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The foundation of modern insect classification was laid by Brauer in 1885. According to Brauer insects were classified as Subclass: Apterygogenea (pterous) and Pterygogenea (winged) based on:

• Presence or absence of wings.

• Mouthparts.

• Metamorphosis.

• Number of Malpighian tubules.

• The nature of wings.

• Thoracic segments etc.

The earliest classification of insects was based on habits and habitats and on certain gross anatomical features that define the general aspects of different kinds. In classifying insects, not only anatomical characters but also facts pertaining to physiology, biology, distribution, ecology and sometime cytology of the species is taken into consideration.

Classification

Classification is ordering of organisms into groups (or sets) on the basis of their relationships that are of associations by contiguity, similarity or both.

Classification of living things is an attempt to interpret nature. It attempts to bring together the kinds that are alike and closely related and to separate those that are unlike and unrelated.

Animals might be classified in various ways but the classification is based primarily on structural characters. Those animals with certain structures in common are classified into one group, and those with other structures into other group. Thus the animal kingdom is divided into a dozen or so major groups called phyla (singular, phylum); each phylum has a name, and its members have certain structural characters in common. The characters used to distinguish phyla include the number of cells, symmetry, body form and segmentation, the nature of the appendages, and the arrangement of the internal organs.

On the basis of degree of complexity, and probably evolutionary sequence, the animal phyla are usually arranged in a series from the lower phyla to the higher ones.

Nomenclature should not be confused with terminology which deals with terms, like antenna, abdomen, radius etc. Names of animal and plants may be either vernacular or scientific.

Vernacular names or local names of plants and animals are different from region to region, from language to language.

Scientific names or Latin or International names are used universally all over the world. Without them we would not be able to communicate and to use the knowledge accumulated about animals and plants in literature. These international names are under certain rules or nomenclature.

Nomenclature

No-men-cla-ture means a system of names. It is derived from Latin Nomen means name and calor means to call, which means to call by names. Nomenclature is the “language of Zoology” and the rules of nomenclature are its grammar. Since all zoologists work with animals and used their names, it is essential that the general principles of zoological nomenclature be familiar to all zoologists.

Origin of Insects

Insects are highly specialized group of invertebrates belonging to the largest animal Phyla, the ARTHROPODA, which also includes in it, the prawns, crabs, lobsters, centipedes, millipedes, scorpions, ticks, mites and spiders. Practically three fourth of the animal species come under this phylum.

The Arthropods evolved during Cambrian period from primitive annelidan ancestor. The main evolutionary stem of Arthropod is represented by the Crustacia- Insecta- Myriapoda.

The insects originated in the Devonian period of Palaeozoic era. Diplura and Thysanura are the most primitive wingless insects while mayflies, damselflies, dragonflies and stoneflies represent the primitive winged insects.

Evolution

Evolution is a process whereby population are altered over a period of time and may split into separate branches, hybridize together or terminate by extinction.

Arthropods occur up to the height of over 6,080 meters on land and up to the depth of about 59,728 meters in water. Different arthropod species are adapted for living in air, on land, in soil and in fresh, brackish or salt water.

Many insects are economically important for being pests of crops, stored grains, stored food, household goods and clothing etc. Some insects and arachnids are in one way or the other responsible for certain diseases of crops, domestic animals and human beings. Some arthropods, on the other hand, such as crabs, lobsters, prawns and shrimps form a part of human diet while, small sized crustaceans are staple food for fishes. Many parts of the world have witnessed some insects and spiders eaten by many land animals including man.

Insects share many characters with other arthropods, but the other arthropods have not been able to exploit these to the extent insects have evolved. The presence of functional wings is a very important character which insects do not share with other arthropods, that is why insects have distinct advantage over other arthropods in their struggle for existence and dominance. A comparative account of Insecta and other arthropod classes is given in Table 1.

Origin of Systematics

In Vedas (1500 BC), Ramayana (1900 BC), Mahabharata (1400 BC), and Upanishad (350 BC) mention had been made about various animals. The number of known species of animals is much greater than that of plants and has been estimated at about more than one million. When subspecies are included, the number may double to more than two million named forms of animals. The new animals are being described at the rate of about 10,000 per year. Metcalf (1940) estimated that one and a half million species names are already applied while Silvestre (1929) calculates an estimated 3 million probable species of insects.

