Veterinary College, Bengaluru Monthly e-Bulletin
Newsletter Date : 31 December 2015
Volume No: 4 Issue : 12
Dr A S Patil, Dr Ramesh Rathod and Dr B N Nagaraj Veterinary Hospital, College Of Agriculture, UAS Dharwad-005 (Email id:- patilas@uasd.in) Spinal anesthesia is the injection of local anesthetic around the spinal cord. When local anesthetics such as lidocaine or bupivacaine are used, all the segmental nerves (sensory and motor) which pass through the anesthetic are paralyzed, although when opioids are used only sensory block occurs. Spinal anesthesia is divided into two types; ‘epidural’ and ‘true spinal’. • Epidural (or extradural) anesthesia refers to depositing of local anesthetics into the extradural space. The needle enters the spinal canal, but does not penetrate the meninges. The anesthetic is therefore limited to the canal outside the duramater. • True spinal anesthesia refers to the subarachnoid access (usually known as ‘intrathecal’ anesthesia) in which the needle penetrates the duramater, and the analgesic is injected into the cerebrospinal fluid (CSF). Anatomical details The spinal cord is supported, protected, and stabilized by vertebral column, ligaments and meninges. (Figure 1) • The epidural space is located immediately below the ligamentum flavum separating the dura mater from the vertebral periosteum, the lining of the spinal canal. • The duramater, arachnoid membrane and piamater constitute the three meningeal membrane layers that protect the spinal cord. The duramater, meaning “tough mother”, is the outermost meningeal layer. The arachnoid membrane, thin and avascular, lines the inner surface of the duramater. The innermost membrane layer, the piamater, closely approximates the spinal cord. This layer is a highly vascularized membrane through which all blood vessels pass to enter and leave the CNS. • Cerebral spinal fluid (CSF) is located in the subarachnoid space, which separates the arachnoid membrane and the piamater. •
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Effects of subarachnoid and epidural anesthesia • The requirements from these techniques is paralysis of sensory nerves to the area in which surgery is going to be performed. • Muscle relaxation can be an added bonus or a disadvantage. • Muscle relaxation of the limbs causes recumbency; and of the thoracic region limits respiratory movement. If local analgesic reaches the cervical region and affects the phrenic nerves, then respiration ceases. • Thus most spinal and epidural anesthesia is injected in the caudal regions of the animal, although there are several variations in terminology used, generally where injection of drug is in the coccygeal region and the dose of drug is such that the hind limbs are not affected, it is termed “caudal anesthesia” where a higher dose of drug is given, still at the coccygeal area, so the hind limbs may be just affected, the term “epidural anesthesia” is used, and where the block extends to the abdominal region, either because of the volume used, or because the injection is carried out at the lumbosacral space, the Figure 2. Diagrams to show various term used is “anterior epidural”. (Figure 2) epidural blocking sites . The area blocked by epidural anesthesia will depend on The site of injection: Common sites used in veterinary medicine (depending on the species) are the sacrococcygeal or intercoxygeal space, and the lumbosacral space. However, it is possible to carry out “segmental” blocks using other points of injection (widely used in man; development in veterinary use only just under way). • Quantity, volume of and specific local anesthetic injected: • Size of the spinal canal:This varies not only between species of the same weight, but between breeds; with age; and with condition of the animal (e.g., fat/thin etc.). • Position of animal :(effects of gravity on spread). • Removal of the anesthetic from the canal: Again this depends on multiple factors, including age (influences size of “holes” in the dura around the nerves), condition, blood flow etc. The use of vasoconstrictors (epinephrine) will delay removal. ‘ Dangers of spinal and epidural block • Infection- Careful sterile precautions (good clipping and scrubbing) • Irritation causing spinal damage (most likely with subarachnoid). • Hindlimb motor paralysis (problem in large animals, acceptable in small). • Hypotension - most likely with an anterior block. Where this is being done fluid therapy or inotropes should be available to maintain blood pressure. • Respiratory paralysis (only if massive overdose of local analgesic used). Epidural anesthesia in the Dog and Cat. • The epidural injection site in dogs and cats is located at the lumbosacral junction between the seventh lumbar (L-7) and the first sacral vertebra (S-1). •
