Compiled & shared by-DR. RAJESH KUMAR SINGH, (LIVESTOCK & POULTRY CONSULTANT), JAMSHEDPUR, JHARKHAND,INDIA 9431309542, rajeshsinghvet@gmail.com
Genetically modified organisms (GMOs)———–
Gene technology today is an important part of modern biotechnology and is used, among other things, to give bacteria, plants and animals new properties. This is possible by inserting a gene from, for example, a bacterium, into a plant or animal (transgenes). In some cases, genes from closely related or the same species are also transferred (cisgenes). The producers develop GMOs for the purpose of giving us vaccines and medicines, more effective aquaculture and agriculture, and cheaper food.
Genetically Modified Chickens———-
Today’s broiler chickens have been bred selectively since the 1950s to produce meat—breast meat in particular—and to produce it quickly. A modern meat chicken weighs up to three kilograms: almost double the size of a chicken from 60 years ago. And their breasts are 80 percent larger. They also manage to reach this size in five weeks, whereas it took a bird in the 50s up to 15 weeks to reach its fully grown (but much smaller) size. Not surprisingly, this accelerated growth leads to health problems and suffering for the animals.
Transgenic Chicken And Their Uses————-
Genetically modified birds are also known as transgenic birds. An organism that has had part of another species’ genome transferred into its own through the techniques of genetic engineering is a transgenic organism. It should be noted that a transgenic organism is also called a chimera. Cisgenic birds are those who obtained genes from birds of the same genus but different species. Transgenic birds however, obtain their genes from animals or organisms of other species. The points to be listed below are the areas where transgenic birds have been successfully made. Chickens (Gallus gallus) are suitable for gene manipulation because, unlike other domestic animals, they mature quickly, and a single bird can have thousands of offspring. Also, foreign genes need to be inserted into one generation, which passes the genes on.
1 Transgenic Birds for Improved Egg Production —————
A major venture in this area is the mass production of egg yolks with antibodies to be used as artificial growth promoters in chickens and other farmed animals since the use of growth-promoting antibiotics is being reduced or eliminated in meat-animal production as a result of having contributed to the worldwide growth of antibioticresistant bacteria . Hens and their eggs are being genetically engineered to be protein and antibody “factories.” They are being used for the following other uses: To make vaccines.• To produce antibodies in eggs that are added to pig feeds to fight off bacterial infections such as E.• coli. To produce growth-promoting antibodies in egg yolks to be fed to farmed animals to increase their• growth rates by disrupting their normal peptide and gut processes, thus, for example, tricking animals who are already full to continue eating. To produce recombinant lactoferrin and lysozyme as alternatives or supplements to growth-promoting• antibiotics and/or antibodies in poultry diets.To produce antibodies to fight cancer in humans.• To secrete human growth hormone to help dwarfs grow taller.• To produce eggs with lower cholesterol for human consumption.• To produce soy isoflavons in eggs sold for human consumption. For example, poultry researchers at the• University of Maryland and the University of Arkansas are experimenting with Japanese quails to see if soy isoflavons can be transferred and accumulated in their eggs. To produce yolk antibodies, specifically, avian immunoglobulin, or IgY, for a range of diagnostic• systems as a substitute for the use of laboratory mammals. As fertile “egg-type” hens‟ eggs carrying “meat-type” chicken cells in order to mass-produce cloned• “meat” (broiler) chickens, and thus do away with the expensive maintenance of broiler breeder flocks. In this program, “certain individuals from the pedigree flocks would be cloned and the genetic material placed into fertile eggs. Cloning companies would culture cells and then place them into the embryo of a fertilized recipient egg forming a chick called a chimera. The recipient fertile eggs could come from flocks like leghorns that produce a large number of inexpensive eggs. When those eggs are hatched, they are broilers” . In a typical condition, eggs also produce a large amount of ovalbumin in their reproductive tract that becomes part of the egg. Transgenic eggs are engineered to secrete other types of protein into the egg so that they can be easily isolated.
2 Transgenic Birds for Improved Meat Production ———–
The whole idea of transgenic birds for meat production is to get the time from chick to market weight down from 42 days to a brief time which is technically feasible e.g. 30days. The days needed to raise a 35- pound tom (male turkeys) today is 38 percent less than it took in 1966. However, today‟s hens require about 33 percent fewer days to reach a 16-pound market weight . The yearly average body weight of 18-week-old toms has continued to rise from 1966 up to 2001. Following this trend to the year 2010, commercial toms should easily achieve a live weight of over 35 pounds by 18 weeks of age. Meanwhile, geneticists were searching for a fat-reducing gene to insert into broiler chickens because selection for fast rapid growth has increased the number of fat cells in these birds . With these and other projects in mind, genetic engineers were eager to manipulate the chicken‟s DNA to make the birds grow larger, leaner, and faster, and to change the shape and composition of their bodies to fit the “value-added,” deboned chicken parts market overtaking the traditional sale of whole birds.
