Effect of broiler breeder nutrition on egg characteristics and chick quality

Production of healthy viable day-old-chicks (DOC) is crucial for health and welfare of the broiler chickens and sustainability in the poultry production chain. Chick quality depends, among others, on the amount and quality of the nutrients stored within the egg, the ability of the embryo to use these nutrients and incubation conditions, which all three (probably) interfere with each other. The pre-natal circumstances are closely regulated by the mother (in ovo). Nutrition of the mother is one of the factors that can have substantial effects on egg composition and development capacity of the embryo and consequently on health, welfare and performance of the offspring. However, mechanisms behind these effects are still poorly understood. Impact of macro-nutrients, like protein and energy, of the breeder hen on egg characteristics and chick quality have barely been investigated. Altering protein and energy intake, mainly during rearing, will affect body composition of the breeder hen. There is proof that a broiler breeder hen uses substantial amounts of body protein and body fat for egg conformation. However, it is unclear whether body composition of the broiler breeder hen affects egg composition and chick quality and physiology. This project aims to improve chick quality of broiler by altering egg and possibly embryo characteristics via maternal nutrition, with a focus on energy and protein intake. Objectives: - To investigate if there is an optimum energy to protein ratio in the diet of the broiler breeder hen for optimal chick quality; - To investigate which breeder characteristics (e.g. body composition, mobilization of body stores, metabolic state), in relation to energy and protein intake, have an effect on egg characteristics and chick quality; Depending on the results of the first experiment: - To determine in which period (e.g. starter, transition, breeding) energy to protein ratio has the largest effect on egg characteristics and chick quality; - To determine which energy source, lipogenic or glucogenic, should be fed to broiler breeders for the highest chick quality. In two experiments different dietary treatments are given to broiler breeder hens from hatch until week 60 of age. Egg size, production and composition will be determined. At several maternal ages, eggs will be incubated to determine effect of maternal dietary treatment on chick quality at hatch and broilers will be followed during the rearing phase.