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In cats, (and small ruminants, cattle), however, the spinal cord terminates at the 3rd sacral vertebra (in ruminants, it is in S-1), and both the spinal cord and subarachnoid space are very close to the site of epidural injection. To locate the site, identify the iliac prominences on either side, and take an imaginary line between them crossing the dorsal spinous process of the last lumbar segment. The site for the needle insertion is immediately caudal to this, in the midline. Restrain laterally or in sternal recumbency (personal preference). The hair over the lumbosacral junction should be clipped and aseptically prepared. A 20-22 gauge, 1.5-2.5 inch spinal needle may be used; depending on the size of the animal, a longer 3.5 inch spinal needle is used for obese and large animals. To reach the epidural space, the needle must be passed in a ventral direction through the skin, subcutaneous fat, supraspinous ligament, interspinous ligament and ligamentum flavum (yellow ligament). If the needle continues ventrally past the epidural space it will encounter the dura mater, arachnoid membrane, pia mater and finally, the spinal cord. To perform epidural anesthesia, the injection must be made only into the epidural space, between the ligamentum flavum and dura mater. Epidural injection should be differentiated from spinal (or intrathecal) injection, in which the anesthetic is injected into the subarachnoid space, between the arachnoid membrane and the pia mater (this is also where the myelogram is performed in the disc problem dogs). Anesthetic agents injected into the subarachnoid space (spinal injection) produce true spinal anesthesia because of the lack of protection provided by the dura mater and arachnoid meninges. Consequently, the volume of the anesthetic solution must be reduced by one third. Hypotension can be a major complication. This procedure should not be carried out unless there is an intravenous line in place so fluids or anti-hypotensives can be given promptly. The epidural space is identified by advancing the needle from an area of high resistance (ligamentum flavum) to an area of low resistance (epidural space). This is usually accomplished using the “hanging drop” or the “lack of resistance” technique during injection. For cranial laparotomies or hindlimb orthopedic procedures a dose of 0.1 mg/kg of morphine with/without 0.5% bupivacaine of approximately 1 ml per 10 Kg is required.
Epidural anesthetic techniques: The “hanging drop” technique : This involves removing the stylet of the spinal needle, filling the hub of the needle with saline or anesthetic solution, and allowing one drop to hang from the hub (Figure 3). • As the needle is advanced through the ligamentous structures, the drop does not move. • However, upon penetration of the ligamentum flavum, the negative pressure in the epidural space will draw the drop of solution into the needle, indicating proper placement in the epidural space. •
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A “pop” felt through the
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A “pop” felt through the needle is usually encountered when the spinal needle is passed through the ligamentum flavum. • The chance for a successful “hanging drop” technique is greater in large dogs than in smaller dogs and cats. • If the “hanging drop” technique fails, the “lack of resistance” technique can be used. •
The “lack of resistance” technique This indicates proper placement of the injection needle in Figure 3. Diagram showing various anatomic the epidural space based on the amount of resistance to landmarks and positions of needles to perform epidural block technique. the injection of air or saline. • Once in the epidural space, the injection of air, saline, or anesthetic solution will encounter minimal resistance. • A separate syringe of normal saline (3 ml or air preferred by others) should be prepared for the “lack of resistance” technique. • When minimal resistance to the saline injection is encountered, the saline syringe is replaced with a syringe-containing anesthetic, and the injection is completed. •
• To rule out the possibility of administering drugs into the venous sinus (presence of the blood) or subarachnoid
space (presence of CSF), it is important to aspirate or allow a few seconds to check bleeding before epidural injection.
Epidural anesthesia in bovine • In the ox, the spinal cord ends in the region of the last lumbar vertebra, but the meningeal sac goes to the 3rd/4th sacral segments. • For caudal and epidural anesthesia the injection site used is between coccygeal C1 and C2 (located by raising tail in “pump handle” fashion, the first obvious articulation behind the sacrum being C1 /C2). (Figure 4)
Figure 4. Location of Sacral-Coccygeal/Inter-coccygeal junction for the epidural injection in cattle. Epidural anesthesia in the horse • The technique is less reliable than in cattle. Site of injection is usually sacro-coccygeal junction but can be between C1 and C2. Epidural anesthesia in the sheep and goat •
In both sheep and goats, anterior epidural anesthesia, induced by injection at the lumbosacral junction is easily performed and provides excellent analgesia and muscle relaxation for abdominal surgery.
