# Short communication: salivary cortisol concentrations and lying behavior of ewes in response to semi-laparoscopic and laparoscopic embryo transfer

## TL;DR

This study found that embryo transfer procedures in sheep did not cause significant stress, as measured by cortisol levels and lying behavior.

## Contribution

The study compares stress responses in ewes undergoing two embryo transfer methods and finds no significant differences in stress levels.

## Key findings

- Salivary cortisol concentrations increased temporarily but returned to baseline within 24 hours.
- Lying behavior patterns changed post-surgery but were not significantly different between groups.
- Both embryo transfer methods caused similar stress responses compared to handling alone.

## Abstract

This study compared the short-term effects of the laparoscopic and semi-laparoscopic embryo transfer (ET) procedures on salivary cortisol concentrations and the lying behavior of ewes. In total, 40 ewes were synchronized for ET and placed randomly into individual pens 2 d before the operations. On the day of the operations, laparoscopic (L, n = 15) and semi-laparoscopic (SL, n = 10) ET were performed. At the same time, control animals (Control, n = 15) were placed into the laparoscopic cradle for 6 min without an ET procedure. Monitoring of standing and lying behaviors started 24 h before the surgery and lasted until 24 h after the procedures were completed. Saliva samples were taken 4 times during the experiment and assayed for cortisol concentrations. Saliva cortisol concentrations were elevated in all groups 1 (Control: 4.8 ± 0.5 ng/mL; L: 5.1 ± 0.5 ng/mL; SL: 4.2 ± 0.7 ng/mL) and 2 (Control: 5.5 ± 0.5 ng/mL; L: 5.9 ± 0.5 ng/mL; SL: 4.8 ± 0.7 mg/mL) hours after the procedures compared to the initial concentration (Control: 3.8 ± 0.5 ng/mL; L: 3.7 ± 0.5 ng/mL; SL: 3.1 ± 0.7 ng/mL), and returned to the basal levels for the end of the 24-h post-surgery period (Control: 3.4 ± 0.5 ng/mL; L: 4.1 ± 0.5 ng/mL; SL: 3.5 ± 0.7 ng/mL). There were no significant differences in the cortisol levels among the groups. There was no difference in the total lying time between the groups 24 h before or after the surgery. The average length of lying bouts calculated for the 24-h post-surgery period increased in all groups from the 24-h pre-surgery period, with a parallel decrement in the number of lying bouts (P < 0.05). Our results suggest that the laparoscopic and semi-laparoscopic ET did not cause more stress in the ewes than the handling procedures related to surgery and preparation.

The laparoscopic and semi-laparoscopic embryo transfer procedures did not cause considerable stress to the ewes.