3. Transgenic Birds For Improved Egg And Meat Production ————
Biotech Companies are presently seeking to Bridge the Gap Between Egg Laying and Meat Production in Chickens. Traditional breeding techniques are starting to hit some limits. For instance, when breeders select birds that grow fatter faster, these birds tend to be duds at laying eggs. But what if there was a way to have the best of both worlds, to create a breed that reached market weight in record time, but also had a high egg-laying potential, so breeders could quickly supply farmers with billions of these new super-birds. India has developed a transgenic chicken variety that is fleshier than normal breeds, and can reportedly also be used in the treatment of diseases. This breakthrough research could help boost production in a country where the annual domestic consumption of poultry and poultry products is worth more than 300 billion rupees (US$6.8 billion.)The tool used to genetically modify the chicken was developed by a team of 3 scientists at the Hyderabad-based Project Directorate on Poultry after 2 years of research using a gene of jellyfish and spermatozoa of a specific variety of chicken from the institute. Bhattacharya, T.K., the head scientist said it is ready for commercial use. These chickens can enhance productivity and give a huge quantity of flesh. Also, the transgenic birds can produce up to 300 eggs over 72 weeks, which is more than twice the number of eggs produced by normal varieties of chickens. The institute hatched 263 chicks in its study group, of which 16 were found to be transgenic. The efficiency of the institute’s method of producing transgenic varieties is about 6 percent.
.4. Transgenic Birds For Erythropoietin Production————–
Accordingly, it is an object of the present invention to provide a transgenic bird producing erythropoietin at high concentration levels as well as a method for constructing the same. The present inventors made intensive investigations and, as a result, found that a transgenic bird producing erythropoietin at high concentration levels can be obtained by the method which comprises incubating a fertilized avian egg, infecting the early embryo formed after egg laying, except for the blastoderm stage immediately following egg laying, with a replication-deficient retroviral vector containing a foreign erythropoietin gene and allowing the embryo to hatch. Such finding has now led to completion of the present invention. The bird to be used in the practice of the invention is not particularly restricted but includes those domestic fowls and pet birds which are reared for meat and egg production, for example chickens, turkeys, ducks, ostriches and quails. Among them, chickens and quails are preferred since they are readily available and are prolific layers. The foreign erythropoietin gene to be used in the practice of the invention is not particularly restricted but preferably is a mammal-derived one, more specifically a human-derived one or one derived from a pet animal such as a dog, for instance. For expression thereof in avian cells, the foreign erythropoietin gene to be used in the practice of the invention is preferably connected to an appropriate promoter on the downstream side thereof.
5. Transgenic Birds For Bird Flu Resistance —————
The long-term threat of an avian flu pandemic could be greatly reduced by a project to produce genetically modified chickens that can resist lethal strains of the virus. British scientists are genetically engineering chickens to protect them against the H5N1 virus that has devastated poultry farms in the Far East, with a view to replacing stocks with birds that are not susceptible to influenza. The technique should also offer protection against many other strains of flu with the potential to start a human pandemic, such as the H7 subgroup that was responsible for an outbreak in Dutch poultry in 2003. If chicken populations were to be replaced with transgenic birds that were resistant to flu, it would remove a reservoir of the virus and make it much harder for it to spread to humans and trigger a pandemic. The team, led by Laurence Tiley, Professor of Molecular Virology at Cambridge University, and Helen Sang, of the Roslin Institute, near Edinburgh, has already shown that chicken cells can be protected against flu by inserting small pieces of genetic material. Theresearchers are now ready to begin a similar procedure with eggs and the first experiments are expected within weeks. Any breakthrough, however, will come too late to have an impact on the present outbreak of H5N1. Even if the technique works, it will be several years before it can be used to stock farms and it also faces important regulatory hurdles and a battle to win over public opinion. If these obstacles are overcome and farmers are willing to adopt GM chickens, the entire world stock could be replaced fairly quickly. “Once we have regulatory approval, we believe it will only take between four and five years to breed enough chickens to replace the entire world population,” Professor Tiley said. “Developing flu-resistant chickens has clear benefits for human health and animal welfare, as we wouldn‟t have to slaughter chickens around the world. Chickens provide a link between the wild bird population, where avian influenza thrives, and humans, where new pandemic strains can emerge. Removing that bridge will dramatically reduce the risk posed by avian viruses.” The research team is following three parallel approaches. One involves inserting a working copy of a gene that makes an antiviral protein called Mx, which is defective in many chicken breeds, and should improve their ability to fight off H5N1 and other strains. The second approach is to harness a technique called RNA interference, in which small fragments of the genetic signalling chemical RNA are used to disrupt the workings of the flu virus. By engineering chicken cells to make small RNA molecules that confuse the flu virus, the scientists hope to confer resistance to a wide variety of strains. The third strategy is similar to the second, but involves using RNA molecules as decoys, which trick the flu virus into copying them rather than itself. All three could potentially be incorporated in the same GM chickens.
Besides the transgenic chicken ,Thanks to the work of kinder scientists, however, we can now enjoy chicken without using birds as meat machines. Plant-based meat companies like Gardein, Boca, and Beyond Meat have perfected the taste and texture of chicken but left the cruelty behind. Simply replacing chicken in your diet with one of these alternatives can spare 24 animals each year from a lifetime