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Dr. Madhukar Assistant Professor, Institute of Wildlife Veterinary Research, Doddaluvara, Coorg, Karnataka – 571232; (Email Id:madhukar262@gmail.com) Elephants are not ‘just any other wild animal’. These mega animals are nature’s architects, engineers and gardeners. Elephants play a vital and profound role in supporting the ecosystem as well as survival of other wild animals; which makes elephants a keystone species of paramount significance. A keystone species is a species that has a large affect on its environment relative to its abundance. Such species balance and maintain the structure of ecological communities. Hence, a loss of elephants from its habitat means leads to disastrous effects on the complete ecosystem. Let’s look at a few roles elephants play. 1. Elephants disperse seeds: Elephants travel a lot. This means that the food consumed at one place comes out as dung at a distant place. Elephants spread seeds when they eat and move. Elephants disperse seeds by eating them, transporting them, and then spreading them through their dung. Elephants are highly frugivorous (fruit eaters), which combined with their large food intake makes them a high quality seed disperser. Studies have showed that elephants routinely disperse seeds up to 60 kms. Some plants, like ‘Balanites Wilson’ depend completely on elephants for seed dispersal as no other animals perform this. Seed dispersal by elephants is largely responsible for the natural cycles of rejuvenation of ecosystems. 2. Elephant dung is not just an end product of digestion The dung provides a suitable atmosphere for the growth and germination of seeds. Unlike other dung, fungi grow very easily in elephant dung as it provides the suitable environment. The digestibility of elephants is very poor, and only half of all the food eaten is utilized. This makes the dung a very rich in fibers and minerals. These minerals act as fertilizers for the soil and in turn support the growth of numerous species. Elephant dung is food for numerous species of birds and animals! For instance dung beetles, many insects, ground hornbills, velvet monkeys, banded mongoose, and baboons and devour elephant dung. The beetles make rolls and store as food supply for larvae. However, it is another story that honey badgers dug up the stores and steal the dung balls to feed on the larvae! Elephant dung piles it itself form highly diverse ecosystem of invertebrates! Ants, beetles, millipedes, centipedes, crickets, scorpions, spiders and termites start living in elephant dung. The dung pile acts as both feed and shelter. Vertebrates like frogs (3 species in Sri Lanka) also convert dung into their shelter.
A fusiform incision is created
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Elephants help many other species get nutritious and diverse foods! Elephants like variety and feed on hundreds of plants and grass. While plucking and feeding fruits and leaves from tall trees, plenty of it falls on ground that is consumed by other sources, which otherwise these may never get. 3.Elephants spot water Elephants need large amount of water regularly. They have a keen sense of smell and can smell water from more than 25 kms. Coupled with this, their acute memory of direction and routes, guides elephants to the water sources and can be life saving during summers. Some tribes in Kenya follow elephants to find the source of water. Elephants even dig out water holes to create wells, opening a source of water for all other species. 4.Elephants modify habitats Elephants stomp round, strip the tree barks, push and pull the trees, and so on. This actually alters the habitat for the good. Elephant herds have transformed many a woodlands into grasslands, creating a source of food for many herbivores. More herbivores mean more carnivores. Good for all the species! If elephants are removed from their habitats, the grasslands are ultimately converted to woodlands that harbor only thorny trees and shrubs, making it inhabitable for herbivores. Elephants open up dense woodlands by creating gaps in the forests due to their movements. These gaps, that were un-inhabitable earlier becomes home for other species. This enhances the biodiversity of an ecosystem. The light that reaches deeper and wider due to these gaps has been found to support the survival and proliferation of numerous species like buffalo, deer, and gorillas and so on. Elephants are classified endangered. This literally means all the ecosystems inhabited by elephants are also endangered. These are just a few reasons ecological researchers are worried about elephant decline. Who will do these profound ecological services if elephants are gone? The answer is simple – nobody can!
Dr. Ranjith. D Assistant Professor, Department of Veterinary Pharmacology and Toxicology, CVAS, Pookode. Email Id: ranjith946@gmail.com Theory of homeopathy - ‘Minma minimus’ – smaller the dose, better the result. Veterinary medicine supervened in the footmark of Human medicine. High cost, inherited side effects, problems of antimicrobial residues in animal products caused apparent discomfort to animal owners invoking their interest in alternative approaches of animal health care. Among alternative approaches, Homeopathy (developed by Dr. Samuel Hahnemann (1755-1843), a German physician) is widely accepted as a complementary and alternative near and is in buzz for around 200years.
