Progress in the selection of production traits in the poultry industry has been dramatic over the past 75 years. Genetic progress has its biological limits and these may be reached in the next 20 years. The poultry industry will need to adapt with more emphasis on the needs of the consumer (e.g. product quality, health and animal welfare), as well as the needs of the breeders/producers (e.g. lower feed costs and higher fertility). These new traits are difficult and costly to measure by conventional genetic selection methods - the application of genomics is a possible solution. Poultry genomics has benefited from the rapid technological advances in the genetics of model organisms and human. A number of resources and approaches are now well established, including genetic markers and maps (both genetic and physical), QTL mapping, comparative mapping, EST and BAC resources. In addition, the next phase of gene discovery - Functional Genomics is underway. How the poultry industry can benefit and get access to these new technologies is discussed.

As is the case with any industrial process, the manufacture of poultry feeds is subject to considerable sources of variation. If requirements for key nutrients are not met, bird performance in the field will likely be negatively affected. As a result, most poultry companies and feed manufacturers establish quality control programmes as a means of reducing risk. Such programmes must be viewed as an integral part of the business structure of any organization. While they may not be considered ′profit centers′ per se, expenses incurred by a quality control programme must be considered investments, and investments are understood to produce economic returns. Procedures to be incorporated in quality control programmes must be selected based on the economic consequences of uncontrolled variation in given parameters, and the cost of monitoring each. Depending on the size and volume of a given feed manufacturing facility, many evaluations will be conducted on the premises, while others (including most in vivo procedures) will be sent to outside specialized testing facilities. Once a budget has been established for a quality control programme, resources should be shifted as needed to address those sources of variation of most immediate concern to the production of high quality feeds.

Broiler breeders are truly caught in a welfare dilemma, because the management practices that are necessary to ensure health and reproductive competence may also result in a reduction in other aspects of welfare. In this paper I review the welfare concerns associated with feed restriction of broiler breeders. Broiler breeders show evidence of physiological stress as well as an increased incidence of abnormal behaviours, and are also chronically hungry. Alternative methods of decreasing feed intake, dietary dilution or the use of anorexic agents, are also discussed. Thus far, all of these methods have proven unsatisfactory in terms of body weight control, and in addition they do not necessarily improve welfare. Emphasis needs to continue to be placed on developing alternatives to, and modifications of, current feed restriction programmes in order to improve broiler breeder welfare. In addition, the use of genetic selection to decrease the need for restriction should be further explored.

Hen egg proteins are desirable ingredients of many foods. Today, eggs are widely distributed in international trade and the egg industry is an important segment of the world food industry. Hen egg proteins have unique functional properties such as gelling, foaming (egg white) and emulsifying (egg yolk) properties. This review describes the recent advances in molecular basis of the development of these functional properties as well as technical development of new approaches for improving the functional properties of egg proteins. A better understanding of structure-function relationship of egg protein functionality in food system will enable us for tailoring food protein for specific uses.

The unilateral avian oviduct is divisible into five functional regions which, moving distally, include the infundibulum, magnum, isthmus, tubular shell gland and shell gland pouch. Each region subserves a variety of functions, which through their interaction give rise to the multilayered albumen, shell membranes and the organic/norganic complex, which comprises the shell. The sequential activity of these structurally diverse regions is a necessary prerequisite for ′normal′ egg formation. The reproductive effort can be influenced by a number of disease processes either directly by virtue of the fact that they alter the ability of the lining cells to synthesise their integral components or indirect by generally compromising bird health. Notable amongst the former are Infectious Bronchitis, Newcastle Disease and Egg Drop Syndrome. All change the quality of the final product in terms of the shape and texture of the shell. In recent years it has become evident that environmental stress has an equally, if not more, important role to play in oviduct disfunction. In the absence of large areas of functional surface epithelium, the eggs laid were structurally defective at all levels from the mammillary layer outwards. As the epithelial layers regenerated, shell quality approximated normality, but never returned to the pre-stress condition.

The process of candling signals amongst other internal defects a variety of inclusions variously classified as blood and meat spots. They are quite specific in their locations; thus blood spots originating from the rupture of ovarian blood vessels at ovulation, are invariably confined to the periphery of the yolk mass, while meat spots now classified according to their composition are confined to albumen. Within the latter they are recognised as tissue rich deposits, the result of oviduct breakdown and/or calcium rich fragments. The latter implies a breach in the barrier provided by the soft shell membranes.

A review is presented of results from research and commercial production of two alternative keeping systems – furnished cages and aviary systems. These systems have gradually evolved through criticism of conventional cage keeping of layers, mainly in North Western Europe, due to the lack of possibilities for birds to perform natural behaviours and to restricted space. They provide birds with nests to lay eggs in, perches to rest on, and litter material to manipulate and dust-bathe in. Experience and development of the aviary are longer than that of furnished cages, the latter existing in wide spread commercial production only in Sweden as yet. However, according to a new EU-directive in 1999, conventional cages may not be used as a new investment from 2003 and not at all from 2012. Birds in both systems may produce well but the aviaries are less predictable due to irregular outbreaks of flock cannibalism, especially in non beak-trimmed medium heavy brown birds, despite offering the birds litter and plenty of space. The furnished cages try to combine advantages of small group size in cages and reduce disadvantages of poor air condition, and sometimes inferior hygiene, in floor-kept hens. They are still subjected to extensive improvements in details of design e.g. to enhance egg quality. Hence, results may vary considerably between models. In order to maintain a stable social order it is probably vital to retain a moderate group size in furnished cages.

The relationships between phenotype and genotype were first described by Mendelian genetics in the case of genes with a major phenotypic effect. The remarkable improvement of biochemical and molecular tools has now made it possible to identify the molecular nature of major genes, and to understand better their mode of action. From a functional point of view, mutations of a given gene can be classified into three groups: loss of function, interference and dominant negative action, and gain of function. From a structural point of view, a large diversity of molecular polymorphisms can be found, the consequences of which depend rather on their position than on their nature. Genetic abnormalities or mutations with obvious morphological effects provide the most didactic examples to understand the genotype-phenotype relationships. The example of sex-linked dwarfism in chicken is described in detail and the present state of knowledge on the molecular identification of major genes in the chicken is reviewed. Finally, a general discussion, based upon examples taken from human genetics and mouse genetics, draws lessons from the study of major genes in order to approach the study of complex phenotypes or genotype x environment interactions.

This paper describes the feed resource bases for the different chicken production systems and its utilisation potentials in Ethiopia. Past attempts made to improve the production and productivity of birds through better utilisation of locally available feed resources are assessed. The merits and demerits of the different feed types through chemical and animal evaluation are reviewed. Finally, future areas of research on the available feed resource base and feeding of chicken are suggested to aid the rational utilisation of locally available feed resources.