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Small ruminants are the mainstay of arid, semiarid and rain fed agro ecosystem of the country and carry tremendous potential to contribute to rural livelihood and economy of developing nations like India owing to its short production cycle, quick returns as well as premium quality meat. Out of 148.88 million total goats in India, around 63.5 per cent are of non-descript nature, while 27.4 per cent are pure and 9.1 per cent are graded goats. There is a huge scope to improve the production potential of non-descript goats through introduction of elite males from purebreds native to the region or from adjoining region. The selection of breeding animals in relation to maximizing the reproductive efficiency depends upon males selected for breeding. Artificial Insemination permits intense selection of sires with exceptional merits and provides opportunity to exploit the value of superior sires. This book constitutes an update of recent developments in the field of assisted reproductive technology which includes selection and management of breeding buck, semen collection, processing and cryopreservation, estrous synchronization and Artificial insemination, pregnancy diagnosis and quality control in Artificial Insemination. Recently in some of these fields remarkable progress has been made. 

Globally there is growing demand for small ruminant production especially, goats for meat and milk purposes to feed the ever-increasing human population. As per 20th Livestock Census released by Department of Animal Husbandry & Dairying, the Goat population in the country in 2019 is 148.88 million showing an increase of 10.1% over the previous census Out of 148.88 million Indigenous Goats (Including Non-descript), 27.4% are pure breed, 9.1% are graded breeds and the remaining 63.5% are non-descript breeds. The goat population has increased at a faster growth rate in India and varied from 0.94 to 5.10% with an average of 3.05% during 1951-2013 in spite of about 41% slaughter and about 15% natural annual mortality. India produced 21.71% of the milk, 10.47% of the meat and 13.15% of the fresh skins of the world goat production worth of Rs. 1,06,335 million per annum. The goat husbandry also generates about 4.2% rural employment over 500,000 remote villages. It contributes nearly 8.5% of the total GDP from livestock sector to Indian agriculture production system. So, to increase the productivity per goat, we need to improve the breed quality scientifically.

The goats play a vital role in the economy of the poor and marginal farmers of rural India. Notwithstanding the fact that the goat population has shown a steady growth over the year’s very little effort has been taken for genetic improvement at farm level. As per 20th Livestock Census, 27.74% of the livestock population is Goats. Out of 148.88 million Indigenous Goats (Including Non-descript), 27.4% are pure breed, 9.1% are graded breeds and the remaining 63.5% are non-descript breeds. So, to increase the productivity per goat, we need to improve the breed quality scientifically. Artificial insemination (AI) using frozen semen is practiced to produce superior progeny and to accelerate the up gradation of stock. The conception rate with AI is lower but it has great potential to multiply superior quality of goat with faster rate. This technique also spread elite genetic material throughout a population with increased rate of genetic improvement. This technique is also important for the breed conservation process and has paved the way for other reproductive biotechnologies. The sufficient elite germplasm of male buck is not available throughout the country to cover breeding programmed by natural mating. AI is the best solution to improve the quality and productivity per goat.

The male genital system consists of: The pair gonads, the testes Epididymis Vas deference or ductus deference Accessory glands (Seminal vesicles, prostate glands, & bulbo-urethral glands)

In male animals, endocrine regulation of reproduction is mainly controlled by pituitary gonadotrophins and gonadal androgens. It is not same as in females as there is only negative feedback controls in case of male while it is positively as well as negatively feedback control in females. In other words the synchrony of pituitary gonadotrophins with gonads in male is non cyclic while in female it is cyclic i.e. after castration the pulse frequency of LH and FSH is retained Sex Hormones are sex specific e.g. estrogen and progesterone works primarily in females and testosterone in males but sex specificity is limited as far as sexual behaviour is concern. As estrogen injection in castrated buck recovers the maleness while testosterone injection in ovariectomized female maintain the receptivity for male up to certain extent. Hypothalamus acts as interface between nervous system and endocrine system. GnRH synthesized in neurons in hypothalamus, released at nerve endings episodic manner and transferred via hypophyseal portal system to anterior pituitary to stimulate the secretion of gonadotrophins.

