eChapters

The escalating global demand for livestock products, driven by rapid population growth and rising per capita consumption, presents significant challenges for the agricultural sector (Moreau and Jordan, 2005). Traditional livestock production methods are becoming inadequate to meet this demand sustainably. Biotechnology offers novel solutions to enhance productivity, improve animal health, and ensure environmental sustainability (Schmitt and Henderson, 2005). This review aims to explore the role of biotechnology in livestock, focusing on key innovations and their implications for the future of animal agriculture.

1. Genetic Engineering

Genetic engineering has revolutionized the field of animal science by enabling precise modifications of the livestock genome to enhance desirable traits and reduce undesirable ones.

1.1 Transgenic Technology

A mouse was the first successful transgenic animal followed by pigs, sheep, cattle, and rabbits (Shakweer et al., 2023). Transgenic animals are created by inserting foreign genes that encode specific traits, such as growth hormone genes to enhance growth rates or disease resistance genes to reduce susceptibility to infections (Hammer et al., 1985). For instance, transgenic cattle have been engineered to produce milk with modified protein content (Zhang et al., 2019), improving its nutritional profile for human consumption (Brophy et al., 2003). Further, cattle genetically engineered to express human lysozyme in their milk have shown enhanced antimicrobial properties, making the milk safer for consumption (Moreau and Jordan, 2005). These modifications not only boost productivity but also improve the quality of livestock products, making them healthier and more nutritious.

Research techniques are the various methods and tactics strategically used to collect the materials, record the observations and analyse the data for study. These approaches provide a structured framework for achieving research objectives and validate the findings.

Anatomy is the oldest scientific discipline of the medicine, which deals with the form and structure of the organisms. The first documented scientific dissection on the human body were carried out as early as in the third century BC in Alexandria. At that time anatomists explored anatomy through dissection of animals, primarily on pigs and monkeys. The first written evidence of anatomical terms and rational observations can be found in the Egyptian medical papyri. The work of Andreas Vesalius played a significant role in medical research and education. During the 19th century the research in anatomy increased due to discovery of microscopes which allowed in-depth studies of body tissues and their components. However, in the last 100 years due to technological innovations and the growing understanding of related sciences progress in anatomy took place at a much faster pace. A thorough knowledge of research techniques in anatomy is very important to perform systemic experiments to reach a definite conclusion. The technique should be selected according to the aim and field of research. Here we are going to discuss some of the important gross anatomical techniques.

Forensic science has traditionally been associated with human criminal investigations, but its application to veterinary cases is gaining momentum. Hair is a specialized outgrowth of epidermis, a component of the skin. Hair is chemically stable especially when compared to other physiological materials such as blood, semen or any other f luid as it is strongly resistant to decomposition and this property makes hair a nearly ideal type for physical evidence. However, the forensic identification of animal hair requires different skill sets and competencies to those required for human hair comparisons (Tridico et al. 2014). Hair carry a lot of biological information, their examination is easy and very cost effective. Recently Funes et al. (2023) has reviewed both macro and micro quantitative methods for human hair analysis.

The study of the animal hair could represent a useful tool in veterinary forensic investigation and thus can be helpful in species identification in veterolegal cases, illegal transport of slaughtered animals, poaching or wildlife crime, fraud in textile and fur industry, traceability of predators and identification of their victims (Dahiya and Yadav 2013). The use of hair analysis in forensic science dates back to the 19th century, with early forensic scientists recognizing its potential in criminal investigations. Over time, techniques have evolved from simple visual comparisons to sophisticated microscopic and biochemical analyses.

A diverse microbial population colonizes the sterile mammalian gastrointestinal tract during and after the birth. This organized and long-lasting process of colonization by microorganisms has developed into flourishing relationships creating diverse environment within the host gut (Mazmanian et. al. 2005). There are various factors that affect the optimum colonization of gut microbiome and their normal functioning on various organ systems of the host body directly or indirectly. The gut microbiome comprises of a complex combination of microbes (Mezouar et. al. 2018). The mammalian gastro-intestinal tract harbors this complex ecosystem in equilibrium with the host immune system. The most magnificent feature of this commensal relationship is that the host not only tolerates but has also evolved to require colonization by commensal microorganisms for its own development and health. There are various factors that affect the optimum colonization of gut microbiome and their normal functioning on various organ systems of the host body directly or indirectly. The process of colonization is a two way interaction between the host and the microorganisms.

Introduction

Neuroanatomy research covers a wide range of topics including, gross anatomy of brain and spinal cord, imaging technologies for diagnosis, surgical anatomy, microscopic anatomy on nervous system, ultrastructural details on neurons and neuroglia, research on gene and protein expression patterns using in situ hybridization and immunocytochemistry. Despite many challenges, neuroanatomy in animals remains a crucial area of study for understanding the basic principles of structural organisation and its physiology. This review on the master glands i.e. hypothalamus and hypophysis cerebri, is mainly focused on the histomorphology and ultrastructural details reported in rat, rabbit, sheep, goat, buffalo and camel.

Mastering the Master gland

The hypothalamus (“hypo” meaning below, and “thalamos” meaning nuptial chamber / innermost room) is a major centre of the brain consists of regulatory circuits that controls internal body functions for survival. The hypothalamus is a small, central region of the brain composed of a conglomerate of hypothalamic nuclei and their nerve tracts. The hypothalamic neural connections to the pituitary glands in various mammals have been studied under light microscopic examination of sections of hypothalamus and pituitary gland together intact with infundibular stalk (Paramasivan et al., 2011). The nerve fibres of various hypothalamic nuclei coursed on as a distinct bundle into the infundibular stalk and then continued into the neurohypophysis. Through its connections with pituitary gland, the hypothalamus exerts an enormous influence over the endocrine system and thereby over the general metabolic functions and reproduction (Clemente, 1985). The pituitary gland (hypophysis cerebri) is considered as the master endocrine gland as it plays a critical role in influencing and controlling the activities of other endocrine glands viz. thyroid, adrenal, ovary, testis and pineal. However, the hypophysis itself is under the control of the hypothalamus which actually masters the endocrine function of various hormones released from the master gland i.e. hypophysis cerebri.

In the 19th century, Etienne Geoffroy de Saint Hilaire conducted pioneering studies on prenatal anomalies such as cyclocephaly, anencephaly, and twin monsters, and is credited with coining the term 'teratology'. The physician Josef Warkany is considered the father of experimental teratology. His studies led to the definition of both genetic and environmentally induced structural defects. The occurrence of congenital malformations varies significantly across species, breeds, and geographic locations. Studies suggest that approximately 1.5% to 6% of live-born domestic mammals exhibit recognizable congenital malformations. These malformations range from complex anatomical abnormalities to complicated enzyme defects detectable only through advanced molecular diagnostics. Occurrence of these malformation is very low in cat while in sheep, cattle and horses it is almost 3-4 % and highest in dogs and pigs and is range about 6%. The genesis of congenital malformations is understood as interplay between an embryo's genetic makeup and its developmental environment. Teratology thus highlights the critical periods during embryonic development when external influences can significantly impact normal growth and formation, underscoring the delicate balance between genetic predisposition and environmental factors in shaping fetal development. Teratogens are those substances which may cause inheritable birth defect via a toxic effect on an embryo or foetus. These defects include malformation, disruption, deformation and dysplasia which may cause stunted growth, congenital disorders that lack structural malformation. A fundamental principle of teratology is that the susceptibility to teratogenic agents those causing malformations vary with the embryo's developmental stage at the time of exposure. Exposure during the first three weeks of gestation (stage of preformation), when the basic body plan is established, typically results in early embryonic death or is compensated for by regulatory mechanisms within the embryo. Agents that disrupt the morula or blastocyst stages, or interfere with embryo maternal communication and proper implantation in the uterine mucosa, often lead to early embryonic mortality. The severity of malformation is depends on the frequency and dose of the teratogens. Most of the teratogens affect the embryo during early differentiation and organogenesis stage. It has been found that the organogenesis of urogenital system of bovines, equine, canines, porcine and felines are most susceptible for teratogenic agents.

