The poultry industry in Korean has expanded considerably during the last 15 years. While the number of chicken farms of commercial scale has decreased steadily during the period average farm size increased rapidly. Though the gross national product per capita increased 4.5 folds during ten years period, consumption of chicken meat, like other meats, recorded only 2 folds increase during the period. When domestic market for chicken meat had been open for two years on the basis of minimum market access quotas, importation remained at levels below the quota during the first one and half years. Nevertheless, during the last six months and thereafter, chicken meat importation recorded a steep increase, threatening the domestic industry. Poor productivities of the commercial chicken farms might be the main cause for the inferior competitiveness. For the sustainability of the industry some suggestions were made.

Chicken has been one of the most useful animals for life. They have been not only one of the most economical and adundant sources of valuable nutrients, but also the very good experimental animal to develop modern sciences. In Japan, eggs laid by the chickens have long been good sources of cash income for farmers and in many cases even for Samurais. Although nearly 50 millions of chickens were raised and they were of considerable importance in Japanese agricultre before the World War II, the industrialization or specializatin started after the War, Substantiallysince the 1960s. Among other spcies of poultry then chickens, ducks and Japanese quails are of some importane in Japan. Duck meat is often used in various cuisines at higher class restaurants and Japanese quail eggs are widely used. Hower those those species of commpared with chickens.

The mechanically deboned chicken meat(MDCM) has several limits in using for in using for in processed meat products as a main material because of poor color and textural properties, chance of microbial contamination and lipid oxidation. There has been a growing interest all over world in the application of MDCM to the surimi process. The surimi made from MDCM contains a high concentration of myofibrillar protein since this processing involves repeated washing processes with an aqueous solution in order to remove heme pigments, fat and other undesirable substances. The quality of the surimi made from MDCM is affected by various processing factors, such as kinds of wash solution, ion strength, washing cycle, temperature, pH changes, composition, part of muscle, particle size, and rigor state etc. A number of researchers havee investigated the effect of the various washing conditions on the properties of surimi gels. A fuller information of all the factors affecting surimi processing and gel formation by heat-induced gelation has not been known yet.

The consumer demands for quality of meats has become diverse in recent years. The present paper describes mainly the technology to improve the broiler meat quality with special reference to reducing fat contents in edible meats which is the heart of the quality constraints. Abdominal fat deposition in broilers was reduced by feeding of medium-chain triglycerides(MCT), suggesting MCT feeding is useful to produce broiler meat with low fat content. A phase feeding system to aim at improving meat quality that is mainly comprised with partial replacement of dietary protein into phase during 4∼6 weeks increased edible meat yields and reduced abdominal fat deposition and fat contents in breast and thigh meats. Whiteness of fat tissue was intensified by feeding beef tallow or lard in place of yellow grease. Feeding Phaffia yeast containing astaxanthin increased redness of breast and thigh meats and improved visual appearance of meats which may be preferential for consumers. Feeding fish oil reduced abdominal fat deposition and increased EPA and DHA contents of fat tissues. These procedures could be used for manipulation of meat quality to meet consumer demands.

Hen's eggs have been regarded as one of the best animal bioreactors to produce biologically active peptides originated from many organisms including human. Despite the last decade's efforts to produce transgenic chicken for any commercial purposes, the results so far reported are very disappointing, indicating that hen's eggs are very difficult to crack for transgenesis. Comparatively large female gamete with enormous amount of yolk may be one of the major obstacles in achieving a similar feat to those of other vertebrate species including mouse, sheep, fish and frog. The delay or less efficiency evidenced may instruct to try an alternative way of gens transfer into chicken egg. Sperm-mediated gene transfer is one of them, and may require a great deal of understanding of mechanisms involved in early fertilization and embryonic development. In other animals where the technique was successful, basic mechanisms have been well studied and established only by painstaking efforts for decades. This paper discusses the accumulated knowledge on early fertilization mechanism in the chicken and how can this information be utilitzed to find the alternative gene transfer in making transgenic chicken.

In recent years, numerous researches have been carried out in author's laboratory to develop several kinds of methods for producing transgened chicken, leaving a lot of new findings. Some of them are very useful to search for new approaches necessary to improve the efficiency of hatchability and the survival rate of developing trasgened embryos. The results obtained hitherto might be summarized as follows: (1) foreign gene(Lac Z/ Miw Z) introduced into blastodermal cells of developing embryos was successfully transferred to embryos, leading to the production of primordial germ cells(PGCs) carrying foreign DNA. However, hatched hickens failed to show the incorporation of introduced gene into the gonads. (2) When foreign gene was introduced into germinal crescent region (GCR), the gene was also efficiently incorporated into germ cells, resulting in the production of transgened chickens(offspring) which produced fruther offspring having foreign gene in the gonads. In this case, 2nd and 3rd generations of chickens were obtained through the reproduction of transgened birds. (3) In another way, the gene was injected into blood vessels of developing embryos at stage 13∼15, creating PGCs having foreign gene, and produced some transgened chickens. In this work, the PGCs were transfered between embryos, resulting in the production of transgenic chickens. (4) in these experiments, PGCs were effectively employed for producing transgenic birds, developing some kinds of chimeric chickens from homo- or hetero-sexual transfer of the PGCs from embryos. This means that the gonads from donor PGCs developed in some degree to the stage of hatching. However, these gonads showed slightly abnormal tissues similar to ovotestis like organs through histological examination. (5) Avian Leukosis Virus(ALV) induced B cell line(DT40) successfully carried foreign genes into chicken embryos, suggesting the possibility of the cells as a vector in this field of study in the future. (6) Inter-embryonic transfer of the PGCs also gave us some.

Coccidiosis, an intestinal infection caused by intracellular protozoan parasites belonging to several different species of Eimeria seriously impairs the growth and feed utilization of livestock and poultry. Due to complex life cycle of organism and intricate host immune responses to Elmeria, coccidia vaccine development has been difficult. Understanding of basic imunobiology of pertinent host-parasite interactions is necessary for the development of novel control strategy. Although chickens infected with Eimeria spp. produce parasite-specific antibodies in both the circulation and mucosal secretions, antibody mediated responses play a minor role in protection gainst coccidiosis. Rather, increasing evidence show that cell-mediated immunity plays a major role in resistance to coccidiosis. T-lymphocytes appear to respond to coccidiosis both through cytokine production and a direct cytotoxic attack on infected cells. The exact mechanisms by which T-cells eliminate the parasites, however, remain to be investigated. Since it is crucial to understand the intestinal immune system in order to develop an immunological control strategy against any intestinal immune system in order to develop an immunological control strategy against any intestinal diseases, this presentation will summarize our current understanding of the avian intestinal immune system and mucosal immune responses to Eimeria, to provide a conceptual overview of the complex molecular and cellular events involved in intestinal immune responses to enteric pathogens.