Comparison of superstimulatory protocols with different doses of eCG on ovarian response and oocyte recovery by follicular aspiration in llamas (Lama glama)

Abstract

The objective of this study was to evaluate the effect of three doses of equine chorionic gonadotropin (eCG) for ovarian superstimulation on ovarian response, follicular development and cumulus-oocyte complexes (COCs) collection in llamas. For this purpose, eighteen multiparous non-lactating adult (4–7 yo) female llamas with an average body condition of 2.8 (BCS 1–5) were submitted to a follicular ablation (FA) to induce a new follicular wave emergence. Two days after FA (Day 0), synchronized llamas were randomly allocated to three treatment groups (n = 6/group) and given 500, 750 and 1000 IU of eCG (Novormon®, Syntex, Buenos Aires, Argentina) per animal respectively to induce ovarian superstimulation. Transrectal ultrasonography were performed on Days 2, 4, and 6; and ovum pick up (OPU) was performed on Day 6. Data was evaluated by one-way analysis of variance (ANOVA), repeated measures ANOVA, and 2-tailed Chi-square. The average size (mm) of follicles was greater (p≤ 0.05) in the 1000 IU group compared to the other groups. There was a greater (p≤ 0.05) number of follicles ≥ 7 mm in the 1000 IU group compared to the 500 IU group. Number of COCs collected on Day 6 and the COC recovery rate were not different among groups. In conclusion, a single dose of 1000 IU of eCG induced the best ovarian response resulting in larger and greater number of follicles at the time of OPU.

Effect of Three Semen Extenders on Sperm Quality and In Vitro Fertilization Rates of Fresh and Cryopreserved Sperm Collected from Llama (Lama glama) Vas Deferens

“…Currently, these types of technologies are being used by different researchers in order to develop more successful protocols, although most of the trials carried out have been considered experimental in order to generate a suitable protocol for application in different South American camelid species [26]. Recently, our research team has obtained morula and blastocyst percentages that vary between 17.4% and 16.5%, respectively, at high altitude environmental conditions, using oocytes obtained from ovaries collected in slaughterhouses, which have been recovered using follicular aspiration techniques similar to those used in cattle [27,28].…”