WORLDS POULTRY SCIENCE JOURNAL, cilt.77, sa.2, ss.313-329, 2021 (SCI-Expanded)
The production quantity of poultry products is increasing in the world economy with every passing day. The increase in chick quality is synonymous with the increase in the number of saleable chicks in terms of the poultry industry. In addition, in order to obtain high-quality products, one should start production with high-quality chicks as well as providing the ideal environmental conditions starting from the first day of incubation. The additive gene effects on chick quality are very low, whereas environmental factors have a large effect. Environmental factors affecting chick quality can be classified as egg storage period and conditions, age and genotype of breeder flock, incubation conditions, incubation types and post-hatch handling. Both quantitative and qualitative methods are used to determine chick quality. The quantitative methods employed include such morphological measurements as chick weight, chick length, leg length, chest circumference, and the diameter of shank. The qualitative methods used to determine chick quality are visual assessment-based methods which are called the Pasgar score and the Tona score. In recent years, the Tona and Pasgar methods have been used frequently in studies carried out with respect to measuring the effects of various environmental practices on chick quality. This paper aims to review the studies carried out concerning chick quality, the factors influencing chick quality, and the determination of chick quality and makes some suggestions for future studies to be conducted on chick quality assessment.