Pregnancy and birth rate outcomes in alpacas (Vicugna pacos) inseminated with frozen semen using two commercial extenders

Abstract

The aim of this study was to evaluate alpaca pregnancy outcomes and birth rates of females inseminated with frozen semen using two commercial extenders. A total of 18 ejaculates from 8 adult alpaca males were obtained with artificial vagina, and macroscopic and microscopic semen characteristics were assessed. Afterwards, samples were divided into two aliquots, diluted with Biladyl® B or AndroMed®, and cooled for 2 h at 5°C. At that moment, sperm motility was evaluated, and samples were frozen through a gradual descent of temperature using a liquid nitrogen tank. To analyse frozen sperm quality, samples were thawed at 38°C for 30 s. Even though a significant decrease in sperm motility and viability was detected when thawed (p <.05), no superiority was found between the two commercial extenders (Biladyl® B vs. AndroMed®). A total of 36 alpaca females were artificially inseminated (AI) between 30 and 34 h post-injection of a GnRH analogue, administered when a growing dominant follicle was detected through transrectal palpation and ultrasonography. Obtained pregnancy rates were similar between Biladyl® B (33.3%, 6/18) and AndroMed® (22.2%, 4/18). No significant differences were detected in birth rates between the two tested extenders, obtaining 4 and 3 births for Biladyl® and AndroMed®, respectively. In conclusion, alpaca pregnancies and alive offspring can be obtained through AI with frozen semen at similar efficiency rates using commercial diluents, Biladyl® B or AndroMed®.