India is the largest goat producing countries in the world exhibiting rich diversity between and within goat breeds. The implementation of a genetic improvement programme requires a clear breed-based breeding objectives and selection criteria, tailored to the needs of goat farming community. Indigenous goat breeds bear a great degree of adaptability for climatic stress, tropical diseases and low quality feed resources, require low inputs for enhancing productivity, thus, little investment along with use of high merit bucks bring a great change in the economy of the farmers. There are currently 37 recognized goat breeds in the country which are kept mostly in small herds on extensive or partial semi-intensive feeding system. Productivity of Indigenous goats, however, observed less than their actual genetic potential and attributed to low input system, lack of suitable breed specific structural genetic improvement programme and poor adoption of technologies. A buck is the most important animal in the herd. A breeding male or buck contributes 50% of the genetic merit of the herd and also determine the future improvement rate.

Ian Donald in the year 1956 used the one-dimensional A-mode (amplitude mode) to measure the parietal diameter of the fetal head and thus introduced the ultrasound in diagnostic and medicine. Ultrasonography does not use radiation or powerful magnetic field as source of energy and the equipment cost is usually affordable. This modality involves the use of sound waves in viewing the longitudinal, sagittal and transverse planes for both testes . Sound is measured in cycles per second or hertz (Hz); the audible range of sound is from 20-20,000 Hz. Diagnostic ultrasound is usually in the range of 1–20 megahertz (MHz). The speed of sound depends on the tissues through which it propagates because density and compressibility change the speed, the sound wave travels. On an average the assumed speed of sound in soft tissue is 1540 m/s.

The goat rearing on extensive rearing system has been practiced since ancestry for livelihood and nutritional security of poor, landless and marginal farmers of our country with the flock size ranging from 2-10 goats. However, in the recent past, goat rearing is shifting towards semi-intensive and intensive rearing systems for commercial purposes with flock size ranging from 25 to 500. The goats reared in small flocks needs minimal housing facilities following the scientific principles with low-cost structures. On the other hand, elaborate housing is generally recommended for goats raised under large scale commercial production systems. Separate housing arrangements for different categories of animals viz. growers, pregnant females, lactating females, breeding males, etc. are to be ensured for rearing goats scientifically for harnessing maximum output sustainably.

Nutrition is the key factor affecting the production as well as the reproduction efficiency in all the animals therefore proper and balanced nutrition is the prerequisite to attain and utilize the full reproductive potential of the animals. All the nutrients like energy, protein, minerals and vitamins need to be properly balanced in the diet of animals. Energy and protein are the major nutrients required in the greatest amounts and should be in the topmost priority in order to optimize reproduction. Although minerals and vitamins are required in low amount, but very much essential as a cofactor and coenzymes in the reproductive process of the animals and deficiency of these nutrients might affect the overall reproductive efficiency of the animals.

Occasionally some diseases can be noticed in male animals, which are responsible for the reduced reproductive performance of the bucks. Sometimes these diseases can damage or obstruct the male reproductive passage and responsible for the infertility and sterility in the bucks. This type of infertility may be associated with pathology of testes, epididymis, vas deferens, accessory sex glands, and urethra or may be associated with abnormal semen production due to congenital or hereditary causes or due to acquired causes.

India has rich diversity of goat genetic resources and as per 20th livestock census (2019), there are 148.88 million goats in India. They are mostly found in arid and semi-arid regions of the country and one of the mainstay of dryland agriculture system. Out of 148.88 million, around half of them (75 to 60 million goats) are found in Rajasthan (20.84 m), Uttar Pradesh (14.48 m), Madhya Pradesh (11.06 m), Maharashtra (10.6 m), Tamil Nadu (9.89 m) Karnataka (6.17 m) and Gujarat (4.66 m). Out of total goat population, only 35 % of the goats are of either pure breed or upgraded nature resembling the some of the local breeds. There is huge scope to improve the productivity through use of assisted reproductive tools like artificial insemination and estrus synchronization in field condition to upgrade the non-descript population in relatively shorter period of time as compared to natural services.

