There are two major types of buffalo: the swamp buffaloes which can be found in most Southeast Asian countries; and the river buffaloes which are found more in India and Pakistan. The river buffaloes, also called the milking buffalo, produce considerable amounts of milk, allowing the Indian dairy industry to contribute 52 percent of the world production of buffalo milk.
There are many reasons for the decline of buffalo populations, foremost of which are: increased agricultural mechanization; increased urbanization, industrialization, and reforestation limiting paddy areas for buffaloes; growing buffalo slaughter rate to satisfy meat demands of a fast-growing population; poor reproductive performance; and lack of proper attention by policy makers and researchers.
The low reproductive efficiency in female buffalo can be attributed to delayed puberty, higher age at calving, long postpartum anoestrus period, long calving interval, lack of overt sign of heat, and low conception rate. In addition, female buffaloes have few primordial follicles and a high rate of follicular atresia.
Buffalo can adapt to harsh environments and live on low quality forage. However, its reproductive efficiency is often compromised by such conditions. Climatic stress depresses ovarian cyclicity, estrous expression, and conception rates. Poor nutrition usually related to seasonal fluctuations in availability and quality of feed, delays puberty and increases the duration of postpartum anoestrus. Management factors such as the system of grazing (free, tethered, or none) and sucking by calves (restricted or ad libitum) also alter reproductive functions. Lack of selected bulls in some regions also affects buffalo reproduction.
Biotechnology can accelerate the improvement of animal production through the introduction of desirable traits (e.g. higher milk yield, or better growth rate), while conventional breeding takes decades to produce major changes.
The international seminar on artificial reproductive biotechnologies for buffaloes primarily aimed to serve as a venue for the exchange in expertise and reproductive technologies on buffalo, as well as the introduction of techniques on somatic cell cloning in dairy cattle. During the seminar, the status and challenges in buffalo production in each country in Asia, as well as its economic and social benefits, were shared and discussed. The activity has contributed much to a better understanding and appreciation of reproductive biotechnology techniques for buffalo, toward enhancing the dissemination and application of the technology in each participating country.
The technical presentations during the workshop considerably covered the use of artificial breeding techniques such as artificial insemination (AI), estrus synchronization, embryo transfer, embryo freezing, in vivo maturation (IVM), in vitro fertilization (IVF), and somatic cell cloning for buffalo. These techniques, which have been used in a limited way in countries where intensive management of buffalo is practiced, allow the distribution of elite buffalo genes and the reduction in generation interval, and provide continued genetic gain and increased production of buffalo meat and milk.
One of the most important areas in improving female reproduction is the ovarian follicular dynamics in buffalo species, the knowledge of which may lead to better synchronization and superovulation protocols as well as embryo production and transfer. Obtaining higher pregnancies from artificial insemination (AI) through appropriate timing within the follicular wave, getting higher yield of eggs or embryos through super-stimulation at appropriate time of the wave, or improving harvest of oocyte for IVM/IVF through ultrasound guided transvaginal (Ovum Pick Up or OPU), are interesting developments and tools in improving livestock production efficiencies.
Artificial insemination (AI). The AI procedure has played a valuable role in facilitating appropriate genetic improvement in animal populations, through widespread use of outstanding males and dissemination of superior genetic material. The offspring will carry 50 percent of male genetic trait. AI can accelerate the introduction of new genetic material by importing frozen semen rather than live animal thus, reducing transport cost. The success of this procedure depends on proper freezing technique, estrus detection, animal management, and nutrition.
Superovulation. Superovulation is done on genetically superior female treated with hormones to induce simultaneous egg production. These eggs can be fertilized with the sperm through in vivo or in vitro methods, and the embryo produced can then be implanted into surrogate mothers (recipients). The donor (superovulated female) should be selected for genetic trait, in the case of buffalo, for milk and meat production and draft power.
In vivo embryo production (IVEP). The technique of IVEP involves multiple ovulation of elite donor, breeding (natural or AI) with top sires, and subsequent embryo collection, embryo conservation, and transfer to estrus/ovulation synchronized surrogate mothers. The serious limitation of IVEP is poor superovulatory response of nearly half of the donors following superovulation treatment. Follicle pool in buffalo is low and a high rate of follicle atresia may contribute to the low outcome of superovulation.
In vitro fertilization (IVF). It is now possible to adopt a fully in vitro system, whereby the immature oocytes are matured through in vitro maturation technique, followed by fertilization with in vitro capacitated spermatozoa and culture of newly formed zygotes in suitable media for development up to the transferable stage. IVF is the most economic and efficient method in large quantity embryo production.
Cryopreservation of buffalo genetic resource. The cryopreservation technique serves as an addition to other existing reproductive biotechnologies in buffalo. In 2001, successful production of buffalo calves after the transfer of vitrified buffalo embryos has been reported. However, cryopreservation of buffalo oocytes by slow freezing procedure was generally met with limited success due to its inherent sensitivity to chilling. Vitrification is an alternative step to freeze oocytes.
Embryo collection. The optimum time for nonsurgical embryo collection is based on the transport rate of embryos in superovulated mothers. Embryo development from superovulated buffalo varies considerably and various stages of embryo may be recovered from the same donor.
Somatic cell nucleus transfer (SNT). Cloning holds the promise of bypassing conventional breeding procedures to allow creation of thousands of precise duplicates of genetically engineered animals in a single generation. Factors affecting the efficiency of cloning in buffalo species involving activation procedures are the age and type of donor cell, the stage of donor cell cycle, and nuclear programming following nuclear transfer. Nowadays, cloning is an efficient technique for producing copies of elite livestock and transgenic animals. However, the overall efficiency of cloning is typically lower than 10 percent, represented by the number of live offspring as a percentage of the number of nuclear transferred embryos. High incidence of developmental abnormalities in cloned animal and pregnancy loss has also been encountered.
In the past two decades, some developing countries in Asia have considerably invested on embryo biotechnology laboratories and skilled manpower toward adopting the technology as an important tool for the faster multiplication of elite buffaloes and their genetic improvement. Conventional in vivo embryo production technology can be effectively used for the production of breeding stock of buffaloes. However, much research still needs to be done in terms of improving the efficiency of embryo transfer, especially in respect to superovulatory response, embryo recovery, embryo freezing, and conception following embryo transfer. Despite some encouraging results, more studies and investigations are required to improve the efficiency of in vitro embryo and calf production so that the same could be used for research in the areas of sexing, cloning, transgenesis, stem cell techniques, and in the overall breeding programs for the genetic improvement of buffalo.
Held in RIAP, Bogor, Indonesia on August 29 - September 1
No. of countries participating: 8 (Cambodia, India, Indonesia, Malaysia, Philippines, Taiwan ROC, Thailand, Vietnam)
No. of papers presented: 18
No. of participants: 60
Co-sponsor: Research Institute for Animal Production (RIAP), Indonesia
Figure 1 Spotted Buffalo at the Indonesian Institute for Science.
Figure 2 Laboratory Demonstration of Buffalo Sperming during the Workshop.
Figure 3 Demonstration of Spermatozoa Sexing Manipulation in Water Buffalo.
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