High Environmental Temperature Increases Glucose Requirement in the Developing Chicken Embryo

Abstract

Environmental conditions during the perinatal period influence metabolic and developmental processes in mammals and avian species, which could impact pre- and postnatal survival and development. The current study investigated the effect of eggshell temperature (EST) on glucose metabolism in broiler chicken embryos. Broiler eggs were incubated at a high (38.9°C) or normal (37.8°C) EST from day 10.5 of incubation onward and were injected with a bolus of [U-13C]glucose in the chorio-allantoic fluid at day 17.5 of incubation. After [U-13C]glucose administration, 13C enrichment was determined in intermediate pools and end-products of glucose metabolism. Oxidation of labeled glucose occurred for approximately 3 days after injection. Glucose oxidation was higher in the high than in the normal EST treatment from day 17.6 until 17.8 of incubation. The overall recovery of 13CO2 tended to be 4.7% higher in the high than in the normal EST treatment. An increase in EST (38.9°C vs 37.8°C) increased 13C enrichment in plasma lactate at day 17.8 of incubation and 13C in hepatic glycogen at day 18.8 of incubation. Furthermore, high compared to normal EST resulted in a lower yolk-free body mass at day 20.9 (−2.74 g) and 21.7 (−3.81 g) of incubation, a lower hepatic glycogen concentration at day 18.2 (−4.37 mg/g) and 18.8 (−4.59 mg/g) of incubation, and a higher plasma uric acid concentration (+2.8 mg/mL/+43%) at day 21.6 of incubation. These results indicate that the glucose oxidation pattern is relatively slow, but the intensity increased consistently with an increase in developmental stage of the embryo. High environmental temperatures in the perinatal period of chicken embryos increased glucose oxidation and decreased hepatic glycogen prior to the hatching process. This may limit glucose availability for successful hatching and could impact body development, probably by increased gluconeogenesis from glucogenic amino acids to allow anaerobic glycolysis.

High Incubation Temperature and Threonine Dietary Level Improve Ileum Response Against Post-Hatch Salmonella Enteritidis Inoculation in Broiler Chicks

“…We strongly believe that such protective effect might not be due to the inflammatory axis only, but might also involve complex metabolic issues. For instance, accelerated yolk sac absorption may have resulted from the faster metabolism of chicks during incubation in high temperature [ 13 ] and from increased glucose needs before hatch and during the hatching process [ 25 , 26 ]. Yolk sac absorption is determining to the proper development of the gastrointestinal tract in the chick in the first 48 h after hatch [ 27 ], the same age used in the present study for SE challenge.…”

Quantifying resilience of humans and other animals

“…One problem is that the conditions that facilitate highly efficient production of meat, milk, and eggs tend to come at a cost in the animals’ resilience ( 16 – 19 ). It is becoming clear that not only genetic make-up ( 17 , 20 ) and feed composition ( 21 ) but also early-life conditions supporting the development and expression of important behaviors and the establishment of social relationships ( 22 , 23 ) have an impact on health and survival ( 24 – 26 ). However, we lack a quantitative understanding of how these multiple factors interact to shape animal resilience.…”

The Role of Incubation Conditions in the Onset of Avian Myopathies

“…The longer time that these chickens had to reach feed probably affected satellite cells. Even though the eggshell temperature was not measured in that experiment, it is known that machine temperatures higher than 37.6 • C after 15 days of incubation could cause overheating in the embryos (Molenaar et al, 2013), and this slight overheating could explain the effects on live performance observed in this experiment.…”

“…The differences in the responses observed between the two experiments discussed here are related to the length of exposure to higher temperatures (3 days vs. 12 h), and the timing of application of the heat stress (14 to 18 days vs. 18 to 21 days). Chicken embryos respond differently to heat stress (Molenaar et al, 2013) and hypoxia (Crossley et al, 2003) depending on timing during embryo development, being more critical and deleterious for muscles during the last phase of incubation (Hartley et al, 1992;Christensen et al, 2007;Boleli et al, 2016;Halevy, 2020).…”