Introduction

Lymphatic tissue in general consists of reticulin fibres and fixed cells (macrophages and reticulin cells), as well as free cells (lymphocytes, plasma cells and granulocytes). In loose lymphatic tissue, fixed cells predominate whereas, in dense lymphatic tissue, free cells predominate. The stem cells which colonize the embryonic thymus and bursa originate in the area pellucida or embryo proper in birds. Late in embryonic development, stem cells may be found in the liver and spleen. In adult life they exist primarily in the bone marrow. The avian lymphatic system is divided into:

A. Primary lymphatic tissue (central): Primary lymphoid organs in birds include the thymus and the bursa of Fabricius, which are the places where lymphocytes develop, and the T-cell and B-cell receptor genes rearrange. The avian primary lymphoid organs, the thymus and the bursa of Fabricius, undergo age-dependent changes leading in some cases to the complete atrophy of the organ. Interestingly, the bursa of Fabricius can act as both i.e. primary and secondary lymphoid organ. Primary lymphatic tissue is antigen dependant, and in it incoming stem cells differentiate into immunologically competent B and T cells, which then migrate to the secondary lymphatic tissue

B. Secondary lymphatic tissue (peripheral): It consists of the spleen, gut-associated lymphoid tissue (GALT), including the caecal tonsil, lymph nodes, bone marrow, mural lymphoid nodules and variable aggregations of lymphocytes throughout the body. Secondary lymphatic tissue is antigen dependent "effector" tissue, in which B and T cells mature into respective effector cells.

Introduction Adaptations in animals and birds are countless and extensive, which permit the species better suited in its environment and thus improve chances of survival and propagative success. There are three major categories of adaptations namely anatomical/structural, physiological and behavioural adaptations. Depending on the animal habitats, adaptations can be classified into terrestrial, aquatic and volant (flying). Terrestrial adaptations are exhibited by the organisms inhabiting in land habitats and are again grouped into cursorial, fossorial, arboreal and desert adaptations.

Terrestrial Adaptations

1. Cursorial Adaptations

Cursorial animals are those adapted for running over long distances, often characterized by adaptations that enhance speed and endurance. These adaptations include various skeletal features that optimize their locomotion and overall efficiency while running. These animals have streamlined and spindle-shaped body to minimize resistance in attaining the speed. Here are the key skeletal adaptations in cursorial mammals:

1. Long and Slender Limbs: Cursorial mammals typically have long and slender limbs, which reduce the amount of energy required per stride and increase stride length, thereby enhancing running speed. Lengthening of the limbs in these animals leads to the head placed away from the ground. Hence, as an adaptation to feeding and drinking, the neck and the skull become elongated.

2. Reduced Number of Toes: Many cursorial mammals have reduced the number of toes to streamline the foot and reduce weight. For example, horses typically have a single functional toe (hoof), while cheetahs have reduced and non-retractable claws.

Introduction

A deep knowledge of veterinary anatomy is essential for more sustainable livestock management practices, enhancing productivity while minimizing environmental impact. Understanding the physiological structure and function of food-producing animals enables professionals to make informed decisions regarding production, meat processing, and food safety. In today's modern workforce, a comprehensive grasp of animal anatomy is essential for success in various fields, including agriculture, veterinary science, food processing, and quality control. Professionals can enhance their expertise, make data-driven decisions, and drive innovation in the food production sector by grasping animal anatomy. Ultimately, this foundational knowledge is vital for advancing careers and ensuring the highest standards of quality, efficiency, and safety in the industry. Meat processing professionals require in-depth knowledge of animal anatomy to guarantee optimal carcass handling, accurate meat quality evaluation, and streamlined production workflows. Expertise in animal anatomy is also crucial for food safety and quality control specialists, enabling them to ensure regulatory compliance and maintain consumer trust. Additionally, knowledge of animal anatomy allows these specialists to identify potential contaminants and implement effective control measures. By possessing a thorough understanding of animal anatomy, industry professionals can optimize efficiency, quality, and safety throughout the meat processing and distribution chain.

Introduction

Veterinary Anatomy is regarded as the firm foundation and the knowledge gained in the subject is the basis for reasoning and helping with the diagnosis and treatment of animals. Teaching gross anatomy is highly regarded as being clinically relevant. The research on a wide range of species in Veterinary anatomy will be helping to be the understanding of their biology. The research conducted helps to understand the anatomy of domestic and wild animals and how this can be applied to diagnostic imaging and other disciplines of Veterinary Science. Hence teaching and research in anatomy provides foundation on which the knowledge of clinical practice and medicine is built. The research in Anatomy pave way for advanced research in other Veterinary Discipline.

TEACHING PERSPECTIVES

Anatomy education has entered newer and more innovative methods of teaching. “Vesalius” referred to as a founder of modern Anatomy struggled to make dissection of cadavers mandatory in 16th century and its significance is again being questioned today in search of substitutes. Hence use of alternatives to dissected specimens and multimedia teaching methodologies to teach anatomy and basic principles of Veterinary Medicine and Veterinary Surgery have gradually become more popular.

Formalin, traditionally used for preserving anatomical specimens in veterinary education, poses well-documented hazards like toxicity and carcinogenicity. This proposal advocates for adopting safer, innovative preservation methods that maintain anatomical integrity and meet modern educational and ethical standards. The study aims to evaluate various formalin-free preservation methods: plastination, cryopreservation, resin embedding, and 3D scanning and printing. Plastination involves fixing specimens in 10% formalin, dehydrating in acetone, impregnating in glycerine, and curing in corn starch. Cryopreservation rapidly freezes tissues in liquid nitrogen, all chemical reactions, and biological processes are suspended. Resin embedding encapsulates specimens in epoxy resin, and advanced imaging creates detailed, interactive 3D models. Plastination maintains anatomical integrity and durability better than traditional formalin, retaining original structures with minimal distortion, and providing long-lasting educational resources. Cryopreservation preserves tissue well but requires specific storage conditions. Resin embedding produces clear, durable specimens but is less flexible for handling. 3D printing offers highly detailed, interactive models without chemical exposure risks. All methods avoid formalin’s toxic properties enhancing safety for students and educators. Transitioning to formalin-free preservation methods improves health and safety by eliminating toxic exposure and enhances educational value with more interactive and detailed models. These methods promote sustainability and align with modern ethical standards. Advanced imaging supports contemporary education by providing precise, manipulatable anatomical representations in a virtual environment. Adopting innovative preservation methods such as plastination, cryopreservation, resin embedding, and advanced imaging technologies ensures safer, high-quality anatomical education aligned with modern standards of Veterinary anatomy education.

