The statistical methods for the estimation of genotype–environment interactions based on the concept of genetic correlation are reviewed and the implications of genotype–environment interactions in selection and in performance testing of genetic stocks discussed. From comparative testing of commercial poultry stocks there is overwhelming evidence for the occurrence of stock–testing station interactions. However, the relative importance of the effects may vary considerably between performance traits and between testing situations. In general, the consequences of genotype–environment interactions appear to be more serious in egg production stocks than in broiler stocks. For laying rate and viability particularly large effects have to be expected.

Natural infections of turkeys with avian paramyxovirus type 3 (PMV-3) result in drops in egg production, respiratory problems, poor egg quality, virus excretion via the respiratory tract and the development of strong antibody responses. The viruses have been discovered in Canada, the USA, UK, France and Ireland. Field viruses were isolated using chicken embryos and identified using haemagglutination-inhibition tests, complement fixation tests, virus-neutralization tests and fluorescent antibody tests. The exact origin and mode of transmission of the virus remain to be elucidated. The epizootiological factors include geographical distribution, time space, age of turkeys at infection and route of natural exposure. The high mortality of young chicks following experimental infections with an English strain of the virus implies that turkey PMV-3 infections could also be a threat to the chicken industry.

The technological advances in the processing and preservation of quail eggs and meat, evaluation of their nutritive values and development of further processed products therefrom are reviewed. The review of egg and egg products covers the physical and chemical composition of eggs, the influence of age and season on egg quality, storage stability of shell eggs and further processed products including pickled and brined eggs. Aspects concerning optimal slaughter age of quails and their processing, yields of carcass and meat, abdominal fat, nutrient composition, preservation and further processed meat products like pickled, tandoori (roasted), fried and smoked quail are also highlighted in this paper.

Genetic improvement in production of commercial layers was examined by comparing production profiles of three strains representing commercial stocks of the two decades between 1950 and 1970, and by considering North American random sample tests for several production traits performed during the period 1970–80 with stocks that are used commercially in temperate climates around the world. Changes in the production profiles indicate commencement of production at an earlier age and increased persistency of egg production after reaching the peak level. Results from the North American random sample tests of multiple trait selected stocks show improvements not only in egg production, but also in egg size, while egg quality and viability have been maintained.

The authors review the main studies of the last 30 years concerning the chemical and nutritional features of sorghum grain. They describe the problems related to the tannins which lower to various extents its metabolizable energy value, palatability and protein utilization for chickens. They also emphasize that the new sorghum cultivars with low tannin content and nutritive value similar to maize really are suitable for use as the only cereal component of commercial poultry diets.

The variable of feed conversion has an intermediate negative correlation coefficient (–0.46) with the performance of a poultry firm's broiler flocks when these were classified as either ‘good’ or ‘bad’. A multiple regression analysis established that cost per pound regressed significantly (F = 700.9, df = 2/97, p < 0.001) on two variables, percentage processed and feed conversion ratio. The model used has promise for providing objective assessments of producer performance and the classification of economic performance of flocks.