The animals are mostly social ones and prefer living in herds. In each species there are certain rules for group survival, cohesion, defence and also for propagation. The basic patterns of male sexual behaviour appear to be innate in nature. Kids of both sexes are very often seen exhibiting sexual display during play and mounting is seen most commonly. In females the sexual receptivity is restricted to few hours or days near the estrous phase of the estrous cycle, while in males the sexual receptivity is grossly permanent. The physiological signals for arousal of sexual motivations originate from gonadal steroid balance. However, the secretion of gonadal steroids is not permanent. In males the androgen secretion is in the form of several peaks within 24 hours reflecting the pulsatile release of pituitary gonadotropins. However, the total amount of androgen in males is almost constant practically for day to day. In females the secretions of estrogens are restricted only during few days (follicular phase) of the estrous cycle.

Hygienic collection of semen is an integral part of the artificial insemination process. Semen collection implies mounting a teaser doe or a dummy. Therefore, proper semen collection deserves the utmost attention. Sexual efficiency is measured by the percentage or successful semen collections among attempted collections. When males are allowed to female teaser, the male exhibits characteristic behavioural symptoms such as sniffing, nudging or mounting at that time it is necessary for the operator to attempt an approach. This approach has to be done quietly to avoid a fear reflex in the male. The male, even if it mounts the female, deviation of its penis into the receptacle. Under the circumstances, the operator should not more from his squatting position, so that the male does not associate the two events. The animal generally comes back by itself to attempt remounting the female and will serve the artificial vagina. The operator should also stimulate the male by voice.

The following objectives are accomplished by semen dilution/ extension Preservation of semen potential over a long period of time. Increase in the number of services per ejaculate. Ideally approximately 40 does can be inseminated from diluted/ extended semen of a single ejaculate. Extenders provide the spermatozoa with a medium in which they are able to remain viable and fertile for a prolonged time period. An ideal extender should be able to provide a conducive environment to facilitate sperm survival and modify the sperm structure to prepare them for freezing through the following properties: It should be isotonic with blood and should maintain this during preservation. It should have capacity of maintenance of pH (6.6-6.8) with high buffering capacity in that range.

The semen evaluation is of great importance in predicting fertility of the male. There are several parameters to evaluate the semen quality. Usually bucks with good semen samples have good fertility and bucks with poor or very poor semen samples are invariably infertile or sterile. A single test is never sufficient to assess the semen quality and the examiner should be acquainted with several tests to evaluate the semen. The semen should be examined with in a shortest possible period after ejaculation and the ejaculate must be properly protected and handled until examination. Semen can be evaluated by following methods Macroscopic test Microscopic test Metabolic test

Modern Semen Evaluation Methods Fluorescent Microscopic Evaluation In-vitro Fertility Test Enzyme Estimation 1. Fluorescent Microscopic Evaluation 1.1. Acrosomal Integrity (Giemsa method and FITC-PSA assay) The acrosomal integrity of the spermatozoa was detected using Fluorescence isothiocyanate – Pisum sativum agglutinin (FITC-PSA) staining procedure adopting method of Mendoza et al. (1992). Pisum sativum agglutinin (PSA) when conjugated to Lectin FITC marks the intact acrosome with bright green fluorescence. PSA is an agglutinin from edible pea that binds to glycoconjugates of acrosomal matrix or outer acrosomal membrane. It has affinity for terminal α –D-glucosyl and α-D-mannosyl residues of glycoproteins and it binds specifically to sugar α-mannoside found in acrosomal content.

Biological and chemical reactions in living cells are dramatically reduced at low temperature, a phenomenon that can lead to the possible long-term preservation of cells and tissues. However, freezing is fatal to most living organisms, since both intra and extracellular ice crystals are formed and results in changes to the chemical setting of cells that lead to cellular mechanical constraints and injury. The major hurdle for cells to overcome at low temperatures is the water-to-ice phase transition. Cell injury at fast cooling rates is attributed to intracellular ice formation, whereas slow cooling causes osmotic changes due to the effects of exposure to highly concentrated intra and extracellular solutions or to mechanical interactions between cells and the extracellular ice. Cryopreservation is a process that maintains biological samples in a state of suspended animation at cryogenic temperature for any considerable period and is used to preserve the fine structure of cells (Jang et al., 2017).

