Affecting Factors of Egg Weight

Received : 22/07/2019 Accepted : 11/11/2019 In layer sector, egg weight is always an economically important feature and has a critical impact on consumption due to various preferences. The purpose of this article is to review some researches on the factors affecting egg weight. Laying hens genetically have an average egg weight, but on this trait live weight, feeding and lighting programs also have an important effect. In order to achieve optimal egg weight, non-genetic factors can be controlled by egg producers. Because there is a positive genetic correlation between body weight at first egg and egg weight, one of the important factors that affects egg weight is the hen’s body weight at first egg. Hens had low body weight at first egg produce small eggs. Hens are sensitive to light and dark; this phenomenon has a significant effect on number of produced egg and egg weight. Energy, lipid, protein and amino acid levels of feed have effects on egg weight. As a result of the advances in molecular genetics recently, researches have been carried out to elucidate the genetic basis of egg weight. In addition, this review is including information which researches on the relationship between egg weight and genetic structure of chickens.