Livestock contribute directly to livelihoods worldwide, providing not only food, but also non-food products, draught power and financial security. Livestock production already accounts for more than one third of the global agricultural GDP in developing countries, and this proportion is expected to increase. The rapidly increasing demand for livestock products, known as the "Livestock Revolution", has created opportunities for improving the welfare of at least some of the nearly one billion poor people who depend on livestock for their livelihoods. However, land degradation, environmental pollution, global warming, the erosion of animal genetic resources, water shortages and emerging diseases are all expected to present challenges to the growing global livestock sector.
Conventional technologies and biotechnologies in livestock have contributed immensely to increasing productivity, particularly in developed countries, and can help to alleviate poverty and hunger, reduce the threats of diseases and ensure environmental sustainability in developing countries. A wide range of biotechnologies are available and have already been used in developing countries in each of the three main sectors of animal sciences, which can be categorized as animal reproduction, genetics and breeding; animal nutrition and production; and animal health.
In animal reproduction, genetics and breeding, artificial insemination (AI) has perhaps been the most widely applied animal biotechnology, particularly in combination with cryopreservation, allowing significant genetic improvement for productivity, as well as the global dissemination of selected male germplasm. Complementary technologies such as the monitoring of reproductive hormones, oestrus synchronization and semen sexing can improve the efficiency of AI. Embryo transfer provides the same opportunities for females, albeit on a much smaller scale and at a much greater price. Molecular DNA markers can also be used for genetic improvement, through marker-assisted selection using markers located beside genes of interest, as well as to characterize and conserve animal genetic resources. Use of most molecular marker systems depends on the polymerase chain reaction (PCR), which is an important technique for amplifying specific DNA sequences.
AI is practiced at some level in most developing countries. Its use is primarily in dairy cattle and peri-urban areas where complementary services including milk marketing are available. The high cost of liquid nitrogen for the cryopreservation of semen often restricts AI use far from cities. AI is usually used for crossbreeding with imported germplasm rather than for superior local genetics, due to the paucity of animal identification, recording and evaluation programmes. This lack of a system for the identification of superior animals precludes (along with lack of technical capacity) the use of more advanced technologies, such as embryo transfer or marker-assisted selection. Molecular biotechnologies in the area of animal reproduction, genetics and breeding have generally been limited to genetic characterization studies, usually through international cooperation.
Biotechnologies for animal nutrition and production are often based on the use of micro-organisms, including those produced through recombinant DNA technology. Fermentation technologies are used to produce nutrients (such as particular essential amino acids or complete proteins) or to improve the digestibility of animal feeds. Microbial cultures are used to increase the quality of silage or to improve digestion, when fed as probiotics. Recombinant bacteria have been developed to produce specific enzymes and hormones that improve nutrient utilization, which can increase productivity (e.g. somatotropin) and/or decrease environmental impact (e.g. phytase). Fiber-degrading enzymes have also been used to increase animal productivity and decrease environment pollutants.
Although data are scarce, amino acids and enzymes appear to be the most prominent and widespread nutrition-related biotechnology products used in developing countries. India and China have developed local industries to produce them. Various factors have limited the use of many other biotechnologies. For example, silage production is not common, thus precluding the use of microbial cultures. The uptake of recombinant somatotropin has been affected by low public acceptance, the lack of adequate and good quality feed and the low genetic potential of animals in developing countries. Fermentation of lignocellulosic materials to improve the quality of crop residues and forages has not been very effective.
Biotechnologies are used in animal health to increase the precision of disease diagnosis as well as for disease control and treatment. Monoclonal antibodies are used in immunology-based diagnostic methods, including enzyme-linked immunosorbent assays and radioimmunoassays. These methods may not allow the distinguishing of vaccinated from infected animals, so molecular biology approaches that detect specific DNA sequences are now preferred. Vaccination is also an indispensable method for maintaining animal health, and recombinant vaccines offer potential advantages over traditional vaccines in specificity, stability and safety. In addition, the sterile insect technique (SIT), usually applied as part of an area-wide integrated pest management approach, is used to improve livestock health within a certain geographical area by controlling insects that cause or transmit specific livestock diseases.
In animal health, molecular-based serological techniques are widely used in developing countries. PCR-based diagnostics are increasingly used to allow early diagnosis of diseases, but their use is mainly restricted to the laboratories of research institutions and larger governmental diagnostic laboratories. Vaccination has been widely used as a cost-effective measure to control infectious diseases, as exemplified by the soon-to-be-confirmed eradication of rinderpest. However, few recombinant vaccines are being produced commercially, and their use in developing countries is negligible. SIT has played a vital role in the eradication of the tsetse fly population in Zanzibar and in the control of screwworms in several countries.
For more information, see Current status and options for livestock biotechnologies in developing countries [ - 273 KB], prepared for the FAO international technical conference on Agricultural Biotechnologies in Developing Countries (ABDC-10) that took place 1-4 March 2010 in Guadalajara, Mexico.
Page Last Updated: July 2010