to about 400 kcal per person per day in 2050, South Asia's food demand for livestock products is expected to almost double (Thornton, 2010). Significant dietary changes toward animal based foods accelerates the livestock production (Springmann et al. 2016).

Introduction

Aquaculture is one of the rapidly growing industries worldwide with more than 300 different species being cultured. However, majority of aquaculture species are still wild and undomesticated, and the adaption of relevant technologies in the aquaculture sector has been slow. Given that genetically modified stock only accounts for less than 10% of the current global aquaculture production, the aquaculture sector has significant potential to increase production efficiency through selective breeding programmes. Selective breeding is acknowledged as a crucial element in the generation of resource-efficient, sustainable, and profitable aquaculture operations (FAO, 1995; World bank, 2006).

Introduction

Aquaculture uses a variety of chemicals for a number of functions, including sediment and water management, improving natural aquatic productivity, transporting living organisms, creating feed, manipulating and enhancing reproduction, promoting growth and health, processing, and adding value to the finished product (GESAMP, 1989). Aquatic systems are thought tobe suitable places to recycle and dispose of hazardous and sewage wastes, with any excess being drained into the ocean. To fulfil the demands of the ever-increasing population, the water resources are overused for potable supplies, irrigation, industry, and thermal generating plants, which drastically diminishes their assimilative capacity.

Introduction

Genetic markers are genes or DNA sequences associated with a specific gene or trait, often arising from mutations or alterations in genomic loci (Samarai and Kazaz, 2015). Recently, there has been a growing interest in molecular markers, which reveal polymorphisms at the DNA level. These markers play a crucial role in animal genetics studies, as they help identify genetic resources and differences between domesticated and wild animals. Cytological markers, which use chromosome karyotypes, bandings, repeats, translocations, deletions, and inversions, are widely used for elucidating species origin and classification (Becak et al., 1971; Jonker et al., 1982).

Introduction

In recent years, inland saline aquaculture has emerged as a rapidly growing sector in the broader field of aquaculture due to the escalating pressure on traditional freshwater resources and the escalating demand for seafood. Saline aquaculture, cultivating aquatic species in inland waters with elevated salinity levels, presents opportunities and challenges. This chapter examines the innovations and challenges that characterize inland saline aquaculture, highlighting the urgent need for sustainable approaches that balance productivity with environmental resilience. The global population growth and dietary preferences have caused an increase in the demand for seafood (FAO, 2020).

Introduction

Aquaculture is the fastest growing food producing sector. According to FAO (2016), Aquaculture is the farming of aquatic organisms including fish, crustaceans, mollusks, and aquatic plants in all types of environments including ponds, lakes, oceans, and rivers. Aquatic resources have played an essential role in ensuring food security by supplying the enormous demand for animal protein. Around 17% of animal protein consumed by people worldwide comes from fish (Shah and Mraz, 2020). Fish provide the highest quality protein sources, essential amino acids, fatty, vitamins, and minerals which are lacking in others (Kwasek et al., 2020). The world population will exceed 9 billion by 2040. Therefore, to feed a rapidly increasing population, aquaculture production must increase globally

Introduction Concerns about how future generations can sustainably produce more food are felt everywhere. The use of chemicals, nutrient leaching, and the conversion of natural land to agriculture are all important problems that have a negative influence on the environment and natural resources. The usage of nitrogen in artificial fertilizers has increased 20 times over the past 20 years, severely eutrophicating water bodies. Therefore, it is believed that the only approach to increase water and nutrient efficiency, as well as reduce waste, is to close the loop between crops and animals. A further step towards sustainability would be to use less land (Datta, 2016).

An understanding of normal values of electrocardiographic indices of healthy dogs and cats is utmost necessary for interpreting an abnormal electrocardiogram. The criteria for normal configuration and measurements of the waves, segments and intervals in an electrocardiogram of healthy subjects provides basis for detecting abnormalities in the electrocardiogram of the ailing animals. The electrocardiogram, like other diagnostic aids, is not an absolute indicator of health and disease and therefore it is required to be interpreted in conjunction with patient’s history, clinical manifestations, and the results of other investigations.

After successful recording of the electrocardiogram, the next step is its reading, analysis, interpretation and report writing. It is the most important part of electrocardiography. Patients details ( name, species of animal, breed, age ,sex, owners’ name and address with E-mail and mobile number) and date of tracing are to be mentioned in the electrocardiograph prior to actual recording of the electrocardiogram or can be jotted down on the ECG strip after completion of recording as per available facility in the electrocardiographic machine. Clinical complaints and observations should be kept in mind while interpreting the electrocardiogram.