All living organisms need to reproduce in order to maintain their species and improve the economics of animal husbandry. Since the beginning of time, different methods of successful reproduction have been created, including artificial insemination and in vitro fertilization. To shield sperm from damaging elements like freezing, osmotic shock, oxidative stress, and cell damage by ice crystals, semen extenders were developed. Semen extenders maintain sperm’s characteristics, such as its morphology, motility, and viability as well as its membrane, acrosomal, and DNA integrity. To improve semen quality for fertilization, semen extenders must offer a suitable pH, adenosine triphosphate, anti-cooling and anti-freeze shock, and antioxidant activity. As a result, this compilation of research offers exact information on various semen extenders, preservation mechanisms, and crucial semen extender additions in goats. By incorporating various types of additives in semen extenders for cryopreservation, significant improvement is reported in post thaw sperm quality in terms of increased % motility, viability, PMAI, MMP and reduced DNA fragmentation, capacitation like changes reflected by less CTC pattern B and AR, Tyrosine Phosphorylated pattern A, E and AE.

Goats remain an important and instant source of income as well as livelihood for the majority (70-90 %) of small and marginal farmers in India. Goats are the animals with multiple utility like milk, meat, hide, fibre and manure. They are more tolerant to harsh environment (better resistance to heat stress and drought, better utilization and digestibility of pastures) and give more production per unit investment. Goats are spontaneously ovulating, poly-estrous animals and show seasonal pattern in reproductive activity related to the annual variations of photoperiod. Onset and length of their breeding period throughout the year is dependent on different environmental and physiological factors viz. latitude and climate, feed and fodder availability, breed and breeding system. This in turn affects round the year availability of meat and milk to full fill the market demands. When kids are born out of season, adequate supply of pastures along with good management practices must be ensured in order to minimize kid’s mortality and promote their optimum growth.

The selection of breeding bucks in relation to maximizing the reproductive efficiency depends upon males. AI permits intense selection of sires with exceptional merits and provides opportunity to exploit the value of superior sires. Young males can be trained for exhibiting sexual behaviors and semen collection through the uses of male, anoestrus doe or oestrus doe as dummy. Successful AI depends on precise management of semen collection, its frequency and use. The semen collection implies mounting a teaser doe or a dummy. Artificial vagina (AV) and electro-ejaculator (EE) are the two methods for semen collection in bucks. AV method is being used as universal method for routine semen collection whereas electro-ejaculation is generally used for collecting semen from untrained and valuable sires incapable of service. Moreover, this method of collection is painful for the animals. Semen evaluation should be rapid and effective so that collected semen samples can be processed for initial quality which ultimately affects the fertility. There are several tests for the assessment of semen quality but no single test is reliable to give definite prediction of the fertility.

Artificial Insemination (AI) is one of the most popular first generation assisted reproductive technology as well as a breeding tool, ever evolved for the genetic improvement of cattle and buffalo industry throughout the world. The advent of frozen semen has further revolutionized this technique. Presently, use of sex- sorted-semen in cattle breeding is also coming into vogue. Contrary to cattle and buffalo, use of AI in small ruminants has not gained such impetus. It has been reported that lower pregnancy rates were obtained when ewes and does are bred with frozen or extended liquid semen using intra-vaginal or intracervical technique of insemination. The reason being anatomy of the cervix of sheep and goats; cervix is long and tortuous with presence of 4-7 cervical rings. Furthermore, these cervical rings are directed caudally hindering the lumen of the cervix thereby causing hindrance (more prominent in sheep) while passing the AI gun during intra-cervical or trans-cervical AI (TCAI). There are several reports which support the fact that, as the depth of semen deposition into the cervix increases, the pregnancy rates also improve due to availability of a greater number of motile sperms for fertilization.

An early and accurate diagnosis of pregnancy is a crucial factor for successful management and maintaining cost-effective production in scientific goat production for better economic returns. In addition, accurate information on the stage of gestation would also be useful to dry off lactating females at an adequate period. The techniques for pregnancy diagnosis in goats are mostly depend upon visualization of the conceptus or determination of its secretory products in the maternal blood or the milk are the most defined and specific methods for pregnancy. The choice of pregnancy diagnosis method in goats depends on the stage of gestation. Some methods have a higher degree of accuracy at the early gestation while others do at the late stage of gestation. Assessment of pregnancy in terms of hormonal assay of blood plasma, serum, or milk, and estimation of pregnancy-specific antigens or proteins give a higher level of accuracy within 30 days of pregnancy. There are many methods that are currently being used for pregnancy diagnosis in goats. Among those, the method applied should be safe for both offspring and mother and need to be low-cost and easy to apply. Various techniques have different kinds of limitations to their wide-scale use. These techniques are classified into 3 classes, which are as follows:

