132 Different protocols using progesterone and long-acting meloxicam in an equine embryo transference program
I. B. Domingues A , V. L. T. Jesus A , P. J. Ferraz A , I. P. F. Santos A , B. Bringel B , R. H. Douglas B and J. C. F. Jacob AA Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brasil
B B.E.T. Laboratories, Lexington, KY, USA
Reproduction, Fertility and Development 35(2) 194-194 https://doi.org/10.1071/RDv35n2Ab132
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
In equine embryo transfer (ET), one of the most serious problems is embryo loss. The two main factors responding for such losses are corpus luteum insufficiency, with diminished production of progesterone, and cervical manipulation at the time of ET, which can lead to uterine inflammation, PGF2α release, luteolysis, and embryo loss. The purpose of this experiment was to study the effectiveness of treatment of recipient mares on the day of ET with a long-acting progesterone (P4 L.A.) ± long-acting meloxicam (L.A.). A total of 78 recipients were studied in two stud farms located in the region of Três Rios, Rio de Janeiro, Brazil. The recipients were divided in six groups: four cyclic groups (I to IV) and two acyclic groups (V and VI). Group I (control, n = 19); Group II (n = 22): 1.5 g of P4 L.A. (BioRelease Technologies LLC®); Group III (n = 17): 1.5 g of l P4 L.A. and 1.5 g of long-acting meloxicam (BioRelease Technologies LLC®); Group IV (n = 9): 1.5 g of meloxicam (L.A.). The groups of acyclic recipients were Group V (n = 6): 1.5 g of P4 L.A. and Group VI (n = 5): 1.5 g of P4 L.A. and 1.5 g of meloxicam (L.A.). Recipients received 5 mg oestradiol benzoate on the day the donor ovulated and 1.5 g of P4 L.A. 48 h later; the embryo was transferred four days later. The pregnancy diagnosis was issued seven days after ET and the confirmation of pregnancy on Day 45. Of the 78 embryos transferred, 53 pregnancies were detected at 15 days and 45 pregnancies were confirmed at 45 days. For embryo recovery, comparison was performed using the nonparametric Wilcoxon test; 5% significance was considered. The results for pregnancy rate on Day 15 were: Group I, 47.4% (9/19); Group II, 63.6% (14/22); Group III, 82.4% (14/17); Group IV, 77.8% (7/9); Group V, 100% (6/6); Group VI, 60% (3/5). On Day 45, pregnancy rates were as follows: Group I = 8 (42.1%); Group II = 13 (59.1%); Group III = 12 (70.6%); Group IV = 5 (55.6%); Group V = 4 (66.7%); Group VI = 3 (60%). The present study found a significant difference (P < 0.05) in pregnancy rate in Groups III and V compared with the other groups on the 15th day. Pregnancy rate also showed a significant difference on the 45th day in Group III compared with the other groups (P < 0.05). The use of acyclic recipients, prepared with a 5 mg of oestradiol benzoate and 1.5 g of long-acting P4, proved feasible for use in an ET program, with good results. Based on the present study, it could be concluded that the use of long-acting P4 associated with a long-acting anti-inflammatory at ET procedure improves pregnancy rates in recipient mares.
This research was supported by CAPES, Brasil, and B.E.T. Laboratories.