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Homeopathy is a system of complementary medicine in which ailments are treated by minute doses of natural substances that in larger amount produces symptoms of ailments. It is based on principle that ‘Similia Similibus Curentur’ meaning “like cures like”, any substances which produce symptoms in a healthy person can cure similar symptoms in a person who is sick in smaller doses. For instance, onion is the substance which makes the eye watery and nose to burn, if succumb with hay fever evidenced by watery eye and burning nose, homeopathic remedy made of onion is of significance. Secondly, homeopathic preparations should be given in least amount of medicine necessary to evoke a healing response. Currently there are three thousand homeopathic preparations for treatment ranging from cold and cough to arthritis and cancer. Veterinary Homeopathy: In humans for effective homeopathic therapy a number of things should be prohibited (alcohol, tobacco, smoking, coffee, and use of perfume, camphor). Fortunately, with animals there is no such problems which strengthens the therapy for domestic animals and birds. Homeopathic treatment of animals was introduced by Baron Von Boenninghausen (1785-1864), who established the principles of Veterinary Homeopathy. The use of homeopathy in veterinary medicine has been growing worldwide. It can encounter remedies on immense number of species including; cattle, buffalo, sheep, goat, dog, cat, horse, llama, alpacas, bats, bees, caribou, rats, mice, pigs and snake. It can treat multifarious conditions from emotional issues (aggression, anxiety, fear) to infectious diseases (parvovirus, kennel cough, pneumonia etc.). This reinsuring demand for remedies, delivers excellent support for the promotion and acceptance of homeopathy. Although, encounters critics that homeotherapeutics are much diluted and merely have a placebo effect. However, recent research conducted by the department of chemical engineering, IIT-B proved that homeopathic preparations do contains molecules which exists in nano sizes called nano-particles of medicinal values and physicists at BARC use laser beam and electrical devices to detect the effect of energy particles in homeopathic preparations which have a beneficial effect on host. Global research in homeopathy have demonstrated the regression of cancerous cell lines from rats administered with homeopathic medicine. Homeopathy is advanced; it is green and friendly to the environment, ecology and economy. Sources of homeopathic drugs includes from minerals, vegetables, animals, nosodes, sarcodes and imponderabilia, during compounding these substances were converted in to sub-molecular preparations by a process called “Potentization”, which increases the healing effect and reduces toxicity of crude formulations. Incipiently, homeopathic drugs viz. Aconitum napellus, Camphora, Nux vomica and Opium were used for the treatment of diseases in horses and cattle as early as 1833. In India, many Veterinarians are using homeopathic drugs for treatment of animal diseases, though lack of planning and execution, which makes the claim of miracle cure unacceptable. The objective is to add one more effective weapon for the use by veterinarians against the diseases. VETERINARIAN STANCE TOWARDS HOMEOTHERAPY: Veterinary Homeopathy is distinguished as a separate discipline in United States and Europe’s academic programme.
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In India, a survey conducted on veterinarians about the use of homeo drugs in animals, they opined that homeopathy along with allopathic system would make clinical practice more fruitful. Because, this system is cost effective, eco-friendly and increases the spectrum of treatment. ADMINISTRATION OF HOMEOPATHIC MEDICINE TO ANIMALS: Homeopathic medicines are very delicate, avoid touching with hands. Store in a cool dark place, away from sunlight and strong smelling substances. Do not refrigerate and freeze. Homeopathic medicines can be administered both internally and externally. Preferably, these medicines are given internally about 30 minutes prior to feeding schedule. INTERNAL USE: Mother tincture: It is a concentrated form of plant juice or elemental extract (mercury, sulphur) prepared by filtration and extraction in hydro-alcoholic mixture. 10 drops of tincture mixed with cold water and drenched by bottles for large animals and five drops of tincture for small animals (sheep, goat, swine and dogs). Triturated powder or pills: Trituration is a process by which a solid substance is mixed and grounded with pure lactose powder to produce a colloidal gel. Further, mixed with alcohol and water to form mother tincture. Triturates or pellets may be placed on tongue or mixed with feed and given to animals. The powders are given @ 2 grains for large animals and @ 1 grains for small animals. Potentiated dilutions: One drop of mother tincture is diluted with ninetynine drops of alcohol to give a potency of 1C. When one drop of potency 1C is diluted again with ninetynine parts of alcohol it gives 2C potency, with such serial dilution, potency 12C, 30C or 200C etc. can be prepared. Generally, remedies used in veterinary practice are of 30C potency. Potentised dilutions are administered by vehicles like globules, pellets or disks. The globules can be drenched or fed to sick animals along with food, medicated globules can be placed on tongue, gets dissolved in saliva and absorbed. If large number of animal has to be treated, the remedies may also be added to drinking water, also triturated powder or triturates can be mixed with feed. EXTERNAL USE: Few homeopathic medicines are used in the form of lotions and ointments. Lotions are prepared by mixing one tablespoonful of mother tincture with half a pint of pure water for external use. Guidelines for homeopathic drug administration: In homeopathy, mode of administration of drugs is based on “Organon of Medicine� guidelines which includes
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1. 2. 3. 4. 5. 6.
