Veterinary World Vol.3(5):238-240 REVIEW Use of Assisted Reproductive Technologies for Livestock Development

Genetic improvement of farm animals is a prime concern over the years for researchers. Several reproductive technologies have been employed to achieve this. Assisted reproductive technologies like Artificial insemination, Superovulation, In vitro Fertilization, Embryo Transfer have been introduced to overcome reproductive problems, to increase the offspring from selected female’s and to reduce the generation intervals in farm animals. The progress achieved during the last few years in the assisted reproductive technologies field has been phenomenal. Artificial Insemination (AI) is the most effective method being used for the genetic improvement of animals. Reproductive capacity and efficiency has been improved tremendously since the introduction of artificial insemination. The development of cloning using various cells from the animal body has created opening of a fascinating scientific arena. These technologies have been propounded as saviors of indigenous livestock breeds. These alternative reproductive techniques are available not only for manipulation of reproductive processes but also proven to be powerful tools in curbing the spread of vertically transmitted diseases. The successful reproductive technologies such as AI and Embryo transfer need be applied on a large scale, emerging biotechnogies such as MOET, IVF and Cloning provides powerful tool for rapidly changing the animal populations, genetically. This advanced reproduction technologies will definitely play an important role in the future perspective and visions for efficient reproductive performance in livestock.


Introduction
for successful reproduction and can be performed by close observation of the animal for oestrus signs or Livestock sector is one of the growing industries using teaser bulls or use of ultrasound technique or which contribute major income to the dairy farmers measurement of hormonal levels.The detection of across the country.Today this sector contributes oestrus is somehow not possible in case of buffaloes around 25 % of Agricultural GDP.For the successful rather than cattle due to the common condition called growth of this sector the dairy animal must be 'silent heat' which is more pronounced in former.So, productive in its life term in order to yield maximum regulation of oestrus is one of the potential tools for returns to farmer.Failure of reproduction can leads to overcoming this kind of reproductive problem.great economic loss in livestock industry.The majority Oesturs Synchronization of this loss occurs because cows do not become pregnant during a defined breeding season.High Synchronization of oestrus is one of the ways to reproductive efficiency in livestock is economically a regulate the oestrus signs detection.In oestrus very desirable characteristic but it s suboptimal due to synchronization the manipulation of the bovine oestrus 1) Failure of Oestrus cycle/Anoestrus.2) Infertility 3) cycle results in standing oestrus in majority of animals, Poor detection of Oestrus cycle.within a short period of time.It is a very effective In order to make the animal as better productive method to increase the proportion of animals that are population, the science has given so many novel bred at the beginning of the breeding season.sex of calves with 85%-95% accuracy by sexing sperm There are no. of methods have been followed for (Garner, 2001).Development of an effective and the Oestrus Synchronization Programme.The simple method for producing animals of the desired sex following methods are commonly used in India.
is economically desirable for livestock producers.1) Using PGF2a Injection: Here, two injections of Multiple Ovulation and Embryo Transfer (MOET) PGF2a should be given at 11 days apart in cyclic A cow normally produces only one egg per females.Detection of estrus is not usually required oestrus cycle (which lasts 21 days) and the gestation before or after injections.All cyclic animals will respond period is 40 weeks.On average, a cow produces only 2to the second injection regardless of what stage of the 3 calves in her lifetime.Thus, without intervention, the oestrus cycle they were in when the first injection was rate at which a particularly desirable cow can be used administered.
to improve the genetic status of a herd is slow.Smith 2) Oestrus Synchronization using GnRH-PGF2a- (1988a,b) introduced the concept of MOET and GnRH protocol: In this method, the cyclic animals demonstrated how well designed MOET programmes irrespective of any day of oestrus cycle were subjected could led to increased selection intensity and reduced to GnRH-PGF2a-GnRH protocol of oestrus generation intervals, resulting in improving genetic synchronization.This protocol program calls for an gains.Embryo transfer is now commonly used to injection of GnRH on day 1 followed by an injection of produce artificial insemination sires from high proven PGF2a on day 8 and a second injection of GnRH on cows and bulls (Bondec, 1989) day 10.The insemination recommended on day 11.The Recent advances in techniques for embryo advantage of this program is it encourages oestrus in transplantation are revolutionising the rate of genetic non cyclic females that are atleast 30 days postpartum.
improvement.The essential stages are as follows: 3) Oestrus Synchronization using CIDR: The basic • Donor cows of good pedigree animals are treated protocol involves placing the CIDR (Controlled Internal with hormones (FSH and LH) to increase the number of Drug Release -Progestin impregnated plastic devices) eggs released at ovulation -multiple ovulation (MO).into the vagina for seven days and giving an injection of • Then the cows are artificially inseminated using PGF2a on day 6 of implantation and observing the semen from a proven bull.occurrence of oestrus on day 8.
• After 6-7 days the embryos are flushed out non-Advances in Artificial Insemination surgically, using a catheter placed into the uterus.This It has been practiced on a worldwide scale for is possible because, in cattle, there is a delay in more than half century years.It is still the major embryos becoming implanted in the uterine wall.On technology available for improvement of farm animal's average, 4-7 embryos are collected.reproductive efficiency.The opportunity for genetic • The embryos may then be implanted into improvement through progeny testing and breeding recipient cows whose oestrus cycle is at the correct programmes would be extremely limited without AI for receptive stage-usually as the result of hormonal widespread dissemination of semen from superior manipulation.sires at a reasonable cost.Reports from several • Embryos may be frozen and stored, using species suggest that seminal plasma contains factor techniques similar to those applied to semen, (though that may influence male fertility.These studies are precise control of the regime is somewhat more generally based on comparisons of seminal plasma critical).composition between males of differing fertility or the Significant progress has been made in methods isolation of factors from seminal plasma that facilitate of recovery, storing and implanting cattle and buffalo or inhibit sperm capacitating, fertilization or related embryos (including hormone applications) in several events.Fertility associated antigen in seminal plasma countries of the world.It has been initiated and about appear to be value in predicting small differences in 10 % genetic gains are achieved in cows.In India relative fertility among males.In recent years with the MOET and protocols of ET technology are being technological breakthrough and emerging concepts, standardized in cattle, buffalo, sheep, goat, camel and fertility associated antigen in semen are focused to other species of animals.Embryo transfer has the enhance the fertility.Bulls with identical semen quality potential to bring about genetic improvement twice as in terms of physical assessment vary in actual fertility.fast as AI alone.

