Heat-stressed Japanese quail (Coturnix coturnix japonica) can experience blood acid-base disequilibrium and electrolyte disregulation. This disequilibrium may influence egg-shell quality, enzyme functions, and synthesis of tissue proteins. To determine effects of multi-generation heat stress on Japanese quail, the following treatments were applied (1) control (TN, non-sibling random mating at thermoneutral temperature [22.2°C]); (2) thermoneutral siblings (22.2°C, TNS); (3) heat stress (HS, non-sibling random mating at 31.1°C); and (4) heat stressed siblings (HSS, siblings of TNS with high feed conversion ratios (FCR), 31.1°C). Body weights (BW), blood gases, and electrolytes of quail were measured during the first 4 hours (acute) and after 3 weeks (chronic) of heat exposure (31.1°C) in generation 10 of the above-mentioned treatments. Statistical significance was determined at P ≤ 0.05. Models included treatments, length of exposure, sex, and their interactions. Results showed that acute and chronic heat stress at 31.1°C did not have a clear effect on blood electrolytes, acid-base regulation, and oxygen transport. Across treatments, sexes, lengths of exposure, and their interactions, acute HSS males or females were significantly different than chronic TN males in BW, PCO₂, PO₂, sO₂, and Na⁺. Chronic HS males and females did not have significantly different blood electrolytes, acid-base regulation, and oxygen transport than chronic HSS males and females. Thus, selection for low FCR in heat stress at 31.1°C did not incur a fitness advantage when considering these parameters. Sexually mature males had significantly higher levels of hematocrit and hemoglobin than sexually immature quail and sexually mature females. Future studies using higher temperatures (32–34°C) could inform producers when to expect significant physiological changes in quail, lending to adaptions of feeding regiments according to environmental temperature and age.

1. FCR dataset
   1. Body weight of birds was taken when sexual dimorphisms were apparent and birds were singularly caged. Approximately half were male and half were female. 
   2. Feeders were placed outside of the cages with lids to prevent feed spillage. 
   3. Feed intake was taken daily at the same time in the morning before quails began eating to obtain the 24-hour feed intake. 
   4. After 7 days, body weight of birds was taken again.
2. Performance dataset
   1. Non-sibling male and female pairs were placed in the same cage to mate. 
   2. Eggs were collected and marked with the maternal wingband number from each pair every morning before the temperature increased in the temperature-controlled chambers which housed the birds.
   3. Eggs were collected for 2 weeks.
   4. Collected eggs were placed in a 12.78˚C chamber until all eggs were incubated together.
   5. At days 9, 11, 13, and 15 of incubation, 20 eggs were cracked open for tissue collection; however, abnormalities in development such as early embryo death, late embryo death, deformation/twins, and cracked eggs were noted. 
   6. Percentages of each abnormality were calculated. 
3. iSTAT dataset
   1. Singularly caged birds were handled no more than 2 times. 
   2. Birds were fasted for approximately 1 hour and weighed before blood draw from the jugular vein.
   3. Fresh, whole blood (100µL) was applied to the iSTAT CG8+ cartridge immediately after drawing to detect electrolytes, blood gases, glucose, hematocrit, and hemoglobin. 
   4. The cartridge was analyzed using the VetScan iSTAT-1 handheld blood analyzer. 

Microsoft Excel

RStudio

Numbers