Background: Castration is a husbandry practice raising important questions on the welfare and physiological status
of farm animals. Searching for effective castration methods that minimally compromise the body physiology is
worthy of attention. Therefore, this study aimed to evaluate the differential response of biological systems in
donkeys to surgical castration versus the chemical one by CaCl2 with special emphasis on stress, lipid profile, and
oxidative stress biomarkers. Donkeys were divided randomly and equally into two groups; the chemical (Ch) and
surgical (S) groups (n = 6). The Ch group was chemically castrated by intratesticular injection of 20% CaCl2 dissolved
in absolute ethanol. Blood samples were collected prior to castration and at 15, 30, 45, and 60 days after the
beginning of experiment.
Results: Surprisingly, the Ch group at the end of the experiment was characterized by significantly higher cortisol
level compared to the S group. TC and LDL-C levels in the S group significantly decreased at day 45, while TG
levels significantly increased at days 45 and 60 in comparison with day 0. HDL-C levels at days 30 and 60 in the Ch
group significantly increased in comparison with day 0. At day 30 post-castration, HDL-C was significantly higher
and LDL-C was significantly lower in the Ch group than the S group. A significant elevation in TC and LDL-C was
observed at day 45 and in HDL-C at the end of experimental duration in the Ch group when compared with the S
group. TPX level was significantly lower and TAC was significantly higher in the Ch group at day 45 than the S
group.
Conclusion: Surgical castration evoked less stress and minor changes in lipid profile and oxidant/antioxidant
balance relative to chemical castration by intratesticular 20% CaCl2 dissolved in absolute ethanol.
Keywords: Surgical castration, Chemical castration, Physiology, Stress, Lipid profile, Oxidative stress