The current study focused to investigate the significance of AgNOR count in diagnosis of canine mammary tumour and its correlation with histopathological evaluation. A total of 53 cases suspected for canine mammary tumour were presented to Veterinary Clinical Complex, DUVASU Mathura from January 2021 to April 2022, out of these 42 cases were screened as neoplastic while 11 were non- neoplastic based on cytological examination. 24 tissue samples were collected out of 42 neoplastic cases during surgical procedure under general anaesthesia for further detailed examination by the approval of Institutional Animal Ethics Committee vide application number IAEC/22/22. AgNOR staining revealed that carcinoma solid had highest number of AgNOR followed by malignant myoepithelioma and fibrosarcoma. AgNOR count gives an assessment of cell kinetics and is directly related to proliferative activity of cells.

Globally the field of veterinary is dominated by women as 55% of veterinarians are women. In India 76% girl graduates were in the year 2021. Lady Veterinarians have been successful at their jobs especially in recent years. This brings out whether there is a psychological relation to this. “Animals are good companions for women.”, said Sreeja Arangottukara to The Hindu.[1] Gender is an identity which develops in a child around the age of 2 or 3 which is influenced by socialisation, culture, and biology.(Penn State College of Liberal Studies)[2] Various psychological researches have shown that women and men differ in intensity of certain attributes. From the ages of 21-64 years assessed with Rytt’s Psychological Well Being Scales and Bem Sex Role Inventory conducted under general Spanish population of 1700 men and 1700 women.(National Library of Medicine) It was found that women were better in positive relations which helps in developing trust between the veterinary team and clients and achieving a positive public perception of the veterinary profession.(today’s veterinary practices)[3] Women are better at understanding facial and body cues which lead them to understand the requirement of the client/patient in medicinal branch of veterinary. Moreover, women are better at verbal skills too their memory and analysing ability makes them capable of research and advancement in the field of animal husbandry. In a profession like veterinary women have better psychological ability and resultingly better at their job.

Antimicrobial resistance (AMR) includes antimicrobial use and abuse in human, animal and environmental sectors. It also covers the spread of resistant bacteria and resistance determinants within and between these sectors and as global phenomenon. Most of the classes of antimicrobials used to treat bacterial infections in humans are also used in animals. Major concerns in the animal health are treatment of animals with antimicrobials that are critically important for humans too, such as third-generation cephalosporins and fluoroquinolones. Another important issue is the use of medically important antimicrobials in feed for long term, such as colistin, tetracyclines, and macrolides, for growth promotion. Inappropriate use and unprofessional choice of antibiotics without performing antibiotic susceptibility test in animals results into higher occurrence of antimicrobial resistance. Given the important and interdependent human, animal and environmental dimensions of AMR, it is logical to take a One Health approach when addressing this problem. One Health is the multidisciplinary, collaborative, scientific and coordinated approach to address health threat at human, animal and environment interface, the aim of One Health approach is to understanding and designing interventions and policies to combat AMR. WHO recently has launched new guidelines on the use of medically important antimicrobials in food-producing animals, recommending that farmers and the food industry stop using antimicrobials routinely to promote growth and prevent disease in healthy animals. Thus these guidelines will help to preserve the effectiveness of antimicrobials that are important for human medicine by reducing their use in animals.

A study was conducted to assess utilization pattern of ICT based Information by the livestock owners in using information communication technology with special reference to enhanced livestock production, in Mathura district of Uttar Pradesh. A total of 80 farmers were selected for study. The results showed that cent percent of the farmers had availability and accessibility of mobile phones as well as television. Majority of the livestock farmers are regularly using ICT tools for information dissemination. Majority (85.00%) of respondents were saying scientific information of livestock is available on mobile followed by (25.00%) of respondents said this scientific information are available on computer. Apart from these (68.75%) of respondent usage of mobile as ICTs tools for getting health related information of animals. Mobile phone was the most frequently and widely used while radio was least used ICT tool among the livestock farmers being used for the purpose of getting information.

Ruminant, major source of meat and milk for human consumption, whose digestive system has evolved in such a way that it provides an additional advantage of being non-competitive to human food chain. Global warming is real and rising with a pace threatening lives of all flora and fauna on earth. Methane produced by ruminant bacteria predominately by methanogen group of bacteria acting as hydrogen sink cause loss of dietary energy to the animal affecting its potential productivity as well as a major source of global warming. The use of plant secondary metabolites is preferred as a feed additive in ruminant diet to improve fatty acid production by reducing enteric methane. The study was carried out using 10% aqueous and ethanolic extract of Psidiumguajawa leaves powder, citrus fruit peel powder to assess in vitro rumen fermentation parameters. The in vitro trial was conducted by taking different concentrations @ 0.2 ml, 0.5ml, 1ml and 2 ml of plant extracts with substrate media containing rumen fluid. After 6 and 24 hours of incubation, pH, total gas production, ammonia- nitrogen, TVFA and total nitrogen were measured. Bacteroides and methanogenic bacterial profile was done by Real time PCR. The results revealed that the total gas production decreased in plant extract supplemented samples with respect to control. Total nitrogen production increased in aqueous P. guajawa and increase in TVFA was observed in all plant extract supplemented samples. Ammonia- nitrogen production does not vary significantly, indicating no change in NPN degradation due to supplementation of different plant extracts at different concentration. Total bacteroides expression were increased in rumen samples treated with P. guajawa and citrus peel powder, while a decrease in methanogenic bacterial expression was observed in plant extracts supplemented samples as compared to control indicating an improvement in rumen fermentation further enhancing productivity.

Bovine leukocyte adhesion deficiency (BLAD) is a lethal autosomal recessive disease caused by a point mutation in CD 18 gene. Through Minimum Standard Protocol (MSP), Government of India made mandatory to screen all the breeding and newly introduced HF bulls for this BLAD. In this present study screening for mutation is carried out by polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP). Non availability of positive control made us to resort for synthesis of DNA probes with similar sequence of the gene with mutation and authenticity was verified by nucleotide sequencing. A total of 200 blood samples collected from phenotypically normal HF bulls from organized farms and subjected to PCR-RFLP technique. The results indicate that out of 200 bulls, 01 bull (0.5%) was found to be carrier for mutated gene CD18. Hence it is mandatory to screen each bull to prevent accidental transmission of mutant gene to a large number of future populations.

The present study was conducted on 36 adult dogs of six different breeds in order to standardize normal ocular parameters. Six breed specific groups of dogs were Group 1 (German Shepherd), Group 2 (Pug), Group 3 (Spitz), Group 4 (Labrador Retriever), Group 5 (Rottweiler) and Group 6 (Non-descript) with 6 animals (3 males and 3 females) each. STT values revealed non-significant difference between sex and eyes. Among groups only Pug breed showed significant difference with GSD breed. Intraocular pressure reflected a non-significant difference between sex and eyes. IOP values of Labrador group were within the normal range but differ significantly from Pug and Non-descript groups. B mode ultrasonography revealed internal structures with various echogenicity. In B mode ultrasonographic biometry a significant difference in all parameters was observed among groups except ODL and OND. Longest and shortest axial globe length was revealed in Labrador and Spitz, respectively. Overall mean for sex revealed a longer vitreous chamber depth, axial globe length and optic disc length in males as compared to females. Non-significant difference was observed in all the parameters between left and right eyes. Standardized breed specific ophthalmic parameters were useful in diagnosing various ophthalmic affections, viz. keratoconjunctivitissicca, glaucoma, cataract, retinal detachment etc. in clinical cases.

