Transfer of cooled llama embryos obtained from synchronized females

Abstract

This study evaluated the efficiency of a synchronization protocol based on GnRH and PGF_2α on embryo donor llamas for fixed timed mating and assessed the viability of embryos maintained at 5 °C and 15 °C for 24 h, using the Equitainer® and the Botu-BOX® as cooling devices respectively. Llamas were divided into four follicular wave groups: growth, dominance, static and regression; they received a GnRH analogue on day 0 followed by a second dose plus cloprostenol on day 8 and 15 and mating was indicated in females with a follicle ≥ 6 mm. Embryos were recovered 8 days post mating. Synchronization rate was 80% for the treated embryo donors, with no significant differences among groups. Uterine flushing was performed in 70% of the treated females (87.5% of mated llamas) and an embryo was recovered in 50%. Fourteen embryos were assigned randomly to 5 °C (Equitainer® group) and 15 °C (Botu-BOX® group) preservation for 24 h to be transferred later. In the Equitainer® group, we obtained 14% pregnancies and a female offspring was born. In the Botu-BOX® group, 28% resulted pregnant but subsequently pregnancies were lost. This protocol was effective for synchronizing follicles in growth phase in 80% of embryo donor llamas. In addition, cooling llama embryos using the Equitainer® and the Botu-BOX® as cooling devices to 5 °C and 15 °C respectively, preserves its morphology and viability for 24 h.