They should be kept in a place where there is no sunlight or strong odors and neither too cold or hot. Medicines are given by oral or olfaction methods. In no case, it is recommended to administer more than one medicine at any given time. It is wrong to endeavor complex means when simple intend suffice. This minute yet powerful dose of the selected medicine be repeated at intervals best adopted to cure. Magnitude of the disease, corporeal constitution, nature of substances will decide the dose and repetition of homeopathic medicine. 7. The diet and regimen which have any medicinal action should not be taken. 8. Medicines should not be given during their aggravation time of the drug. Is Homeopathy Safe? Homeopathic preparations are energetic medicines, free of any side-effects. They are nontoxic, they will not interfere with other medications and are non-addictive. The remedies are odorless and tasteless which makes them easy to give and to receive. They are safe for animals of all ages including newborns, pregnant and aged animals. Homeopathic remedies can even be used to strengthen plants, improve the soil (agro-homeopathy) and to dissuade insect’s garden. Does Homeopathy Work? Yes, absolutely. Homeopathy is effective for both acute and chronic maladies. The remedy resolves on deep-seated complaints such as arthritis, GIT disorders, urinary tract infections, epilepsy and respiratory illnesses. It is equally effective in acute and first aid emergencies like accidents and injuries, shock, bone fracture, pain, fever, vomition and diarrhea. Mental and behavioral problems such as fear of loud noises, spookiness, depression, aggression, panic and grief also respond very well to homeopathy. Its healing sphere is wide and is strong, yet the most gentle and humane of medicines, which makes it a remarkable system of healing. How does homeopathy works? The aspect of homeopathy that is implausible for many people is that the medicines are often diluted to the point where there may be no molecules of original substances left. One of the leading current proposals for how such ‘ultramolecular’ dilutions work is that water is capable of storing information relating to substances with which it has previously been in contact. Recent research on hydrogen bonds in water provides some support for this ‘memory’ theory. The researchers found that the structure of hydrogen bonds in homeopathic dilutions is of very different from that in pure water They reached the conclusion that the phenomenon results from the vigorous shaking of solutions that takes place during homeopathic ‘succussion’ and also suggested that as a solution is made more and more dilute, very stable and larger ‘clumps’ of material develop in dilute solutions rather than in more concentrated solutions. This means that residual molecular clusters of the original substance might just be present in homeopathic dilutions. Succussion might also be responsible for creating very tiny bubbles (nano-bubbles) that could contain gases including oxygen, nitrogen, carbon dioxide and possibly the homeopathic source material.
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However, there is increasing evidence that homeopathic dilutions have a demonstrable effect on living organisms examined under laboratory conditions. Recent research in Germany have observed an inhibitory effect of an ultra-diluted homeopathic preparations on the bacterium Vibrio fischeri. Viewing overall evidences, there is a strong experimental support for the idea that ultra-molecular homeopathic dilutions may possess characteristic physical properties and exert physiological effects (positive outcomes in 75% of experimental studies). Integrated approach: Homeopathy cannot replace all other forms of medicines, but can be used as the first treatment option in a wide range of conditions. It can also be used in a complementary way in other situations, for example, to support good recovery after operations. Homeopathy doesn’t interfere with conventional medicine and should be seen as a complementary treatment, not as an alternative. Despite the differences in approach, homeopathic and conventional treatments can work very well alongside each other. Advantages over allopathic drugs: 1) Free from smell and taste, readily acceptable, smallness of dose. 2) Environment friendly, safe and no withdrawal period, absence of drug residues and are easy to administer. 3) Economical, simple and effective in large animals, small animals, and pets. 4) Well suited for programme of preventive medicine and for organic farming. 5) Medicines require very little space for storage and transport. 6) Homeopathic medicines will not produce a disease in other systems of the body. 7) Doses required are very small, few globules or drops or grains of powder which can be imposed tongue of the animal or administered in water. 8) In homeopathic system of medicine there is no blistering, purging or bloodletting or other painful and debilitating procedures, which may reduce the value of animal after recovery. 9) Homeopathic remedies never conflict with analgesics, vitamins, antibiotics, tranquilizers or other physical therapy of the host. 10) Homeopathic drugs can be administered on the basis of symptoms and so detailed diagnostic aids are not required before the initiation of therapy. 11) Homeopathy and allopathy are not in-compatible, as a matter of fact they act synergistically and hastens the cure.
