Oxidative response of sheep to transcervical applications.

This study aimed to investigate the stress-related changes that may occur in sheep following non-surgical cervical line passage. A total of 20 sheep underwent transcervical transition, and their heart rate, respiratory rate, body temperature, and blood samples were collected at specific time points: 1 h prior to the procedure, immediately after the procedure, and at 1, 2, 3, 4 and 5 h post-procedure. The study found that there was a statistically significant decrease in body temperature immediately after the procedure (p < .05); however, there were no significant differences in body temperature at other time points (p > .05). Respiratory rate remained similar throughout the study, and no significant differences were observed (p > .05). On the other hand, there was a significant increase in heart rate at the 1-h mark after the procedure (p < .05), which subsequently decreased to a similar level as the control group at the 4-h mark after the procedure (p > .05). The cortisol levels increased significantly after the application (p < .05) but decreased to a level similar to the control after 1 h (p > .05). The level of nitric oxide increased significantly in the first hour (p < .05) and decreased by the 5th hour (p < .05). There was a significant increase in malondialdehyde (MDA) and total oxidant capacity (TOC) levels 2 h after the application (p < .05), but this increase ceased at the 4th and 5th hours for MDA (p > .05) and at the 3rd, 4th and 5th hours for TOC (p > .05). The total antioxidant capacity decreased after the 2nd hour of application (p < .05) but remained similar at the fourth and 5th hours (p > .05). In conclusion, based on the cortisol data, transcervical manipulations create short-term stress. Therefore, it may be necessary to use various antioxidants before such procedures to reduce the effects of oxidative stress.

Effects of alpha-lipoic acid on ram semen cryopreservation and post-thaw life span.

The aim of the present study was to evaluate the effects of an alpha-lipoic acid-supplemented extender on ram semen at a post-thaw stage and after incubation (6 hr). Semen samples were collected from five Kivircik Rams. Pooled semen was diluted with an egg yolk-based extender with different concentrations of alpha-lipoic acid (0.25 mmol L-1 , 0.5 mmol L-1 and 1 mmol L-1 ) and without alpha-lipoic acid. Motility, plasma membrane functional integrity (HOST), acrosome integrity (FITC-Pisum sativum agglutinin) and DNA integrity (TUNEL) were assessed at post-thaw and 6 hr after incubation of the frozen-thawed semen. At the post-thaw stage, 0.25 mmol L-1 alpha-lipoic acid had a positive effect on sperm motility and plasma membrane functional integrity compared to the control group (p < .05). At the post-incubation stage (6 hr), it was determined that the motility and plasma membrane functional integrity of the antioxidant groups were adversely affected compared to the control group (p < .05) and 1 mmol L-1 dose of alpha-lipoic acid had a harmful effect on DNA integrity compared to the control group (p < .05). The results of the study demonstrated that alpha-lipoic acid has positive effects at post-thaw but have harmful effects on long term to ram semen.