Systematics

Systematics is a term coined by a Swedish naturalist Linnaeus (Systema Naturae 1735) which is a Latinized Greek word Systema, as applied to the systems of classification. According to Simpson, “Systematics is the scientific study of the kinds and diversity of organisms and any or all relationships among them.” It includes Taxonomy, identification, classification and nomenclature. Now-a-days, both terms are used inter-changeably in the fields of plant and animal classification.

Arthropod life began very early in Palaeozoic region, about 600 million years ago in the sea. The arthropod foundations were laid with the evolution of metamerism in segmented worms, and in the ancestral arthropods it resembled the now extinct Trilobites. They had harder cuticle forming the exoskeleton and a pair of jointed legs with each of its metameric segments.

The Trilobite stock soon diversified into:

a) Chelicerates.

b) Mandibulates.

a) Chelicerates: In Chelicerates, the anterior body segments fused to form the prosoma, bearing a pair of chelicerae, the feeding organs; a pair of pedipalps and four pairs of walking legs. The remaining segments formed the legless opisthosoma. This gave rise to Eurypterids (Extinct) Xiphosurians, Pycnogonids and the highly successful Arachnids, including the scorpions, spiders, ticks and mites.

1. Jefferies SR. 2014. Bioactive and biomimetic restorative materials: a comprehensive review. Part I. J Esthet Restor Dent. 26(1):14-26.

2. Sharma M, Murray PE, Sharma D, Parmar K, Gupta S, Goyal P. 2013. Modern approaches to use bioactive materials and molecules in medical and dental treatments. Int J Curr.Microbiol. App. Sci., 2(11):429-39.

3. Laskin Daniel M: Oral and Maxillofacial Surgery vol 1

4. Kay C. Dee, David A. Puleo, Bizios R. 2002. An Introduction to Tissue Biomaterial Interactions.

5. Peltola MJ, Vallittu PK, Vuorinen V, Aho AA, Puntala A, Aitasalo KM. 2012. Novel composite implant in craniofacial bone reconstruction. Eur Arch Otorhinolaryngol. 269(2):623-8

6. Kao ST, Scott DD. 2007. A review of bone substitutes. Oral Maxillofac Surg Clin North Am. 19(4):513-21, vi.

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The craniofacial region presents a unique challenge for implantable biomaterials because the pull of the craniofacial muscles produces variable loading in different regions. In addition, craniofacial skin loses elasticity with the age and develops subcutaneous tissue sags.

Even though surgeons are familiar with the use autogenous bone grafts for craniofacial reconstruction, the usage of alloplastic bone substitutes has increased continuously, because autogenous bone is difficult to harvest, time consuming, causes significant donor morbidity, and bone resorption, but most important thing is that the biocompatibility of current alloplastic materials are improving.

Synthetic substitute creates a new avenue for clinicians to explore as adjunct in surgical procedures. These materials may not necessarily be used solely for reconstructive procedures, but when used in the right situation in combination with autologous, allograft or other synthetic, the result have the potential for more desirable results.

In the past, there was no targeted development of biomaterial based on scientific criteria. Instead devices consisting of material that had been designed, synthesized and fabricated for various industrial needs (the textile, aerospace, and defense industries) were tested in a trial and error fashion in the bodies of humans and animals. These unplanned and sporadic attempts had modest success. Most frequently, the results were unpredictable, mixed, and confounding both in success and in failure. In addition to traditional medical devices, diagnostic products, pharmaceutical preparations and healthcare disposables, now the list of biomaterial application includes smart delivery systems for drugs, tissue cultures, engineered tissues and hybrid organs. Undoubtedly biomaterial have had major impact on the practice of contemporary medicine and patient care in both saving and improving the quality of lives of the humans and animals4.

Biomimetics is defined as the study of the formation, structure, or function of biologically produced substances and materials and biological mechanisms and processes especially to synthesize similar products by artificial mechanisms which mimic natural ones.

Biomimetic materials and molecules have been applied in many of the potential research areas in medical and dental sciences and highlight their foundation from plants, animals, or microbes that can be used to treat human disease.

A bioactive/biomimetic material and biocompatible material is an artificial or natural material used to change part of the living system or to function in internal contact with living tissue. Bioactive materials can interact with living tissues or systems.

