Table 1. Use of cortisol as a biomarker in previous studies of stress in animals.

Stress type	Species	Biomatrices
Acute	Cow	Blood [14], saliva [14,15], urine [16], milk [17], feces [18]
	Sheep	Blood [19], saliva [19], urine [20], feces [19]
	Pig	Blood [21], saliva [22,23], urine [24], feces [25]
	Fish	Blood [26], respiratory vapor [27]
Chronic	Cow	Hair [28], hooves and claws [29]
	Sheep	Wool [30]
	Pig	Hair [31]
	Fish	Scales [32], fins [33]