{"id":278,"date":"2016-11-15T09:06:07","date_gmt":"2016-11-15T03:36:07","guid":{"rendered":"https:\/\/babrone.avfu.ac.in\/blog\/?p=278"},"modified":"2018-11-10T09:46:50","modified_gmt":"2018-11-10T04:16:50","slug":"biotechnological","status":"publish","type":"post","link":"https:\/\/babrone.avfu.ac.in\/blog\/?p=278","title":{"rendered":"Biotechnological interventions in livestock sector to increase productivity and to combat diseases"},"content":{"rendered":"

Biotechnology can be defined as any technique that uses living organisms or substances from such organisms to make or modify a product, to improve plants or animals or to develop microorganisms for specific purposes.<\/span><\/span> It is one of the frontier areas of scientific development in the world today. Advances in the field of biotechnology catered to a wide area of science viz., Agriculture, Animal Sciences, Environmental Science, Food Science, Medicine etc. This sphere of science is increasingly becoming sustainable means of improving livestock production by influencing animal health, nutrition, reproduction and animal products. <\/span><\/span><\/span><\/p>\n

The major challenge faced by animal production is to provide society with food products that meet their evolving nutritional requirements, within specific economic and environmental constraints. According to FAO, 70% of world population will be in hunger in around 50 years from now (2060). It has been reported that the world human consumption for the animal protein is 29 g per capita daily (or 10 kg per capita consumption). However, the trend toward increased per capita demand for foods of animal origin is occurring primarily in developing countries (80% of world population).<\/span><\/span><\/p>\n

Livestock production is expected to grow tremendously in line with the projected demand for production by influencing animal health, nutrition and animal products. Therefore, the methods of livestock production must be changed to allow for efficiency and improvement in productivity. Biotechnological research is important in order to respond to the pressure of producing more food from animals to cater the food requirement of the ever-growing human population. Biotechnology has the potential to improve the productivity of animals by increasing growth, carcass quality and reproduction, improving nutrition and feed utilisation, improving quality and safety of food, improving health and welfare of animals and reducing waste through more efficient utilisation of resources. The biotechnology of livestock production is growing faster than any other sectors and by 2020 livestock is predicted to become the most important agricultural sector in terms of value-added commodity. <\/span><\/span><\/p>\n

Biotechnology in animal physiology and nutrition<\/b><\/span><\/span><\/p>\n

Animal nutrition has provided one of the greatest challenges to animal production with limitations arising from both quality and quantity. A large proportion of animal feeds are fibrous with varying levels of digestibility and nutritive values. Animal nutritionists have developed technology to improve nutritive value for feeds, enhance digestibility and acceptability, and removal of anti-nutritive factors from feeds especially for ruminant animals. Apart from the technology<\/span><\/span> <\/i>targeted on feeds, the manipulation of rumen microbial population through alkali treatment, microbial balancing and genetic manipulations are probably the most reliable means of enhancing degradation of low quality feeds. <\/span><\/span><\/span><\/p>\n

Lignin has been identified as the main cause of difficult digestion of fibrous material. A potent lignase enzyme produced by the soft-rot fungus (<\/span><\/span>Phanerochaete chrysosporium<\/i><\/span><\/span>) that causes a high degree of depolymerisation of lignin is now available. Although the lignase levels produced by the fungi cannot meet the requirements for commercial treatments of straw, recombinant DNA technology has been claimed to have the potential to modify lignase genes and proteins to increase efficiency and stability considering that the lignin gene has already been cloned and sequenced from <\/span><\/span>P. chrysosporium.<\/i><\/span><\/span><\/span><\/p>\n

Manipulation of digestive tract environments which includes mainly the rumen in ruminants and intestinal tract in monogastrics using prebiotics and probiotics has been reported to be beneficial and effective in increasing the availability of nutrients to the animals. The main focus in the rumen is the manipulation of microbial flora population and type. Attempts have been made to introduce transgenic bacteria in the rumen environments to increase efficiency of rumen fermentation. Inactivation as well as detoxification of anti-nutritive factors in plants such as protease inhibitors, tannins, phytohaemaglutinins and cynogens mainly in legumes can also be done using transgenic bacteria.<\/span><\/span><\/p>\n

Bovine somatotropin (a growth hormone), also called BST, has been produced with the help of a bacteria through recombinant DNA technology. Injection of BST in cows every two weeks increases milk production by about 20 per cent. Even though scientists consider BST very safe and cost-effective, it has been banned in some European countries. This is partly because of current milk surpluses and partly because of the risks inherent in DNA recombinant technology.<\/span><\/span><\/p>\n

Biotechnology in animal reproduction<\/b><\/span><\/span><\/p>\n

Artificial insemination is by far the most widely used biotechnology<\/span><\/span> <\/i>in animal reproduction and has been reported to result in genetic progress that is four times better than natural mating. Artificial insemination (AI) and embryo transfer (ET) are probably the most popular methods that have been adopted in developed and developing livestock industries. Supporting technologies that have increased the efficiency of AI and ET include micromanipulation of gametes and embryos for splitting, sexing, cloning, gene transfer, cryo-preservation of embryos, <\/span><\/span>in-vitro<\/i><\/span><\/span> maturation, fertilisation and culture (IVFMC) as well as genome analysis. The recent advances in biotechnology in reproduction also include production of transgenic animals and cloning.<\/span><\/span><\/span><\/p>\n