There are several types of biomimetic materials like

Osteogenic Materials

Osteoconductive Materials

The term “artificial intelligence” (AI) refers to a wide variety of theories and technologies that are used to the resolution of issues characterized by a high level of logical or algorithmic complexity. It cuts across a wide range of f ields, such as mechanical modeling, software engineering, data science, and statistics. Many artificial intelligence (AI) technologies, which first appeared in the 1950s, have lately been refined or extended thanks to advances in computer performance. Recent advancements have been made possible by the creation of interfaces between artificial intelligence and other fields of study, such as biomedicine, and by the collection of enormous amounts of data from a variety of fields, notably those related with the healthcare industry. First, Artificial intelligence helps with situational awareness, which is relevant in animal health and animal husbandry because it allows for the detection of patterns like repeated sequences of observations, forms like a protein, and signals like increased mortality especially in comparison to a baseline at various scales. A third option is computer-based decision making, or more practically, human decision support via knowledge - based systems, diagnostic support, and resource allocation, for instance.

Biostatistics is a branch of statistics that focuses on the analysis and interpretation of data from biological and health-related research studies. It involves the application of statistical methods to design, collect, analyze, and interpret data from studies involving living organisms like: animals, birds including human beings. Biostatistics plays a crucial role in public health, medicine, epidemiology, genetics, and other related fields.

With the increasing availability of data and advancements in biostatistics, breeders can expect further improvements in breeding practices that will results in better outcomes for both livestock farmers and the animals they breed. Animal breeding is a crucial aspect of agriculture and food production, as it helps to improve the quality and quantity of animal products as well ensuring food security to the masses.

Introduction

Estimated breeding values (EBVs), often estimated for sires, are used in traditional animal breeding (TAB) programmes to make selections based on an animal’s performance and that of its relatives. Using, typically, the best linear unbiased projections, EBVs are calculated using attributes measured in own performance, pedigree, sib, and/or progeny evaluation schemes in specialised testing stations and/or selected farm conditions (BLUP; Henderson, 1975). One of the main time-consuming challenges for phenotypic evaluation to enable a meaningful estimation of breeding values is generation intervals of 4 to 5 years in beef cattle, more than 5 years in dairy cattle, and 2 to 2.5 years in pig breeding schemes (Schefers and Weigel, 2012). Modern breeding techniques like marker-assisted selection (MAS) and, more recently, genomic selection (GS) are based on the use of genetic DNA markers to aid in selection and breeding (Williams, 2005). The fundamental reason why MAS, that only further uses a few markers as a selection tool, hasn’t made as much progress as was initially anticipated is that finding trustworthy markers is challenging, particularly when dealing with complex traits. Only relatively few consistent markers could be identified, despite successful identification of many quantitative trait loci (QTL; Hu and Reecy, 2007)

Livestock breeding for genetic improvement faces many challenges including feed conversion efficiency, fertility and adaptation to changing climate. These improvements have to be realized while maintaining or improving the nutritional properties of meat, milk and other animal products while giving emphasis to animal health and wellbeing also. Environmental stresses induced by climate change affect livestock productivity, reproductive efficiency and health, resulting in severe economic losses. Under the current climate change scenario, the viability of producing animals for human consumption is in jeopardy. In order to lessen the negative effects of heat stress in today’s world, it is urgently necessary to develop methods that are centered on breeding animals with increased thermal tolerance and climate resilience. The breeding of animals having genetic potential to sustain under changing environment conditions can be achieved through the various molecular genetics tools.

Livestock is one of the fastest growing agricultural subsectors in developing countries. In India has a vast diversity of animal genetic resources. Among them, sheep is an important ‘five star’ livestock species contributing significantly to rural economy through production of mutton, wool, manure, skin and milk etc. Sheep make a valuable contribution to the livelihood of the economically weaker sections of the society. The total Livestock population is 535.78 million and total sheep population is 74.26 million in in the country showing an increase of 4.6% and 14.1%, respectively over Livestock Census-2012. And it’s ranking 3rd in the world after China and Australia. Rajasthan is the fourth largest sheep rearing state in India with 7.9 million population (Livestock Census, 2019). Malpura sheep is one amongst the heaviest sheep breed of India, widely distributed in the semi-arid region of Rajasthan, mostly Tonk, Jaipur and Sawai Madhopur districts. Malpura sheep is reared and improved for mutton production since year 1975 at CSWRI, Avikanagar. The objective since then has been to improve the growth characteristics of this sheep breed for producing more carcass yield.The sheep is known for its adaptability to the harsh environment and potential for high meat production.Coat colour of Malpura sheep is white with coarse wool. The face is light brown with short, blunt ears. Animals have square compact body and long legs. Farmers also have liking for the long tail of animals for aesthetic purpose. The farmers like Malpura sheep for its properties like good mothering ability and produce sufficient milk to sustain and accelerate the growth of their neonates (Mishra et al., 2005), higher weight gain, number of lambs weaned, wool quality, walking capacity and the ease of management.

