Table 1.

Sampling.

Chicken Breed	Feeding location	Sample size	Altitude/m	Longitude	Latitude	Oxygen partial pressure (mmHg)
Snowy white chicken	Lhasa, Tibet	24	3650	91°01′	29°26′	115.8
	Ya'an, Sichuan	24	600	102°38′	29°43′	151.8