Changes in mohair cortisol concentration and fiber growth during gestation in Angora goats

The hypothalamic–pituitary–adrenal (HPA) axis plays a central role in regulating long-term stress responses. Keratin-based matrices represent a noninvasive approach for assessing long-term HPA axis activity in farm animals. The present study investigates gestational changes in mohair cortisol concentration and mohair fiber length in Angora goats under routine farm conditions. Clinically healthy does (n = 29; 14 aged 1.5 years and 15 aged 2.5 years) were monitored during the breeding season, and pregnancy was confirmed in 16 does. Mohair samples were collected monthly, fiber length was measured, and cortisol concentrations were quantified using an ELISA. Mohair cortisol concentrations were not significantly affected by age group or pregnancy status (p > 0.05); however, significant month × age and month × pregnancy interactions were detected (p < 0.05). Mohair fiber length varied significantly across months (p < 0.05), and a significant month × pregnancy interaction was detected (p < 0.05), whereas age and month × age interactions had no significant effect (p > 0.05). No significant correlation was observed between fiber length and mohair cortisol concentration. Despite the limitations associated with repeated sample collections under field conditions, the findings suggest that mohair may serve as a practical and noninvasive matrix for evaluating chronic HPA axis activity in Angora goats.