Abstract

YOSTAR, EJ; MUJICA, IF; STAHRINGER, RC  and  CAPELLARI, A. Comparison of twoprotocols for superovulation in Braford embryo donors. Rev. vet. [online]. 2021, vol.32, n.2, pp.146-150. ISSN 1669-6840.  http://dx.doi.org/10.30972/vet.3225721.

Embryo transfer is the process of collecting embryos from a given female (donor) and transferring them to other (receptors) to continue gestation. The superovulatory treatments are characterized by induce very variable responses, so it is impossible to estimate the number of embryos recovered by donor. Because the problems related to the great variability of super ovulatory treatments we performed here a preliminary assay including super stimulation on day 3 after synchronizing the new follicular wave. The objective of this study was to evaluate the super ovulatory response to two super stimulation protocols in donors from the Argentine north-east region (NEA). We worked with 60 Braford donors from 5 cow breeders, randomly assigned to two treatments (T1: n=30 and T2: n=30), in each collections program, 12 donors were utilized. In T1, super ovulation started on day 3 (considering day 0 at the time of placement of progesterone device and 17 p estradiol) thus shortening the entire treatment and concluding with collection of the embryos on day 14 and not 15 as in T2. The analyzed variables were: total structures subdivided into: transferable embryos, degenerate embryos and unfertilized oocytes. The number of transferable embryos achieved was 7±1.19 and 6±0.89, degenerate embryos of 1±0.32 and 1±0.24 and unfertilized oocytes of 3±0.86 and 7±1.83 in T1 and T2, respectively. The independence test showed statistically significant evidence to declare the association between treatments and structures recovered in the collection with a frequency of 62% for transferable embryos in T1 and 44% in T2 (p<0.0001). We conclude that although the anticipated use of FSH in ST did not allow to improve super ovulatory response it can be used strategically without affecting the production of embryos.

Keywords : bovines; embryo transfer; ultrasonography; hormone FSH.

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