Introduction

Wool which obtained primarily from sheep is an essential textile fiber that is used across the world. Whether for clothing, canvas work, carpets, or even upholstery, wool is a vital resource supporting many industries and occupations. This natural fiber has many benefits, such as being biodegradable, easy to clean and even having a natural structure that traps air which is excellent for heat retention. The annual wool production is 2 million tones. China ranks first in terms of global wool production. With a production of more than 333,624 tonnes of wool in 2020, China accounts for approximately 19% of the global wool clip. Australia produces 16% of global wool and is by far the largest wool exporter in the world. There has been a constant increase in the demand of wool products worldwide. This has made scientists to try to improve livestock and livestock associated derivatives. The conventional system along with the recent biotechnological interventions will be helpful for enhancing wool quality and production.

The global human population is increasing exponentially with time, and it is expected to reach 9.6 billion by 2050 (UN 2013). With rapid population growth, food consumption is predicted to more than double in the next 40 years. Due to limited land resources for cultivation and a stabilising trend in agricultural productivity, the role of livestock sector is increasing significantly to meet the rising food demand. Meanwhile, global livestock production has increased significantly in both number and productivity. Unprecedented urbanisation has a significant impact on food consumption patterns in general, as well as demand for livestock products. Animal diseases are a significant factor in reducing livestock productivity, particularly in developed countries. The limitations of traditional animal breeding hinder further improvement of livestock productivity. The use of biotechnological tools has major applications in improving animal health and production, increasing disease resistance, using assisted reproductive techniques, improving rapid diagnostic techniques, and improving vaccines in livestock systems. These interventions cover advancements in feeding, nutrition, genetics, reproduction, animal health control, and overall improvement of animal husbandry. Since genomic tools and selection have been widely adopted in developed countries to improve both productivity and quality of animal products, the prospects for increasing productivity in developing countries using genomic tools and selection have not been adequately investigated.

Introduction

The key factor of sustainability in the animal sector depends upon genetic improvement in domestic livestock. There are many reproductive and molecular biotechnologies used for the genetic improvement of domestic livestock and they are synergistically coupled with the breeding program in distinct breeding targets. With the help of gene editing techniques (e.g. CRISPR etc.). To improve the specific traits of interest scientists can add, delete or replace the nucleotides (e.g. milk production, meat production, disease resistance, etc.) in less than one generation. Gene editing with the conventional breeding program in livestock is an important factor for genetic improvement for increasing the rate of genetic gain. In the present topic, here, we delved into the most important reproductive and molecular technologies used in livestock genetic improvement, as well as the most effective ways for incorporating gene editing into existing genetic improvement programmes and targeting specific traits for enhancement. The improvement in genetic level is a most powerful part of sustainable animal development because it is permanent and the effects are long-lasting and cumulative. Genetic advancements produced in one generation are passed on to the following, unlike dietary and animal health treatments, which are a continuous process. The many livestock operations that involve chemical and mechanical methods such as dehorning requires time, worker, money, animal safety, etc., but their genetic alternation of the concerned gene for the polled or hornless condition can exclude the requirement of physical dehorning. (Gottardo et al. 2011; Tompson et al. 2017).

India is bestowed with a wide variety of livestock species which forms the backbone of the economy of majority of the farmers. Cattle are one of the important species domesticated by man mainly for their draftability in agricultural operations. Rearing of cattle is an integral part of the Indian agriculture as it is always considered as a subsidiary enterprise of the agriculture farming. The indigenous cattle are well known for their adaptability to the harsh tropical climatic conditions, ability to thrive in the resource poor production systems, better feed efficiency and disease resistance. Barring few dairy breeds, majority of the Indigenous cattle breeds are poor in their genetic potential for milk production. Considering the ever increasing demand from milk , the country has implemented many cattle improvement programmes like Central Herd Registration Scheme (CHRS), Intensive Cattle Development Programme (ICDP), All India Coordinated Research Project (AICRP) on Cattle National Programme for Bovine Breeding and Dairy Development (NPBBD), National Livestock Mission, National Project for Cattle and Buffalo Breeding (NPCBB), Rashtriya Gokul Mission (RGM) etc., for improving the milk productivity of cattle.