Semen from alpacas was collected by two methods: by aspiration from the female’s vagina following mating and with an artificial vagina. Semen was collected, evaluated and extended with Tris buffer, and then used in artificial insemination. Altogether 160 female alpacas with proven reproductive history and five males were used. Semen was collected by vaginal aspiration from 10 females using five males as semen donors; likewise, semen from the same males was collected with an artificial vagina twice a week 50 times. Volume, motility, spermatic concentration, live spermatozoa, viscosity and color was evaluated. Seminal characteristics of semen collected by aspiration and with an artificial vagina were: volume (3.6 and 1.5 mL), motility (73.4 and 69.0%), sperm concentration (75.2 and 80.3 million/mL), live spermatozoa (75.3 and 70.8%) respectively, with statistical difference between metho...

Semen de alpaca fue colectado por dos métodos: por aspiración de la vagina de la hembra después de la monta natural y con vagina artificial. El semen colectado fue evaluado y diluido con Tris tamponado, y luego usado en inseminacion artificial. Se trabajó con 160 alpacas hembras adultas de capacidad reproductiva comprobada y 5 alpacas machos. Se colectó semen post cópula de los cinco machos en 10 hembras, y se hicieron 50 colecciones de semen con vagina artificial de estos machos, dos veces por semana. Se determinó volumen, motilidad, concentración espermática, porcentaje de espermatozoides vivos, viscosidad y color. Los resultados para semen colectado por aspiración de la vagina y con vaginal artificial fueron: volumen (3.6 y 1.5 mL), motilidad (73.4 y 69.0%), concentración espermática (75.2 y 80.3 millones/mL), espermatozoides vivos (75.3 y 70.8%), respectivamente, con dife...

The aim of this study was to evaluate the pregnancy and natality rate of artificial insemination (AI) in alpacas, using fresh semen, with one and two services, in Cusco, Peru. Semen from 10 alpacas was collected by the post-copula method between January and March, using ejaculates that had volume ≥1 ml, motility ≥60% and light red or creamy white color. The ejaculates were diluted in Tris-glucose and egg yolk at a concentration of 20%. For AI, alpacas with history of previous births, ≥20-day post-partum and body condition ≥3, receptive to the male and with a preovulatory follicle ≥7 mm were selected. The induction of ovulation was done with the administration of 80 μg buserelin/animal. The females were inseminated 26-30 h after the induction of ovulation, with diluted fresh semen (1 ml with 25x106 spermatozoa), deposited inside the body of the uterus. The diagnosis of pregnanc...

The aim of this study was to evaluate the pregnancy and natality rate of artificial insemination (AI) in alpacas, using fresh semen, with one and two services, in Cusco, Peru. Semen from 10 alpacas was collected by the post-copula method between January and March, using ejaculates that had volume ≥1 ml, motility ≥60% and light red or creamy white color. The ejaculates were diluted in Tris-glucose and egg yolk at a concentration of 20%. For AI, alpacas with history of previous births, ≥20-day post-partum and body condition ≥3, receptive to the male and with a preovulatory follicle ≥7 mm were selected. The induction of ovulation was done with the administration of 80 μg buserelin/animal. The females were inseminated 26-30 h after the induction of ovulation, with diluted fresh semen (1 ml with 25x106 spermatozoa), deposited inside the body of the uterus. The diagnosis of pregnanc...

The aim of this study was to evaluate the effect of fresh (YHF) and powder (YHP) egg yolk on the motility, viability, functional integrity of the plasma membrane (HOST) and pregnancy rate after insemination using fresh and chilled semen. Thirty ejaculates of five alpacas were collected by the post-copulation method during the months of January to March. Ejaculates were diluted in Tris-glucose plus glycerol to a final concentration of 5%, and the two types of egg yolk were added at a final concentration of 20%. Diluted semen was separated into aliquots and maintained at 15 °C for 8 h and 5 °C for 24 h, where 180 alpacas were inseminated. Motility, viability and sperm HOST value stored at 15 and 5 °C were not affected by the type of egg yolk. Similarly, pregnancy rates were rather similar when inseminated with fresh semen (50.0 and 46.7%), or kept at 15 °C (43.3 and 40%) or 5 °C (33.3...

El objetivo del estudio fue evaluar el efecto de la yema de huevo fresca (YHF) y en polvo (YHP) sobre la motilidad, viabilidad, integridad funcional de la membrana plasmática (HOST) y tasa de preñez con semen fresco y refrigerado. Se colectaron 30 eyaculados de cinco alpacas mediante el método poscópula en los meses de enero a marzo. Los eyaculados fueron diluidos en Tris-glucosa y glicerol a una concentración final de 5%, y usando los dos tipos de yema de huevo a una concentración final de 20%. El semen diluido se separó en alícuotas y se mantuvo a 15 ºC por 8 h y a 5 ºC por 24 h, y se inseminaron 180 alpacas. El tipo de yema no afectó la motilidad,  viabilidad y el valor HOST en los espermatozoides conservados a 15 y 5 ºC. De igual manera, los porcentajes de preñez no variaron cuando se inseminaron con semen fresco (50.0 y 46.7%), mantenido a 15 ºC (43.3 y 40%) o refrige...

The effect of testosterone on penis-prepucial adherences and production of fibre was studied in 30 alpacas. Animals were 18 months old and were distributed in three groups: without treatment (T0), treated with testosterone enanthate (0.5 mg/kg/body weight) every two weeks during 12 weeks (T2E), and castrated (C0). The penis-prepucial adherences, testicular size, sexual behavior and body weight were evaluated every two weeks, and fibre samples were collected at the beginning of the study and at the end of three experimental periods. In a 4-week pre-experimental phase all parameters were evaluated for adjusting the data of the experimental phase. Release of penis-prepucial adherences was greater in T2E than in T0 and C0 between weeks 8 (p<0.001) and week 12 (0.006>p<0.001). Higher testicular size (length, width, and thickness) occurred in T0 than in T2E between weeks 4 and 12 (0.0...

Se evaluó el efecto de la testosterona sobre las adherencias pene-prepuciales y producción de fibra. Se usaron 30 alpacas de 18 meses de edad, distribuidas al azar en tres grupos: machos sin tratamiento (T0), machos tratados con enantato de testosterona (0.5 mg/kg/peso vivo) cada dos semanas durante 12 semanas (T2E), y machos castrados (C0). Las adherencias pene-prepuciales, tamaño testicular, comportamiento sexual y peso corporal se evaluaron cada dos semanas, y muestras de fibra se recolectaron al inicio delestudio y al final de tres periodos experimentales. Se tuvo una fase pre-experimental de cuatro semanas donde se evaluaron los parámetros en estudio para ajustar los datos de la fase experimental. La liberación de las adherencias pene-prepuciales fue mayor en T2E que en T0 y C0 entre la semana 8 (p<0.001) y la semana 12 (0.006>p<0.001). El incremento testicular (largo,...