Artificial insemination (AI):<\/b><\/i><\/span><\/span> <\/i>Especially since the development of efficient semen freezing methods, AI has become the most widespread biotechnology applied to livestock and especially cattle production. <\/span><\/span>No other technology in agriculture except hybrid seed and fertilizer use has been so widely adopted at a global scale as AI. Progress in semen collection, dilution and cryopreservation now enables a single bull to be used simultaneously in several countries for up to1, 00,000 inseminations a year.<\/span><\/span> By allowing for the widespread use of small numbers of elite sires, AI has had a dramatic impact on selection intensity. In addition, AI has allowed for the implementation of the progeny-testing scheme prevalent particularly in dairy cattle production, and which has had a major impact on the improvement of the herd by increasing the accuracy of selection despite the associated increase in generation interval. <\/span><\/span><\/span><\/p>\n

Embryo transfer technology (ETT):<\/b><\/i><\/span><\/span> <\/i>Although presently not economically feasible for commercial use on small farms, embryo technology can greatly contribute to research and genetic improvement of local breeds. Advances in this area are mainly applicable in cattle. There are two procedures presently available for production of embryos from donor females. One consists of superovulation, followed by AI and then flushing of the uterus to gather the embryos. The other, called <\/span><\/span>in vitro<\/i><\/span><\/span> fertilization (IVF) consists of recovery of eggs from the ovaries of the female then maturing and fertilizing them outside the body until they are ready for implantation into foster females. The principal benefit of embryo transfer is the possibility to produce several progeny from the female, just as AI produces many offspring from one male animal.<\/span><\/span><\/span><\/p>\n

Oocyte harvesting (OPU), in-vitro oocyte maturation (IVM), in vitro fertilisation (IVF):<\/b><\/i><\/span><\/span> <\/i>While the number of embryos that can be obtained from a cow \/ year using multiple ovulation and embryo transfer (MOET) is on an average limited to the order of 20 or less, the development of OPU in conjunction with IVM and IVF increases by at least 5-fold. Moreover, OPU can be applied to pregnant animals as well as prepubertal animals. The impact of these methodologies on genetic response operates through the same channels as MOET, i.e. increase of selection intensity on the female side and increase of selection accuracy on the male and female side.<\/span><\/span><\/span><\/p>\n

Nuclear transfer or embryo cloning:<\/b><\/i><\/span><\/span> <\/i>The transfer of totipotent nuclei in enucleated oocytes theoretically allows for the production of large numbers of identical twins or \u201cclones\u201d. This opened the prospective to affect genetic response in a variety of ways including selection intensity, selection accuracy and generation interval. Initially, the sources of totipotent nuclei were blastomeres. Despite the potential use of first as well as higher order generation blastocysts as nuclei donors, the size of the clones has remained very small. The recent generation of totipotent embryonic stem \u201cES\u201d-like cells might lead to a considerable increase in the efficiency of embryo cloning.<\/span><\/span><\/span><\/p>\n

Sex selection:<\/b><\/i><\/span><\/span> <\/i>The use of sexed semen alters the sex ratio in favour of either sex. It is a great advantage for the dairy industry for producing replacement heifers. The availability of sexed semen in dairy cattle has been eagerly anticipated for many years, and recent developments in fluorescence-activated cell sorting have brought this technology to commercial application. <\/span><\/span>Recent improvements in flow cytometric sorting now allows for the effective separation of viable X and Y-bearing sperms. While the numbers of cells recovered are incompatible with conventional AI practices, they are sufficient when combined with IVF techniques. This might become the method of choice to generate embryos of a desired sex. Embryo sexing can also be achieved by micro-biopsy and sex determination using polymerase chain reaction (PCR) amplified Y-specific sequences. This approach, however, is economically only justified in very exceptional circumstances.<\/span><\/span><\/span><\/p>\n

Gamete and embryo cryopreservation:<\/b><\/i><\/span><\/span> <\/i>Most methods described are only effective when used in conjunction with gamete and embryo freezing methods. In addition cryopreservation plays a crucial role in conservation programmes aimed at maintaining genetic diversity.<\/span><\/span><\/span><\/p>\n

Biotechnology and Animal Production<\/b><\/span><\/span><\/p>\n

Based on the central theory, \u201c<\/span><\/span>P = G + E\u201d<\/i><\/span><\/span>, that is, the <\/span><\/span>Phenotype <\/i><\/span><\/span>of an animal reflects its intrinsic genetic aptitude or <\/span><\/span>Genotype <\/i><\/span><\/span>as expressed in a given <\/span><\/span>Environment<\/i><\/span><\/span>, animal breeders have adopted a two-pronged approach towards improving the quality of their production. On the one hand, they have learned to master the environmental component by improving animal husbandry and nutrition practices, disease prophylaxis and treatment. On the other hand, artificial selection has allowed to continuously improve the genetic make-up of domestic species. Biotechnology has been adopted in the battery of tools aimed at improving both the <\/span><\/span>nurture <\/i><\/span><\/span>(<\/span><\/span>E<\/i><\/span><\/span>) as well as <\/span><\/span>nature <\/i><\/span><\/span>(<\/span><\/span>G<\/i><\/span><\/span>) components of the equation. Applications of biotechnology to improve the <\/span><\/span>environmental <\/b><\/span><\/span>component include:<\/span><\/span><\/span><\/p>\n