200 Evaluation of Superovulatory Regimes for in Vivo Embryo Production in Alpacas (Lama Pacos)

Abstract

The objective of the study was to evaluate 4 superovulatory regimes in terms of the quantity of transferable embryos recovered. A total of 48 female alpacas, 3 to 5 years of age and located at Malkini Alpacas Farm (4100 m elevation), were distributed into 4 treatments. In treatment 1, 13 female alpacas received on Day 0 an intravaginal device containing 0.78 mg of progesterone (Cue Mate®, Bioniche Animal Health, Belleville, Ontario, Canada) followed immediately by an i.m injection of estradiol (1 mg of estradiol benzoate) and an i.m. injection of PGF2α (Veyx®, 0.25 mg of cloprostenol). The intravaginal device was removed on Day 7, performing at removal time an i.m. injection of estradiol. From Days 8 to 16, the alpacas received an i.m injection twice per day and 12 hours apart of pFSH (FolltropinV®, Bioniche Animal Health) in decreasing doses totaling 420 mg of pFSH; on Day 16,300 IU of eCGi.m. (Pregnecol®, Bioniche Animal Health) was injected. In treatment 2, 13 alpacas received on Day 0 an intravaginal device of progesterone followed by an i.m. injection of PGF2; from Days 5 to 9, alpacas received injections twice per day of decreasing doses of pFSH (porcine FHS) totaling 320 mg; on Day 7, the intravaginal device was removed and 500 IU i.m. of eCG was injected. In treatment 3,13 alpacas received on Day 0 an intravaginal device of progesterone followed immediately by an i.m injection of GnRH (Conceptal®, 0.0042 mg of acetate of busereline); pFSH was injected i.m. from Days 5 to 9 in decreasing doses twice per day, totaling 440 mg; the intravaginal device was removed on Day 7. In treatment 4, 9 female alpacas received on Day 0 an i.m. injection of GnRH after verifying the presence of a preovulatory follicle (>8.0 mm diameter). On Day 2, the alpacas received 1000 IU i.m. of eCG followed on Day 7 by an i.m. injection of PGF2. In all cases, the donor alpacas were evaluated by ultrasonography. The matings for treatments 1, 2, and 3 were performed twice per donor alpaca at 12-hour intervals between Days 5 and 8 of the initiation of the pFSH treatments, whereas in treatment 4 the matings were made the following day after the application of the PGF2. In treatment 1, the donor alpacas received at time of first mating an i.m injection of 3.75 mg of LH (Lutropin®, Bioniche Animal Health); in treatments 2, 3, and 4, the donors received an i.m. injection of GnRH. In all treatments, embryo collection was performed by nonsurgical method 6.5 days after first mating. There were significant differences between treatments (P < 0.05) in the mean number of CL, with treatment 4 being the highest (4.7 ± 2.63, 4.1 ± 3.05, 1.8 ± 1.8, and 6.0 ± 3.16 for treatments 1 to 4, respectively). The total number of blastocysts recovered per treatment was 7, 16, 2, and 18 for treatments 1 to 4, respectively. The superovulatory strategy followed for treatment 4 showed to be the one resulting in the highest number of transferable embryos. Further comparative evaluations between FSH and eCG treatments are recommended. Research was partially funded by the contributions of Bioniche Animal Health.

Aplicación De Tecnologías Reproductivas en El Perú, Su Impacto en El Desarrollo Ganadero, Retos Por Enfrentar

“…En los camélidos sudamericanos además de las ventajas de la TE comunes a todas las especies , se tiene la ventaja adicional de que la tecnología de transferencia embrionaria permite la reproducción de animales puros de una especie gestados en otra especie (transferencia ínter especies) lo cual podría permitir el rescate y multiplicación de especies silvestres como vicuñas y guanacos gestados en llamas o alpacas; así Taylor et al (2001) transfiriendo embriones de alpacas puras a llamas produjo crías alpaca normales que fueron aceptadas por las nodrizas y el rebaño de llamas al cual pertenecieron las recipientes; ese experimento fue también validado por nosotros (Vivanco et al, 2014) así como otros grupos de investigadores en el Perú (Huanca et al, 2012;Pacheco el at., 2016). En los primeros ensayos de superovulación en alpacas (Novoa y Sumar, 1968;Correa et al, 1992Correa et al, , 1994Novoa et al, 1999) se usaron diversas estrategias superovulatorias con resultados muy variables en términos del número de embriones transferibles por donante sometida a tratamiento superovulatorio, sin lograr que esta tecnología sea aplicable comercialmente pero después de varios años de trabajo en el desarrollo de regímenes superovulatorios, métodos de colección y transferencia embrionaria, tenemos hoy en día una tecnología repetible y comercialmente eficiente para la producción y transferencia embrionaria in vivo en alpacas (Vivanco et al 2014;2015c, Vivanco et al, 2009Vivanco, 2013;Vivanco-Mackie et al, 2015b) con un promedio de 4 embriones transferibles por alpaca por ronda de superovulación y 40% de nacimientos para embriones frescos. Nuestros trabajos de congelamiento y vitrificación de embriones si bien nos producen embriones con parámetros satisfactorios de desarrollo y gestaciones, éstas, sin embargo, se pierden alrededor del día 110 de gestación (Vivanco-Mackie et al, 2015b) por lo que aún seguimos trabajando intensamente para lograr este objetivo.…”