This chapter on electrocardiograms for self-exercise is designed to provide opportunities to the readers to assess their understanding of reading and interpreting electrocardiograms and to increase their confidence. Each electrocardiogram has its detail and a question to answer. On the reverse side of each electrocardiographic tracing, detailed reading and interpretation is provided to match your assessment and to improve your interpretation skill. It is to be remembered that each electrocardiogram should be evaluated in conjunction with complete data base (history, clinical manifestations, laboratory investigations, radiological observations, and echocardiographic observations).

Though the treatment for arrhythmias has been recommended for even a single premature beat, in the current scenario the treatment is indicated when there are more than 17 VPCs per minute. In certain situations the side effects or proarrhythmic effects of drugs can lead to morbidity or mortality. As a result, new guidelines are proposed when evaluating the need for treatment of arrhythmias. Keeping the adverse effects of antiarrhythmic agents in mind, one should be selective about which arrhythmias are to be treated. The goal of antiarrhythmic therapy includes the treatment of an existing arrhythmia or prophylaxis for anticipated arrhythmias.

The word “arrhythmia” has been derived from ancient Greek ?ρρυθμος (arruthmos) via new Latin “arrhythmia”. Arruthmos is made up of ‘a ‘(without) and ‘rruthmos’ (rhythm) means without rhythm. By definition as per dictionary, arrhythmia is defined as any disturbance in the rhythm of the heartbeat. In fact in medical sense arrhythmias are the disturbances not only in cardiac rhythm but also in cardiac rate or both. The seat of generating impulse in the heart is the pacemaker, of highest automaticity, in the SA node. If any impulse is generated outside the SA node pacemaker it leads to arrhythmias.

Apart from the heart rate and rhythm, the electrocardiogram also provides information pertaining to the chamber size, i.e. the presence of chamber enlargement in dogs. It can more precisely be evaluated if the P QRS and T complexes are clearly visible without any artifacts. Further, the measurement of the chamber enlargements is only possible when all the segments of the ECG are clearly visible. When the impulse is conducted uninterruptedly from sino-atrial node (SA node) to AV node to the ventricles, the measurement of the amplitude of the complexes (P, QRS, T) is more precise in providing information regarding the presence of chamber enlargement.

Departure of waves ( P,Q,R,S, T), segments (P-R, S-T and T-P) and /or intervals (P-R, Q-T, R-R) from their normal values (configuration, morphology, amplitude and duration of wave; prolonging /shortening of intervals : elevation /depression of segments from their isoelectric line) is said to be abnormal feature of the electrocardiogram. These abnormalities are suggestive of specific cardiac abnormalities such as a defect in the current generation, its conduction or both; or change in the size of the chambers (atria / ventricles/both.).

Electrocardiogram is a visual record of electrical activities going on in the heart during depolarization and repolarization (cardiac cycle). It is one of the simplest and fasted non-invasive diagnostic test available to evaluate cardiac function. Though the heart of large mammals have many similarities, difference in shape, size, positioning in thoracic cavity and innervation of Purkinje f ibers exists in different species of the animals making the electrocardiogram peculiar for that species of animal. Peculiar characteristics that distinguish the electrocardiograms of different species of animals are given in this chapter.

Electrocardiogram (ECG)

Electrocardiogram is a graphic record of electrical events of the heart recorded by the electrocardiograph. It represents the sum up surface voltage and direction of electrical activity produced during cardiac muscle depolarization and repolarization plotted against time (Fig. 33). The time is represented on the X- axis (horizontal line) and amplitude of voltage is represented on the Y-axis (vertical line) of the graph. The potential difference occurring over the surface of the body (at different lead placement locations) is associated with depolarization and repolarization of heart muscle (myocardium). The amplitude of the potential difference is measured as milli volt (mV) and their duration is measured in second or milliseconds.

The process of recording an electrocardiogram involves preparation of sites, application of conduction gel, positioning and restraining the patient, attaching the electrodes and then actual recording. Errors in placement of electrodes and artifacts during electrocardiography may generate erroneous electrocardiogram.

Sites for Placement of Electrodes in Dogs and Cats

There are definite sites (Fig. 15 and Fig.16) for placement of electrodes both in dogs and cats .Improper placement of electrode may lead to erroneous electrocardiogram.