Effect of Egg Size on Heat Production and the Transition of Energy From Egg to Hatchling

Abstract

An experiment was conducted to study the effect of egg size on embryo development, heat production, and energy partitioning between egg and hatchling. Small (56.1 +/- 0.12 g SEM) and large (70.0 +/- 0.11 g SEM) hatching eggs were incubated in climate respiration chambers, and eggshell temperature was maintained constant at 37.8 degrees C in both egg weight classes by adjusting machine temperature. Dry matter, ash, protein, and fat contents were determined in albumen, yolk, yolk-free body (YFB), and residual yolk (RY), and carbohydrate contents and caloric values were calculated. To achieve a constant eggshell temperature, machine temperature needed to be set lower from d 15 onward, coinciding with increased heat production in large eggs compared with small eggs. Selective nutrient uptake resulted in higher fat content and lower protein content in RY in chicks that hatched from small eggs compared with large eggs. The respiration quotient in small and large eggs was the same, and embryos in small and large eggs were equally efficient in the transfer of energy from egg to YFB. The surplus availability of nutrients in large eggs was therefore held responsible for the absolute and relative higher weight of RY in chicks that hatched from large eggs compared with small eggs.

Effects of egg size (weight) and age on hatching performance and chick quality of broiler breeder

“…Deeming and Van Middelkoop (1999) reported that as the flock ages, there was more infertility and early embryonic mortality in eggs from Ross 308 compared with Cobb 500. It is well recognized that there is a strong relationship between breeder age and egg weight such that older hens produce larger eggs (Lourens et al 2006). Chick weight increased with advancing age of broilers' breeders as reported by Yildirim (2005) and Christensen et al (2002).…”

Thermal stimulation of Ross®-lineage embryos on a commercial scale

“…According to the literature, increased residual yolk is a sign of overheating (LEKSRISOMPONG et al, 2007), which reaffirms the possibility that non-scheduled variations at inadequate times may negatively affect normal development. In the industry, temperature variability in different regions of the machine is often observed (FRENCH, 2002), since there are eggs of various origins and in different phases of development, in addition to differences in metabolism, oxygen consumption, and size due to breeder hens of different ages (LOURENS et al, 2006;HAMIDU et al, 2007). This study evaluated the development of embryos from Ross ® breeder hens aged between 61 and 63 weeks.…”

Early life experiences affect the adaptive capacity of rearing hens during infectious challenges

“…Incubation occurred in two different climate respiration chambers (CRC), one for each treatment (Lourens et al, 2006). Egg shell temperature (EST) was used as treatment applied to the eggs, as a reflection of embryo temperature (Lourens, 2001).…”