By Dr Chike Ugwene

Consumption of poultry meat and eggs is increasing steadily moving from a global total of 85 million tonnes in 1992 to 117 million tonnes in 2000 (Executive Guide to World Poultry Trends, 2001,). Biotechnology has provided good tool for breeders to select for and monitor the age at sexual maturity, rate of lay before and after moult, livability in the growing and laying house, egg weight, body weight, feed conversion, shell colour, shell strength, albumen height, egg inclusions (blood and meat spots) and temperament and traits affecting the productivity of the parent. Egg production per hen housed will continue to be the single most important trait under biotechnological selection. However, the emphasis has been shifting from peak rate of lay to persistency of lay.

Animal Production.

A lot has been achieved by the application of biotechnology in animal production. Notable among these achievements is the production of Bovine Somatotropins (BST) through genetic engineering. Bovine somatotropin, a bouvine growth hormone, is a natural protein produced in the pituitary glands of cattle. It helps direct the energy in feed to meet the animals needs for growth and milk production. BST is produced biotechnologically outside the animals' body by genetic engineering processes. When the bacterium, plasmid cut with restriction enzymes is injected into the somatotrop in gene of animal cell, BST is produced. Supplementing BST to the diary cow feed increases feed consumption and milk production. BST directs more of the additional feed towards increasing milk production than to body maintenance.

Porcine somatotropin (PST) has also been produced by the biotechnological processes similar to that described for BST. Porcine Somatotropin given as a supplement increases litter size, reduces the time needed for pigs to reach market weight, improves feed efficiency and reduces carcass fat production.

There has been recent advances made in the areas of embryo splitting (cloning) in livestock production. This has been successfully carried out in cattle and swine. In a transgenic pig, while normal in appearance the boar contains a new gene composed of the mouse metallothionin promoter or regulator fused to the bovine growth hormones structural genes. This gene transmitted by the boar, causes elevated levels of growth hormone in the blood and results in a 10-15% increase in growth rate. The transgenic pigs are also more efficient in feed conversion to the body weight and have significantly less body fat. Nuclear fusion which is the union of nuclei from two sex cells (sperm and egg) has been biotechnologically achieved in laboratory animals but not in larger domestic, farm animals. Also in the area of vaccine production, through the use of biotechnology a lot more broad spectrum vaccines to take care of more than one strain of diseases agent has been achieved.

Even in human beings, gene therapy which involves inserting genes into a patient's cells to treat or cure certain diseases has been made possible through application of biotechnology. In 1980 in USA,  a girl with a hereditary disorder of the immune system had some of her  white blood cells removed, genetically altered, then transfused back into her blood stream so as to produce the needed antibody. This system was also adopted to treat advanced melanoma (skin cancer), immune deficiency disease etc. There was also a break-through in the development of embryo transfer technology which increased the rate of milk production in dairy cattle. The application of biotechnology recorded achievement in the area of antibiotic production for use in animal feed. Isolates of micro organisms were obtained and developed which proved effective against a wide range of diseases.

Plant Production.

Similarly, the application of biotechnology in plant production has recorded good results.

Tissue culture methods have been employed in genetic improvement of cocoa by developing haploid plants by implementing a method of micro  propagation using organogenesis (embryogenesis) and by developing methods that will permit the storage and free interchange of cocoa germ plasma using simple methods of in vitro conservation.

For the musaceas (bananas and plantains) there was production of clones that are tolerant or resistant to plantain diseases. Tissue culture techniques are adopted to obtain somaclonal variation and micro- propagation of' individual that shows desirable characteristics especially resistance to diseases- Different variants have been obtained and are being planted in USA.

There has been biotechnological research to develop tropical root and tuber crops such as cassava (Munihot esculenta), sweet potatoes (Ipemea batatas), cocoyam (Xan-thosoma spp) and  true yam (Discorea spp). The genetic diversity of these species has been studied in Central America as well as in other tropical regions. Presently, at least six clones of every introduction are being maintained in vitro. The results are very satisfactory. Virus-free potato plant material was successfully produced by apical meristtem techniques.

Chemotaxonomy study of the associative bacteria attaching to the root surface of rice plant and contained within the rhizosphere indicated a positive relationship between rice and nitrogen fixation bacteria.

This biotechnological breakthrough has reduced the fertilizer requirements on rice production which has a major impact on Thailand economy.