The reproductive physiology in camelid species has its particularities. The present study aimed to characterize the ovarian follicular dynamics and its functional significance in relation to follicular deviation, vaginal cytological characteristics, and sexual hormone profiles in llamas as the first report in South American camelids. Non-pregnant, multiparous llamas (Lama glama; n = 10; age: 48–72 mo.; BCS: 2.5–3.0) were enrolled in the study. The ultrasonographic assessment was carried out transvaginally and follicular ablation was performed (day 0) when follicles were larger than 7 mm. The follicle number and diameter were scored daily throughout the process for a proper evaluation of the deviated follicles and to monitor the presence of new follicle pools (1.5 to 2.5 mm diameter). Vaginal cytological evaluation (parabasal, intermediate, and superficial cells) was performed every other day until day 6. Endocrine profiles (17β estradiol, anti-Mullerian hormone, testosterone, and progesterone) during pre- and post-follicular deviation were determined by using the ELISA assay. Differential follicular dynamics both in the presence of a single dominant follicle (DF) and in codominance during the follicular deviation process were detected in llamas (p < 0.05). The percentage of superficial cells was the most related to the follicular wave phase. However, the percentage of parabasal, intermediate, and superficial cells was not related to the phases of follicular growth, dominance, and regression (p > 0.05). Differential patterns among the different hormone concentration levels regarding the 17β estradiol, anti-Mullerian hormone, progesterone, and testosterone during follicular deviation were observed, with the latter being significantly different along the deviation process (p < 0.05). In conclusion, the use of vaginal cytology assessment would not be sufficient to determine the follicular phases in llamas. Therefore, complementary analyses, such as ultrasonography and endocrine assessment, are strongly recommended to determine follicular dynamics during the follicular deviation.

El objetivo del presente estudio fue determinar la sobrevivencia in vitro y la fertilidad in vivo de espermatozoides recuperados de la cola del epidídimo de toros criollos post mortem. Se colectaron 18 pares de testículos de toros criollos adultos del camal Municipal El Collao-Ilave, posterior a su sacrificio. Cada par de testículos fueron transportados al laboratorio y almacenados aleatoriamente en refrigeración a 5°C durante 0(n=6), 12(n=6) y 24(n=6) h. Al final de cada periodo, los espermatozoides fueron colectados y evaluados antes de la congelación y después de la descongelación en motilidad total, motilidad progresiva, test hiposmótico e integridad de acrosoma, congelados con dilutor Tris-yema de huevo (10%)-glicerol (7%) en pajillas de 0,25 mL con 30x106 espermatozoides motiles/pajilla. La prueba de fertilidad in vivo se realizó en 13 vacas, evidenciando que las características espermáticas evaluadas se preservaron antes de la congelación, pero a la descongelación fueron afectados por efecto de la refrigeración. Producto del proceso de la congelación y los espermatozoides congelados-descongelados, tuvieron capacidad de fertilizar. Por tanto, los espermatozoides colectados son congelables y pueden aplicarse en técnicas reproductivas asistidas.

The objective of this research was to evaluate the use of the intravaginal device (CIDR) and estradiol cypionate in synchronization protocols, on oestrus presentation, pregnancy and birth rate in Creole sheep under high altitude conditions. The study was carried out in a non-reproductive season, in the peruvian highlands, using 57 ewes. Four experimental groups were formed: group T1 (n=14) and T3 (n=14), CIDR progesterone device for 7 days and 12 days, respectively; group T2 (n=15) and T4 (n=14), CIDR progesterone device for 7 days and 12 days plus 1 mg of estradiol cypionate, 24 hours after removal of the device in both groups, respectively. Estrous presentation was observed from CIDR removal to 48 hours using vasectomized rams and IATF was performed with fresh semen 48 hours after device removal. The pregnancy rate was determined by ultrasonography at 46 and 90 days after FTAI and the birth rate was recorded. The chi-square test was used for statistical analysis. There was no difference (P>0.05) between groups, for estrous presentation, but there was difference (P<0.05) for pregnancy rate at 46 days between groups with: T1 (42.9%), T3 (38.5%), T4 (21.4%), with respect to T2 (0%) (The difference in results are shown in Table 2). There was a difference (P<0.05) for the pregnancy rate at 90 days: T1 (35.7%) and T3 (30.8%), with respect to T4 (7.1%) and T2 (0 %). The birth rate showed differences (P<0.05) for T1 (28.6%) and T3 (28.6%), with respect to T2 (0%) and T4 (0%). In conclusion, a high pregnancy rate was obtained with CIDR for 7 and 12 days, compared to the use of CIDR plus estradiol cypionate. However, no births were obtained with progesterone plus estradiol cypionate treatment.