The Effect of Broiler Breeder Genetic Strain and Parent Flock Age on Eggshell Conductance and Embryonic Metabolism

Abstract

The effect of genetic strain (Ross 308; Cobb 500) and parent flock age [young (29 wk), peak (Ross = 34 wk; Cobb = 36 wk), postpeak (40 wk), mature (45 wk), old (55 wk), and very old (59 wk)] on eggshell conductance and embryonic metabolism were examined. At each flock age, eggs from each strain were incubated for 21.5 d in individual metabolic chambers to measure embryonic O(2) intake and CO(2) output. From these data, the respiratory quotient (RQ) and metabolic heat production were calculated. Data were analyzed by the GLM procedure of SAS at P < or = 0.05. Neither strain nor flock age influenced conductance. Total embryonic O(2) consumption, CO(2) output, RQ, and metabolic heat production over the entire incubation period were not affected by strain. Daily differences existed between strains for embryonic O(2) intake (1, 7, 16, 17, 19, 20 d of incubation), CO(2) output (1 to 4, 16 to 20 d of incubation), and heat production (4, 7, 16 to 19 d of incubation). Embryos from young, mature, old, and very old flocks produced significantly more total embryonic heat over the entire 21 d (1,712, 1,677, 1,808, and 1,832, respectively) than embryos from peak (1,601) and postpeak (1,693) flocks. Average RQ for the entire incubation period was higher in embryos from mature flocks compared with all other flock ages. Daily differences among embryos from different flock ages were shown for O(2) consumption (all but d 8 of incubation), CO(2) production (all but d 7 and 9 of incubation), and heat output. The results showed that genetic strain and parent flock age influence daily embryonic metabolism, especially during the early and latter days of incubation. These daily differences coincide with the days of incubation having a higher incidence of embryonic mortality; these 2 factors may be related. Further investigation into the relationship between embryonic metabolic heat production and mortality during incubation may lead to the development of specific incubation conditions for different genetic strains and flock ages.

Investigating the Effect of In Ovo Injection of Silver Nanoparticles on Fat Uptake and Development in Broiler and Layer Hatchlings

“…The metabolic rate of layer embryos from the older breeder flock used in the previous study was 30% lower than in embryos produced by the peak breeder flock used in the current work (9 mL * h −1 versus 13 mL * h −1 ) [7]. It has previously been reported that egg shell conductance and porosity decrease as a breeder flock ages [21]. If this is the case, it can be speculated that the decrease in shell porosity possibly reduced the O 2 diffusion capacity of the shell pore system and the resultant hypoxia limited metabolism in the old breeder flock [5].…”

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.…”

Effects of Ascorbic Acid Injection in Incubated Eggs Submitted to Heat Stress on Incubation Parameters and Chick Quality

“…Conductance is the capacity of gas exchange between the egg and the environment, and it is related with water (Campos et al, 2003) and metabolic heat (Hamidu et al, 2007) losses. The higher the egg conductance and the water loss, the higher egg heat loss by evaporation.…”