(Shankarappa Bhajantri*; M. R. Jayashanker) Curronspondent author,Ph.D scholar, Dept of AGB Email Id: drshankarbhanjatri@gmail.com Introduction: Genetic improvement of livestock depends on access to genetic variation and effective methods for its utilization. Sexed selection and genomic selection are the modern technologies which could bring about
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cost of the technology is made affordable to small and marginal farmers. The production of a calf with preferred sex is a long cherished dream of dairy farmers. One of the newer developments in the dairy industry is use of sexed Semen. This allows selection of potentially superior females, producing replacement heifers specifically from these animals. Genetic progress could be increased by 15 per cent if sexed semen was used as compared to conventional semen. By natural service or AI using normal semen, probability of getting female calf is about 50 per cent while by using sexed semen the probability of getting calf of desired sex increases to above 90 per cent. Methods of semen sexing Sexing of Spermatozoa can be used as a wonderful tool to alter the sex ratio and thereby to enhance the milk production and to meet the growing demand for milk. Out of the various procedures available for pre and post-fertilization sex determination, the most elegant method of achieving an alteration in sex ratio is to separate spermatozoa into X and Y bearing spermatozoa as the sex of the offspring is determined by the sex chromosome within the spermatozoa. The methods/procedures to separate spermatozoa in to X and Y bearing fractions have been based on differences between each subpopulation on the basis of mass, motility, DNA content, surface charge and sperm cell surface antigenic determinants . Parameter
X Spermatozoa
Y Spermatozoa
Method
DNA
More DNA
Less NDA
Flow Cytometry
Size
Larger
Relatively smaller
Percoll method
Motility
Swim slower
Swim faster
Swim Up
Surface Charge
Migrate to cathode fastly
Sperm Surface
Migrate to cathode rela- Free flow electrophoretively slowly sis
Absence of HY Antigen Presence of HY antigen Immunological sexing
Flow cytometry – Fluorescence activated cell sorting: (FACS) Separation of X and Y chromosome bearing sperm with the accuracy of 85 to 90 per cent by flow cytometric sperm sorting is based on the differential DNA contents between X and Y chromosome bearing sperm which is approximately 3.8 per cent. Flow cytometric sperm sexing plays many important roles in livestock production industries. For example, female cattle are required for dairy industry whereas males are required for beef cattle Industry. In order to reduce cost and maximize the availability of sexed semen straws each straw contain about 2 million sperms while conventional semen contains 10-20 million sperm per straw. Semen is actually sorted one sperm at a time and yield is low.
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Although the sorting process is 90 per cent accurate, approximately half the sperm cannot be sorted because they are damaged or the machine could not determine X or Y. Therefore, 50% of the ejaculate is discarded.