The capability to identify bulls on the basis of fertility
Invitro Fertilisation (IVF) potential could result in higher pregnancy rates, The first IVF followed by birth of offspring was leading to larger calf crops.Sperm collection and AI achieved in the rabbit (Thibault, 1954).The first calf have been improved by the advent of sperm sexing, or after IVF was born during 1981.Here, unfertilized eggs selection of sperm carrying an X (Female) or Y (male) are fertilized in the laboratory and cultured for a few enucleated oocyte.The main application of cloning is days until they have developed into early embryos.for expending the use of genetically superior animals.These are then transplanted, using a special long Such animals of high merit, male or female can be syringe, into the uterus of the recipient cows that are at selected for cloning based on any desirable trait, the correct receptive stage of the oestrus cycle.The including milk production, growth, feed efficiency or technique has been greatly improved, now.Obviously, disease resistance. it is possible to choose the egg and semen from high Cloning process involves removing the quality parents.The recovery of eggs from the oviduct chromosomal DNA from mature oocytes and replacing requires surgery.The eggs to be used may be fully it with a cell from the donor animal to be cloned.The mature ones, recovered after ovulation, from the donor cell is then fused with the enulected oocyte and oviduct of a super ovulated cow.activated either chemically or within an electrical pulse to induce activation and reprogramming of the somatic Cloning cell genome to that of an embryonic genome.Animal Cloning is the process by which an entire Reconstructed cloned embryos are then cultured and organism is reproduced from a single cell taken from viable embryos are transferred to synchronized the parent organism and in a genetically identical recipients which carry the live cloned offspring, until manner.This means the cloned animal is an exact parturition.duplicate in every way of its parent; it has the same References exact DNA.
Cloning happens quite frequently in nature.