Artificial Insemination is a very important tool that caters to propagation of high-quality germplasm and breed improvement. It is also economical as it aids in breeding without the necessary to maintain the adult bucks cutting the input cost. However, the bucks maintained for production of semen and AI should be free of any diseases and in specifically venereal diseases. Venereal diseases are not so uncommon in livestock, and they cause a variety of symptoms including orchitis, abortions, still birth, vulvovaginitis etc., leading to infertility in breeding animals. Venereal diseases are infectious in nature and they are transmitted mainly through semen, feed-water, AI gun, artificial vagina, fomites etc. Due to venereal diseases, infertility, orchitis, epididymitis, vasculitis etc. occurs in bucks and leads to abortions and still birth in does (Ahmed et al, 2010; Beena et al, 2017), because they are directly linked with the economic output (Sharma et al, 2008; Azawi et al, 2010) and overall health of the animal affecting the productivity significantly (Menzies, 2011). To keep abortions and other venereal diseases at bay, it is important to raise disease free breeding bucks that deliver clean-semen for natural service or AI operation. Abortion rate between 2 to 5% indicates its endemic nature and abortion level exceeding 5% requires aggressive investigation (Menzies, 2011). Infectious agents that include viruses, bacteria, fungi, parasites etc.; as well as noninfectious cause can lead to infertility in goats (Moeller, 2001; Szeredi et al, 2006; Smith and Sherman, 2009). Many infectious causes are known to mankind that leads to trans-venereal diseases in goats including Brucella melitensis, Chlamydiosis, Campylobacter spp., Listeria monocytogenes, Toxoplasmosis, Coxiella burnetii etc. There are numerous viruses such as

The major requirement that distinguishes frozen semen/IVF laboratory from other laboratories is the need to maintain aseptic conditions. The wash up and sterilization of media and other equipments should be located at one end of the room and clean area for sterilize handling at the other end, and preparation, storage and incubation in between. The storage and incubation area should be near to the sterile working area. In recent years, the introduction of laminar flow cabinets has been a great boon in providing a sterile working area and allows the use of unspecialized laboratory accommodation for culture work. For sterile work, area should be in a quiet part of the laboratory preferably in a cubicle where a laminar flow cabinet is suitably fitted. The area should be free from dust or draughts. Nothing should be stored on the laminar flow cabinet or bench used for sterile handling except most necessary equipments like holding pipettes etc. The laminar flow cabinets provide sterile air blown over the work surface. For laboratory, a horizontal laminar flow is more preferable as opposed to a vertical one because of ease of handling the ovaries etc. If an air curtain is provided at the door of the cabinet, introduction of dust etc. can be avoided. In India laminar flow are manufactured by companies like Clenzoids, Yorco etc, among others. The laminar flow size should be a minimum of 300 X 300 or 450 X 450 mm with a 12-18 in, square filter size).

The successful AI program depends on the health of the semen donors followed by hygiene in semen collection, processing, storage and AI methods as well as reproductive health of the females. However, the microbial contamination may not be able to avoid completely but it can be reduced to the minimum threshold level by adopting hygienic procedures. The hygienic condition of the neat / frozen semen samples can be assessed periodically by enumerating the bacterial load apart from the periodical screening of bucks for the presence of various causative agents in animals and its transfer to the females via semen samples. Though both viable and total (viable and nonviable) bacterial counts can be done, the viable techniques are more commonly used in diagnostic and food hygiene procedures. The viable bacteria are capable of multiplication with the production of visible colonies on or in agar media. In viable techniques, the assumption is made that one well-spaced bacterial cell gives rise to one colony. The bacterial colonies, rather than bacterial cells, are counted in these techniques. Among the viable counting techniques like Spread plate, Pour plate, Miles, Misra, Filtration are available and each has its own inherent errors, the pour plate counting method is explained as follows: