Authors: Korzekwa Anna J, Kordan Władysław, Kotlarczyk Angelika M, Kozdrowski Roland
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Effective oestrous synchronisation in farmed deer requires reliable methods that maintain consistent progesterone and oestradiol profiles whilst minimising tissue trauma. This Polish study compared two intravaginal synchronisation protocols in 14 red hinds: CIDR inserts (0.3 g progesterone for two 12-day cycles) versus Chronogest sponges (20 mg flugestone acetate for two 7-day cycles), both followed by 200 IU eCG injection, with frozen-thawed semen delivered at 12 and 24 hours post-oestrus. Radioimmunoassay hormone analysis revealed that whilst both methods produced appropriate steroid profiles, the sponge-based protocol achieved superior results: five confirmed pregnancies and five live calves versus two pregnancies and one calf in the CIDR group, with improved hormone responsiveness across the cycle. The poorer performance of CIDR inserts appeared linked to incomplete vaginal retention in hinds, potentially triggering inflammatory responses that disrupted endocrine regulation. For practitioners managing deer breeding programmes, these findings suggest that flugestone acetate sponges offer more reliable synchronisation outcomes than progesterone-releasing devices, likely owing to better anatomical fit and reduced mucosal irritation in the cervid reproductive tract.
Read the full abstract on PubMed
Practical Takeaways
- •For deer farmers using estrous synchronization, chronogest sponges appear more effective than CIDR devices in hinds, with nearly 3x higher pregnancy rates and live calf production
- •Device retention and fit to species-specific anatomy is critical; CIDR inserts designed for cattle do not reliably stay positioned in red deer vaginas
- •The combination of chronogest sponge + eCG injection provides a practical protocol for timed artificial insemination in red deer breeding programs
Key Findings
- •Group II (chronogest sponge) achieved 5 pregnancies vs Group I (CIDR insert) with 2 pregnancies based on PAG concentration
- •Group II produced 5 live calves compared to 1 in Group I, indicating better overall fertility outcomes
- •Chronogest sponge resulted in better hormone responsiveness and pregnancy rates than CIDR inserts in hinds
- •CIDR inserts were incompletely retained in hind vaginal anatomy, potentially causing bacterial inflammation and endocrine disruption