Introduction

The compassionate treatment of animals and consideration for their well-being is an important aspect of livestock farming. Compassions needs to be an integral part of livestock farming as livestock are sentient being. Positive human experiences during handling are essential for ensuring the welfare of animals. Humans play a significant role in the environment of production animals, particularly in commercial cattle production where daily interaction occurs. Intensively farmed animals endure negative emotions that diminish their welfare. For instance, they experience fear from unfamiliar stimuli or from being separated from their social group (Jones, 2011), as well as stress, pain and frustration due to the obstruction of naturally driven behaviors (Dawkins 1998) or the absence of predictability and control over their surroundings (Bassett et al, 2007), along with boredom stemming from insufficient environmental stimulation (Wemelsfelder, 1993). Compassion is a fundamental virtue in veterinary practice, and female-owned businesses in this sector often exhibit this attitude. Compassion, the highest quality of women, is highly valued in veterinary practice, and women-owned enterprises are perfect example of this. They place a high value on compassionate care, acknowledging the close bond between people and animals and making sure each animal gets the attention and assistance they require by focusing on improving the quality of life for all animals and their loving owners.

A novel zoonotic disease was reported in December 2019 in Wuhan (China) and patients were presumably exposed to a new coronavirus, designated as SARS CoV-2. This virus probably crossed into humans from an animal species, most likely a bat, spreading rapidly across the world and causing the coronavirus disease 2019 (COVID-19). This infectious illness was responsible for a global pandemic that caused deaths and economic despair (Santaniello et al., 2023). The latest WHO data (December 2023) confirmed 77,38,19,856 cases worldwide since the beginning of this zoonosis and 70,10,568 deaths (WHO, 2023), making this pandemic one of the deadliest in human history. Human CoVs (HCoVs) are often of animal origin but adapt to humans via direct jumping or through intermediate species. These data and the zoonotic origin of SARS-CoV-2 quickly raised questions concerning the potential role that animals could play in transmitting the virus to humans or other species.

Introduction

In recent years, women have made remarkable strides in the veterinary field, bringing a wealth of skill and dedication to various sectors, including clinical practice, research, academia, and industry. Today, women comprise a significant portion of the veterinary workforce. However, the path to leadership and career advancement still presents unique challenges. Gender biases, limited representation in senior roles, and the constant balancing act between personal and professional life often stand in the way. As a woman in this field, I understand the significance of leadership development and the impact it has on creating a meaningful, rewarding career. This session aims to equip women veterinarians with actionable strategies and essential leadership skills to advance their careers meaningfully. Leadership is not merely a title; it’s about creating positive change, setting examples, and inspiring those around us. For women in veterinary medicine, it means breaking barriers, making a difference, and contributing to animal welfare and public health. By cultivating confidence and a focused approach, women can rise to leadership roles that truly make an impact.

Introduction

Milk, which is recognized for its significant nutritional and immunological value to humans as well as animals, is the primary source of vital nutrients and bioactive components that contribute to the newborn’s growth and development. In addition, it includes extracellular vesicles (EVs). EVs are membrane-bound vesicles that are discharged by cells into biofluids like milk. EVs play an important function in intercellular communication and have demonstrated potential in therapeutic applications. This is extremely important since EVs are abundant in milk and carry a wide range of cargo, including proteins, lipids, and nucleic acids, that supports to their classification as bioactive components of milk Milk-derived exosomes have intriguing properties as nanocarriers for theranostic care.

Introduction

Biofilm formation is a series of complex process and accomplished mainly in five stages -Reversibleattachment, Irreversible attachment or colonization,Proliferation, Maturation &Dispersion. Usually biofilms comprise 10% of dry mass that represent microorganisms while the rest 90%derived from the matrix of biofilm. Microbial biofilms are aggregates of microorganisms embedded in self-produced matrices and adhere to an abiotic or biotic surface. Firstly, Marshall et al. (1971) threw light on the concept of biofilms &it’s complexity was discussed by many researchers. According to Donlan and Costerton (2002) “Biofilm as a structured community of microbial cells enclosed in a self-produced polymeric matrix and adherent to a surface to interface, and to each other” still remains the most appreciated definition of biofilms (Mishra et al., 2022). Basically, microbial biofilms are complex, dynamic and three dimensional heterogeneous structures in which cells are interconnected by EPS (Extracellular Polymeric Substances). Biofilms are found to be resistant against UV light, metal toxicity, antimicrobials and other chemical agents like soaps, detergents, disinfectant and other cleaning agents. Future insight the immense need to implicate effective methods for elimination of biofilms from the environment.

Introduction

Diagnosis of cancer has always been challenging. There is no single diagnostic test to confirm the cancer. A detailed evaluation of the patient comprises of history, physical examination and various diagnostic tests.

Most common steps in the diagnosis involve physical examination, imaging tests, laboratory tests, biopsy etc. Other than these there are several other battery of tests that are followed in modern diagnostics. The main aim of the diagnosis is to determine what type of cancer and more importantly the stage and the grade. Early detection of cancer provides cure or better chances of survival in any patient. It improves the prognosis of cancer and potentiate the effect of targeted therapy. There are several moderndiagnostic techniques like 2D and 3D imaging using PET positron emission tomography, MRI, Computed Tomography (CT), X Rayimaging and ultrasound scanning. The diagnosis of tumor involves several steps.

Introduction

My journey into the heart of wildlife conservation began in the unassuming classrooms of KendriyaVidyalaya, where my curiosity for the natural world was nurtured by dedicated teachers and an enriching curriculum. My dreams took f light when I studied stories of Mahadevi Verma in my school days where she was taking care of wild animals in her home. Fuelled by my determination, I pursued my education in Veterinary College, Hebbal, Bangalore from 2006 to 2011. To increase my knowledge and help the wild animals in better way, I did master in Veterinary Microbiology from Veterinary College, Hebbal, Bangalore during 2012-2014, research was conducted in “Salmonellosis in Wild Animals” and PG diploma course in wild animal disease management from TANVAS, Chennai in 2016 research was on “Oral Microflora of Snakes”. Pursing higher studies gave direction to help wild animal, also gave me abilities to write research paper which will help the communities.

Introduction

Goat farming plays a significant role in supporting rural livelihoods, contributing to food security, and generating income through milk, meat, and fiber production. However, achieving sustainable goat productivity requires scientific management, wherein, nutrition is a critical factor that makes profound effect on overall performance and production. With increasing global demand for goat-derived products, optimizing nutritional strategies has become essential to improve both production efficiency and sustainability. Globally, the sector is shifting from subsistence-oriented backyard farming to more commercialized systems, driven by increasing demand for goat meat and dairy products. India, which ranks first in goat population with 148.88 million goats (DADF, 2019), is experiencing rapid changes as goat farming evolves from a low-input livelihood strategy into a thriving commercial industry (Ramachandran et al., 2019).This transformation is not only economic but also ecological. Goats are known for their remarkable adaptability to harsh environments and climate variability, which makes them crucial in ensuring food security under changing environmental conditions. Their ability to utilize marginal lands and convert low-quality forages into meat, milk, and fiber allows them to thrive in regions unsuitable for other livestock . Shifting towards semi-intensive and intensive systems, farmers can utilize better breeding, nutrition, and healthcare practices to meet growing market demands.