Conception rate with sexed semen Several large scale studies with use of sexed semen in dairy heifers indicate that pregnancy rates are 10 per cent to 20 per cent lower with sexed semen compared to conventional semen. Using information from 39,763 inseminations with sexed semen and 53,718 inseminations with conventional semen, heifer pregnancy rates of 45 per cent and 56 per cent for sexed and conventional semen, respectively, and that 5 to 10 per cent conception rate differences in heifers of all breeds between 2 x 106 sperm/dose of sexed semen compared to 15 x 106 sperm/dose of conventional semen and a reduction in conception rate in Holstein, Jersey, Danish Red by 12 per cent , 7 per cent, and 5 per cent, respectively. The difference in Percentage of heifer calves, Conception rate and number of live sperms/dose for Conventional semen which were 50 per cent, 60 per cent and 15-20Ă—106 respectively
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where as for the Sexed semen values were 90 percent, 48 percent and 2.1×106 ,respectively. Practical Applications of Sexed Semen 1) Produce more female progeny from superior germ plasm. 2) Raising systematic and controlled herd replacement stocks. 3) Targeted and increased milk and meat (buffalo meat) production. 4) Ensure male progeny as herd sires from tom dam-sire crosses. 5) Ensure appropriate progeny when progeny testing young bulls. 6) Establishment of superior heifer supply centre at Govt./institutional/filed level. 7) Control over the birth of unwanted males which is not suitable for rearing (breeding/draught purpose). 8) Use of sexed semen for in vitro fertilization, super ovulation and embryo transfer programs. Limitations on the use of Sexed Semen 1) High cost of sexed semen straw limits affordability to poor/rural farmers. 2) High dependency on Imported sexed semen than indigenously produced. 3) Low concentration of sperm (- 2 million) per straw. 4) Greater sensitivity of sexed semen straw to handling during thawing and AI. 5) Reduced and variability in conception/pregnancy rate could be attributed to selection of breedable females, handling of semen, right time of AI, technical expertise of the inseminator and more intrinsically damage to sperm, early capacitation of sperm, altered gene expression leading to impaired embryo development and mortality. 6) Due to the fragile nature of sexed semen and the use of cc straws, semen handling when thawing, loading, and inseminating is critical. 7) One of the biggest limitations for seed stock breeders is that a relatively small percentage of AI bulls are available as sexed semen. This severely limits the breeder’s options for genetic selection. If sexed semen is used heavily then the amount of genetic diversity may decrease due to the small number of sires available. 8) Risk of over production of offspring from a particular bull (most wanted pedigreed bull). 9) The reduction in conception risks with sexed semen will result in a longer breeding period and consequently in a greater age of first calving. Future challenges 1) Sexed semen has the potential to add significant value in seasonal, pasture-based dairy production systems, both at farm and wider industry levels. 2) It is likely that sexed semen will be used more widely as its fertility performance improves and the efficiency of the sorting procedure increases. 3) To reduce the cost of sperm sexing. 4) Multiple nozzles to sort sperm in different streams to speed up the process. 5) To make the technology available at farmer’s door. 6) Identification and use of sperm surface markers specific for X and Y spermatozoa is an option.
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Future thrust areas of research 1) Deeper understanding on the physiology of X and Y spermatozoa (morphological and functional differences). 2) Sperm cytogenetic: Chemical or immunologic reaction capable of selecting on sex chromosome content. 3) Sperm environment: Hormone or chemical condition resulting in selection of X or Y sperm in the female reproductive tract. 4) Understanding the genomic, transcriptomic and proteomic regulation of X and Y spermatozoa. 5)Simplification of Flowcytometric machine to reduce the cost. 6) Research on sperm sorting procedure to Increase speed, accuracy of separation and volume of sexed sperm yield.
Insight into cancer resistance in elephants could aid human treatment :
They are the largest land animals in the world, weighing up to 14,000 pounds and standing up to 4 meters tall. Given their size, elephants should be highly susceptible to cancer - they have at least 100 times more cells than humans - but they rarely develop the disease. In a new study, researchers shed light on the mechanisms behind elephants' resistance to cancer - information that could fuel knowledge on cancer resistance in humans.
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Overall, the researchers found that cancer mortality rates did not increase with the size or lifespan of a mammal. For example, the cancer mortality rate for elephants was only 4.8%, compared with an 11-25% cancer mortality rate in humans. The team also revealed that elephants possess at least 20 copies of a major tumor-suppressor gene called TP53, while healthy humans only have one copy, with two alleles (gene variants) inherited from each parent. People with LFS only inherit one functioning allele of the TP53 gene, according to the team, putting them at a 90-100% lifetime risk for cancer. The researchers explain that the TP53 gene plays a key role in the response to DNA damage by triggering a form of cell death called apoptosis via the p53 protein. Compared with human lymphocytes, the researchers found that elephant lymphocytes were subject to p53-induced apoptosis at higher rates.
monthly e-Bulletin Published and circulated by Veterinary
Editor: Dean, Veterinary College, Hebbal, Bengaluru Dr. S. Yathiraj (Ex-Officio)
College, Hebbal, Bengaluru.
Associate Editior: Head, Dept. of Vety.& Animal Husbandry Extension Education Dr. K. Satyanarayan (Ex-Officio)
Contact : Dept of Veterinary and Animal Husbandry Extension Education Veterinary College, Hebbal Bangalore email: pashubandhavch@gmail.com Blog: pashubandhavch.blogspot.in
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