Introduction

In current scenario of COVID-19 pandemic, Agriculture and its allied sectorare the only sector which is contributed positive growth rate due to hard work and total devotion of farmers towards it in both first quarter of the financial year 2022-23. Farmers are the backbone of our country but face different challenges such as scarcity of land due to fragmentation, water sources, impassable roads, unavailability of better financial services and new technologies. Since a decade number of small and marginal farmers keeps on increasing. Due to the fragmented holding of land and improper management practices in farming inadequate access to market, making them agriculture more unviable. Government motive to double the farmers’ income in 2022-23 by addressing the challenges of farm sector. The government affirmed that farmer producer organizations (FPO) are the most appropriate institutional form around which farmers can mobilize and build their capacity to collectively leverage their production and marketing strength. However, majority of these located in rural areas and suffer from the problems like Inadequate Professional Management and Manpower, poor start-up capital, lack of technically skilled man power, ineffective capacity building training programmes. There is a need to find the solution and to need bring policy changes to handle this problem to empower our farmers and Indian economy by farmers produce organisation.

Introduction

India is primarily an agriculture-based country, with the livestock sector being a vital component of its agricultural landscape. The meat sector plays a crucial role in providing livelihoods and jobs to rural and village populations. Slaughtering food animals not only yields meat but also generates valuable byproducts that can significantly benefit society. Typically, only one-third of an animal’s weight is meat; the remaining two-thirds consist of byproducts and waste, which must be effectively processed and utilized. Efficient utilization of these byproducts directly impacts both the economy and environmental pollution. The yield of animal byproducts can range from 50% to 60% of an animal’s live weight. According to statistics from the Department of Animal Husbandry and Dairying (DAHD, 2019), India saw the slaughter of 11.92 million buffalo, 3.05 million cattle, 50.86 million sheep, 97.19 million goats, 10.73 million pigs, and over 2.81 million poultry birds in 2018-19, resulting in the production of 8.11 million tonnes of meat.

Introduction

As per 20th Livestock Census, 2019 goat population in the country was 148.8 million, the second largest species in terms of number after cattle. Uttar Pradesh, one of India’s largest states in terms of population and agricultural activity, boasts a substantial goat population of 14.48 million, which accounts for approximately 9.73% of the country’s total goat population. Goats indeed play a crucial role in many agrarian economies worldwide, including India. In regions where crop and dairy farming may not be as economically viable, goats provide a valuable source of income and sustenance for small and marginal farmers as well as landless laborers. Goats, specifically Capra hircus, possess unique qualities that make them valuable assets in meeting this growing demand for animal protein (Rout et al. 2018). The livestock market has been experiencing significant growth, with global trade presenting vast opportunities for livestock farmers to increase their income. One notable trend over the past decade has been the increasing preference for animal protein consumption worldwide. This shift in dietary habits has led to a surge in demand for meat products, particularly in developing countries where access to protein-rich foods may be limited. The adaptability, diversity, and versatility of goats make them an invaluable resource for agriculture and livelihoods in both developed and developing nations, contributing to food security and economic sustainability in many regions (Mazhangaraet al. 2019).

Introduction

Podocytes are highly specialized cells with a complex structure that plays an important role in kidney physiology. The characteristic feature of these cells is that its cell body has foot processes which interdigitates with the foot processes of another podocytes leaving filtration slits in between them. These filtration slits are bridged by the slit diaphragm which is an extracellular structure. These cells are located on the outer surface of glomerular basement membrane (GBM) and thereby they check the protein loss. The cell body of these cells contain nucleus, golgi apparatus, smooth and rough endoplasmic reticulum, lysosome and mitochondria. Their main function is in establishing the selective permeability of the glomerular f iltration barrier. Several molecules, including nephrin, CD2AP, FAT, ZO-1, P-cadherin, Podocin, and Neph 1-3 have all been shown to be associated with the slit diaphragm (SD) protein complex, and some of these molecules are critical for its integrity. In cases of chronic disease podocytes gets loosen and they separate from the surface of glomerular basement membrane (GBM). Podocyte injury frequently leads to reorganization of the slit diaphragm and reorganization of the foot process structure. Disturbances of podocyte architecture results in retraction of its foot processes which leads to proteinuria. This may be thelater progress into acquired glomerular diseases. The approach to regenerate podocyte and develop a mechanism of podocyte specific drug delivery system by understanding the molecular mechanism of podocyte function appears a promising area for treatment of proteinuric kidney diseases in future.

Introduction

It is estimated that zoonotic infections account for around 60% of infectious diseases and 70% of newly developing infections in humans. The major zoonotic illnesses that have outbreaks documented between 2009 and 2023 have been divided into two categories: endemic and emergent (IDSP). Zoonoses that are either newly discovered in a population or that have been known to exist in the past but are rapidly expanding in frequency or geographic range are referred to be emerging zoonotic diseases.A variety of underlying causative variables contribute to the genesis of zoonotic illnesses, which pose a worldwide risk to the health of both humans and animals. They reduce food availability, impede agricultural output, and contribute in unnecessary trade embargos. Livestock is crucial to the livelihoods of impoverished farmers, consumers, and traders in India. Close relationships between human population groups and animals, the consumption of unpasteurized milk and dairy products, the intensification of animal production andincreased trade in animals and animal products, the high number of stray animals, illegal slaughter, and improper waste disposal are major risk factors in the introduction and sustenance of zoonotic infections. These outbreaks are continuously increasing. More and more such episodes of new zoonoses such as Nipah virus disease, Crimean Congo Hemorrhagic Fever (CCHF), Kyasanoor Forest Disease (KFD), Dengue, Chikungunya, Japanese encephalitis, and Zika virus disease have been reported between 2014 and 2023 as compared to the period between2009and 2013.

Introduction

To maintain optimum reproductive status early diagnosis of reproductive problems is important. Various advance diagnostic techniques are available for diagnosis of reproductive problems. Some of them are still in early stages of development or some though available; are not widely used due to various constrains.The various diagnostic techniques used in animal reproduction are ultrasonography, Doppler ultrasonography, endoscopy, laparoscopy, hormonal assays, vaginal cytology, x ray etc.

Accurate history and Thorough examination of reproductive tract

Accurate history is a powerful tool of enormous clinical value. Behavioral problems due to pain or psychological factors can also be ruled out on the basis of adequate history of the patient. Tentative differential diagnosis can be made by taking history of previous breedings.Through digital and vaginiscopic exanimation of reproductive tract helps to rule out anatomical abnormalities, which may interfere with natural mating. It also helps in diagnosis of fertile phase of oestrus cycle. In cases of refusal to mate due to anatomical problems like septum, narrow passage or due to behavioral problems AI can be performed. Vaginoscopic examination aids vaginal cytology in deciding right time of natural service or insemination in proper breeding management or abnormal oestrus cycle.

Introduction

The peripartum period, spanning from 3 weeks pre-calving to 3 weeks post calving, is a critical phase in a cow’s life. During this time, cows are susceptible to various diseases that can significantly impact their health, productivity and reproductive performance. Changes in metabolism and lack of optimum immunity have been closely associated with most of the transition period diseases. Hormonal changes in the early lactation results in drain in energy and nutrients rendering the animal in some degree of negative energy balance. Increased lipid mobilization in transition period has its role in fatty liver and ketosis directly.Metabolic stress in peripartum cows refers to the physiological changes that occur around calving, affecting energy and nutrient balance.

Introduction

Status of Tuberculosis : Tuberculosis is a complex and multispecies disease since the origin of human civilization. Evidence of tuberculosis (TB) exists in 3000 years old Egyptian mummies and about 17,000 year old fossilized bison (Fareed et al., 2024). Now, every year, 10 million people fall ill with tuberculosis. Out of 10 million people currently with new active TB, 1,40,000 (range, 69,800–235,000) are estimated to be new cases of zTB (1.4%) of which an approximately 11,400 (8.1%, range 4,470-21,600) died (WHO, 2020).Despite being a preventable and curable disease, 1.5 million people die from TB each year – making it the world’s top infectious killer (WHO, 2023). Disease is still in an increasing scenario as evident that in 2018, an estimated 10 million people fell ill with TB and 1.5 million died of the disease whereas in 2021 there were an estimated 10.6 million new cases of TB and 1.6 million TB deaths (Ayalew et al., 2023). COVID-19 has further increased the projection of TB and increased the expected case number. As it is predicted that between 2020-2050, 31.8 million will have died of TB, More than half million cases of TB annually are classified as drug resistant, as a result, TB is becoming more difficult to diagnose and treat.

Introduction

In poultry, the intestine is home to trillions of microorganisms, with bacterial concentrations reaching up to 10¹² bacteria per gram of digesta. In a healthy digestive system, this microbial community is highly diverse and metabolically active, supporting crucial functions in digestion, immune defense, and overall health. The gastrointestinal tract (GIT) of a newly hatched chick begins as a sterile environment but quickly develops a complex microbiota as the bird matures. The composition of gut microbiota is highly variable, shaped by environmental factors, diet, the genetic makeup of the host, and other influences. This dynamic microbiome plays a pivotal role in nutrient absorption, disease resistance, and growth efficiency, making it a central focus in poultry health management and productivity enhancement.The health and productivity of poultry are fundamentally influenced by the gut microbiome, which shapes digestion, immunity, and growth potential. Microbial diversity variesacross several poultry species, including broilers raised intensively, native chickens in free-range conditions, and unique species such as Guinea fowl, Kadaknath, and red jungle fowl. Using advanced metagenomicsanalysis of microbial diversity, structure, and function, highlighting the implications of microbiota composition on poultry health and productivity possible. The gut microbiota is increasingly recognized as a major determinant of health and productivity in poultry. It not only influences nutrient absorption and metabolism but also plays a critical role in immune response and pathogen resistance. Intensive farming practices have altered gut microbial ecosystems in commercial broilers, often reducing diversity compared to native breeds and heritage species raised in field conditions.

Introduction

Climate change specifies long-term shifts in weather patterns, which are measured over decades to millions of years. In modern times, it predominantly concerns the increase in Earth’s average temperature due to human activities, particularly the burning of fossil fuels10. The rise in greenhouse gases such as carbon dioxide, methane, and nitrous oxide traps heat in the atmosphere, leading to global warming. In connection with animal health, climate change affects the ecosystems in which animals live, influencing the availability of water and food, the spread of diseases, and the physiological stress animals endure due to temperature extremes. Domestic animals, mostly livestock, are vulnerable to heat stress and reduced productivity, whereas wildlife faces altered habitats and increased exposure to pathogens. The connection between climate change and animal health is intricate, as changes in temperature, humidity, and weather patterns create new challenges for both domestic and wild species.

Introduction

In modern poultry farming, the need for alternatives to probiotics is increasing due to concerns about the stability, viability, and potential side effects of using live microbes. Postbiotics have emerged as promising substitutes, offering similar health benefits without the risks. Postbiotics are non-viable microbial metabolitewhich exhibit benefits like promoting gut health, boosting immunity, and preventinfections, which are crucial for sustainable poultry production. Postbiotics enhance gut health by modulating immune responses, improve the microbialenvironment,and inhibit pathogenic growth. Furthermore, their incorporation can reduce theneed for antibiotics in poultry farming, contributingto a decrease in antimicrobial resistance. With the growing global population and increasing demand for animal protein, postbiotics offer sustainable solutions. The review concludes that postbiotics could revolutionize poultry farming, aligning with global efforts toward food security and the achievement of the United Nations Sustainable Development Goals, particularly Goal 2 i.e. Zero Hunger. Future research should focus on optimizing these additives for large-scale commercial use.This paper highlights the concepts of postbiotics, their mechanisms of action, current research advances, beneficial effects in poultry farming, and future prospects.

Introduction

The classic bone tissue engineering paradigm highlights several key players: biocompatible scaffold that closely mimics the natural bone extracellular matrix niche, osteogenic cells to lay down the bone tissue matrix, morphogenic signals that help to direct the cells to the phenotypically desirable type, and sufficient vascularization to meet the growing tissue nutrient supply and clearance needs. The biomaterials are critical components in the bone-tissue engineering strategies, including polymers, ceramics, or their combinations applied in various forms, such as membranes and three-dimensional (3D) scaffolds. These materials typically mimic the extracellular matrix of bone tissue during the tissue regeneration process, providing mechanical support and a suitable environment for cell attachment, proliferation, and differentiation

Introduction

Parvoviruses are nonenveloped, single-stranded DNA viruses belonging to the genus Protoparvovirus, member of the Parvoviridae family, that has been included within the species Carnivore protoparvovirus 1, together with Feline panleukopenia virus (FPV), Mink enteritis virus (MEV) and Raccoon parvovirus (RPV), according to the International Committee on Taxonomy of Viruses (Tijssenet al 2011). Two distinct parvoviruses are known to infect dogs—the pathogenic CPV 2 and CPV-1 or the minute virus of canine (MVC). CPV-2, the causative agent of acute hemorrhagic enteritis and myocarditis in dogs, is one of the most important pathogenic viruses with high morbidity (100%) and frequent mortality up to 10% in adult dogs and 91% in pups. CPV-2 is the etiologic agent of a contagious disease, mainly characterized by clinical gastroenteritis signs in younger dogs. This virus that causes the disease “parvo”, first emerged among dogs in Europe around 1976. By 1978 the virus had spread unchecked, causing a worldwide epidemic of myocarditis and inflammation in the intestines (gastroenteritis) and could infect domestic dogs, spreading in the global dog population within 2 years. This original type, was rapidly replaced by two antigenic variants, types 2a and 2b (Parrish et al 1985, 1991), and in 2000 a third type CPV-2c was detected (Buonavogliaet al 2001). Canine parvovirus (CPV) is responsible for acute gastroenteritis in pups, with a high rate of mortality (Carmichael and Binn, 1981). We now know the virus is not limited to dogs, but is capable of causing infections in wild canines such as coyotes and wolves, and other wild animals, including foxes, raccoons and skunks. Since its emergence in 1978, it was and remains a common and important cause of morbidity and mortality in young dogs.

Introduction

The preservation of animal specimens for museums is a critical practice in natural history, enabling education, research, and conservation awareness. Traditionally, specimens are often sourced from zoological facilities or specific conservation programs. However, the innovative use of fallen animals—animals that have died of natural causes or accidents—presents a sustainable and ethical method of specimen preparation. India has large livestock population. As per 20th livestock census in the country, livestock sector of India comprised of 303 million bovines (Cattle, Buffalo, Mithun and Yak), 74.26 million sheep, 148.88 million goats, 9.06 million pigs and about 851.81 million poultry. Each year large number of livestock is lost due to natural disaster such as flood, cyclones, draughts avalanches, landslides, snowstorm and forest fire. Approximately 55% of its buffalo, 38% of its cattle, 41% of its goats and 47% of its pigs are vulnerable to floods which regularly destroy farmlands. On the other hand, 44% of country’s livestock are affected by draught. Cyclones also causes huge loss to the livestock as well as to the wildlife. According to Down to Earth magazine and Centre for Science and Environment approximately 92519 livestock were killed in India in 2023 due to extreme weather including cyclones.

Introduction

“Invest in Women: Accelerate Progress” -the theme of the International Women’s Day 2024 celebrated by the United Nations and multiple organizations across the world highlighted the need of review of different works and efforts in bringing gender equality in various development departmentsincluding agriculture and allied sectors. This reflects the importance being given to the efforts towards gender equality at the highest level.

Agrifood systems are a major employer of women globally and constitute a more important source of livelihood for women than for men in many countries. Empowering women and closing gender gaps in agrifood systems thus, enhances the well-being of women and their households, reducing hunger, boosting incomes and strengthening resilience.Increasing women’s empowerment is essential for women’s well-being and has a positive impact on agricultural production, food security, diets and child nutrition. Also,the gender-transformative approaches to change restrictive social norms are cost effective and have high returns, but morework is needed on developing pathways to implement gender-transformative approaches.

Introduction

Emerging and reemerging infectiousdiseases are defined as the diseases of which the incidence has shown an increasing trend in the recent past or threatening to increase in the near future. Emerging infectious disease (EID) are caused by apathogen previously unknown to cause disease orre-emerging pathogens, which have previously causeddisease but now reveal increased infectivity orextended transmission ranges that improve their ability to cause disease in human populations. Today, whole world is facing a concerning rise in emerging infectious diseases and the majority of EID have been observed in the past decades.Multiple recent EID outbreaks e.g. the 2003 SARS and the 2012 MERS outbreaks, the 2009 swine flu pandemic,the 2013–2016 Ebolavirus epidemic, the 2014chikungunya outbreak in the Western Hemisphere,the 2015 Zika and the 2019 SARS Cov 2 virus epidemic have exhibited significantmorbidity and mortality and large geographicranges. These outbreakshave indicated the potential for evenmore severe outcomes in future outbreaks. Severaladditional pathogens are also considered capable ofproducing EID outbreaks, these include Escherichia coliO157:H7, hantavirus, dengue virus and West Nilevirus, while malaria, tuberculosis (TB), cholera, andinfluenza are often considered reemerging diseases with the potential for new outbreaks.Many newly emerging diseases in humans are actually long-standing zoonosesof animal host species that appeared inhuman populations following a climatic or environmental change. The complex interplay between climate change, ecosystems, and human activities have created conditions that favour the emergence and spread of infectious diseases posing significant challenges to public health. Although, improved sanitation, increased access to health care, and advances in preventive and clinical medicine have reduced the mortality and morbidity rates of several infectious diseases.

Introduction

The gut microbiota is the complex and dynamic community of microorganisms that includes various bacteria, fungi and other microorganisms, proliferate and lead a symbiotic/mutual relationship with the host system. These microorganisms protect the host against pathogens by unique mechanisms, helps to maintain shape and strengthen the intestinal epithelium and boost immune response. Diverse bacterial metabolites can immigrate the host bloodstream and other parts of the body via various channels in humans and animals, such as gut-microbiota-brain, gut microbiota-skin, gut-vagina, gut liver, gut-bones etc. However, many aspects of modern lifestyle would alter the gut microbiota and lead to numerous diseases including inflammatory bowel disease, diabetes mellitus, obesity, and metabolic syndrome. Probiotics and other beneficial microbes exert many beneficial effects on their hosts by modulating the gut microbiota. While the term probiotic is reserved only for well-characterised strains with clinically proven health benefits, other beneficial microorganisms include, organisms responsible for the fermentation of foods viz. yogurt, kefir, kombucha, kimchi and many others that have been shown to have distinct health benefits. Interestingly, major group of these beneficial organisms belong to lactic acid bacteria.

Introduction

Lactic acid bacteria (LAB) are characterized as Gram-positive cocci or rods, non-aerobic but aerotolerant, able to ferment carbohydrates for production of energy and lactic acid. Lactic acid bacteria includes different major genera: Lactococcus, Enterococcus, Lactosphaera, euconostoc, Melissococcus, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella. Other genera are Aerococcus, Microbacterium, Propionibacterium and Bifidobacterium. Through carbohydrate fermentation along with lactic acid, various organic acids are produced due to which there is a fall in pH level and creates unfavorable environment or inhibits growth of some undesired microorganisms. The low pH makes organic acids lipo -soluble, allowing them to invade into cytoplasm of pathogens by rupturing cell membrane. LAB are generally regarded as safe (GRAS), and have a significant role in the preservation of foods and fermented products. Under controlled conditions they can be used as natural competitive microbiota or as specific starter cultures. Antagonistic substance like bacteriocins are produced from lactic acid bacteria that inhibits the activity and growth of other bacteria and these bacteriocins are active against various pathogens in minimum concentration. These are antimicrobial peptides modified by post -translational mechanisms and exported to the extracellular medium. Till date about 239 bacteriocin producing LAB genome and 789 putative bacteriocin producing genes cluster are stored in the public databases. Many gram positive and gram negative bacteria in the environment produce bacteriocins.

Introduction

Let food be thy medicine and medicine be thy food- the age-old quote by Hippocrates, is certainly the tenet of today. Microbial cultures have been used for millenniums in food and alcoholic fermentations and in the past century have undergone scientific scrutiny for their ability to prevent and cure a variety of diseases. Later it became popular in improving human and farm animal nutritive values and recently in aquaculture also. The growing interest in the understanding the role of food in human health has moved from its primary role as a source of energy to the subtle action of biologically active food components on human health. Henceforth functional foods or nutraceuticals are of great demand in present time. The growing scientific evidence suggests that the food supplements containing beneficial bacteria can provide an array of benefits to the host. Now a day’s probiotic fermented foods are in great demand due to the awareness of beneficial aspects of probiotics among people. Several industries focused on the improvement of conventional fermented foods scientifically in order to fetch good market for their products. Particularly, animal feed companies and researchers have been looking for alternative products and strategies that can help to maintain animal gut health in order to prevent or reduce the prevalence of pathogens in the food chain. After understanding the mechanism and beneficial aspects of probiotics in detail at molecular level in earlier chapters, now it is relevant to discuss the applied part of probiotics. In this chapter, commercial importance of probiotics and probiotics derived products at industrial level are emphasized.

Diversity of gut microbial community

The human microbiota (the collection of microbes that live on and inside us) consists of about 100 trillion microbial cells that outnumber our ‘‘human’’ cells 10 to 1, and that provide a wide range of metabolic functions that we lack. It has been estimated that they encode 100-fold more unique genes than our own genome. Furthermore, the gut microbes contribute to energy harvest from food, and changes of gut microbiome may be associated with bowel diseases or obesity. To understand and exploit the impact of the gut microbes on human health and well-being it is necessary to decipher the content, diversity and functioning of the microbial gut community. If we consider ourselves as superior organisms encompassing these microbial symbionts, by far the majority of genes in the system are microbial. In this sense, completing the human genome also requires the characterization of the microbiome (the collection of genes in the microbiota).

Methods of counting viable and non-viable bacteria in gut

Before the advent of genome sequencing and genome-wide analysis method, our knowledge of molecular characteristics of diverse gut microbial population was extremely limited. To obtain an estimate of cultivability, microbial ecologists generally compare microscopic counts with total viable counts. The total viable count made on a nonselective agar based medium estimates the number of colony forming units (cfu) per gram of sample. The finding that total viable counts are typically lower than total microscopic counts was thought to be due to the number of dead cells. Indeed, dead bacteria in feces may constitute up to one third of the total bacterial community. However, recent nucleic acid based studies indicated that a majority of bacteria in a variety of ecosystems are different from those described in culture.

Introduction

It became clear from the discussions of previous chapters that probiotics perform metabolic functions such as fermenting indigestible dietary residues and endogenous mucus, production of vitamins, and absorption of minerals. They also play key role in intestinal epithelial cell proliferation and differentiation, and the homeostasis of the immune system. Further, probiotics are also known to involve in modifying gut pH, antagonizing pathogens through the production of antimicrobial compounds, competing with pathogens for recept or sites as well as for available nutrients and growth factors, stimulating immunomodulatory cells of the host, and produce a wide range of enzymes such as lactase, amylase, lipase, protease, phytase and so on. The molecular mechanisms of probiotics are largely unknown and opens avenue for research in probiotics. Moreover, current research in probiotics and health consciousness in the public lead to an increased interest towards probiotics from the public, researchers, governmental organizations (such as the WHO/FAO) and medicine and food companies. In this chapter, application of probiotics in treating various diseases and disorders are discussed.

Introduction

Cell surface components such as adhesins, polysaccharides, and proteins play major roles in the adherence of probiotic bacteria to the intestinal epithelium, interactions that might lead to pathogen exclusion and immunomodulation of host cells. Probiotic bacteria have the ability to produce exocellular polymers called Exopolysachcharides (EPSs). These exocellular polymers present in the surface of many lactic acid bacteria, including Lactobacilli.The adhesive properties of lactobacilli are directly linked to their surface properties which are influenced by the structure and composition of their cell wall. The cell envelope of lactobacilli, bacteria, is composed of the bilipidic plasma membrane with embedded proteins encompassed by the cell wall. The bacterial cell wall consists of a thick multilayered sacculus made of peptidoglycan (PG) with teichoic acids (wall teichoic acids (WTA) and/or lipoteichoic acids (LTA)), exopolysaccharides (EPS), proteinaceous filaments called pili, and proteins that are anchored to the cell wall through different mechanisms (Figure 1).

Some species of lactobacilli possess an additional paracrystalline layer of proteins surrounding the PG layer, referred to as the S layer. These macromolecules together may play crucial roles in determining species and strain-specific characteristics of lactobacilli by influencing host-microbe interactions and microbial adaptations to the changing host environment. Several studies implicate that cell surface components, either individually or collectively, involve in host-microbe interactions. Lactobacilli beneficially affect the host in many ways by producing abundant variety of EPSs through the activity of extracellular glycosyl transferases. Approximately 30 species of lactobacilli are described as EPS producers. Among them, the best known are L. casei, L. acidophilus, L.brevis, L. curvatus, L. delbrueckii bulgaricus, L. helveticus, L. rhamnosus, L. plantarum, L. johnsonii, etc.

Introduction

Preceding chapters discuss the essentials of probiotics, their role in maintaining gut health in combination with prebiotics and significance of systematic classification of probiotic isolates. Further, to draw an idea how probiotics function in the gut, it is essential to know the interaction of probiotics with other microorganisms in the gastrointestinal milieu - the site of their probiotic action. Knowledge in the ecology of probiotic microorganisms in host environment such as gut gives an ideal picture of their functioning manner and the factors (both host and microbial) responsible for it.

Study of microbial ecology in the gastrointestinal tract is very difficult since gut harbors highly diversified microflora that varies not only at species level but also at individual level. The diversity of gut microflora in two healthy individuals of same species may exhibit variations in their composition and it may be influenced by geodemographic factors also. In this regard, the present chapter deals with the study of ecology of Lactobacillus- most commonly used probiotic bacteria in the gastrointestinal tract which in turn helps in framing selection criteria for screening of potential probiotics.

Recent studies on interaction between human and gut microflora discussed that co-evolution between microorganisms and their host have contributed for the development of a very complex microbial diversity in the gut. Highly diversified microflora in the human gut is a consequence of natural selection at two levels, top-down and bottom-up selection pressure. Hierarchy theory expounds that higher levels compel lower levels for possible organizational solutions i. e. organisms at the higher levels govern the structure or population dynamics of an ecosystem while on contrary lower levels control the structure of ecology when bottom-up level is the selection pressure. In case of interaction between human and gut microflora, being host human is at higher level in the hierarchy for selection and as mentioned above, top down selection pressure is driven by higher levels; host selects the beneficial microorganisms for functional redundancy leading to the development of a microbial community with divergent microbial divisions. Chances for lateral gene transfer also thought to influence the selection process and there by structure of the microbial community. On the other hand, competition among the members of host selected microbiota exert bottom up selection pressure resulting in the development of highly specialized genomes with functionally prominent set of genes. Natural selection at host level obviously favors functionally constant microbial communities which benefits the host with functional redundancy encoded in their genomes. Mean while bottom-up cell-level selection pressure aspire to favor niche specialization to avoid competition between the members of microbial community. In order to be a part of specialized niche, to become more potent microorganisms adapt a particular set of abiotic and biotic factors within the habitat by acquiring new sets of genes essential for their survival and thus escape the competition from decrepit microbial species.

Introduction

From earlier chapters, it is evident that Lactobacilli and Bifidobacteria are the two important genera that have potent applications in food microbiology and human nutrition due to their role in food and feed production, preservation and also due to probiotic potentialities. Most of the bacterial species are still unknown indicating that the identification and classification of bacteria is a hard task since the beginning of microbiology and consequently our knowledge about bacterial ecology is very low. Mean while the expectations about novel bacterial products are high. Therefore, bacterial identification has become a growing field of interest in microbiology. Since, Lactobacilli and Bifidobacteria genera include a large number of species and strains exhibiting important properties in an applied context, chiefly in the area of probiotics as food and therapeutics, an updated list of species belonging to these two genera, their phylogenetic relationships and other relevant taxonomic information are of great significance. The classification and identification of a probiotic isolate at strain level point out its typical habitat and origin. Moreover, the species, or genus name, may also indicates the strain’s safety and technical applicability for its use in probiotic products. Taxonomy helps to place a newly identified organism in a relevant group and enables the scientific communication. Further it facilitates the construction of databases that can be used for rapid identification of organisms at laboratory level easily. Thus, taxonomy of Lactobacilli and Bifidobacteria helps to study these organisms scientifically and allows characterizing and arranging them in an orderly manner which promote the scientific community to explore the benefits from those organisms for the betterment of mankind.