Recent studies document the LH-releasing pathway of nerve growth factor (NGF) in male camelids and that the LH response to seminal NGF is associated with elevated plasma testosterone concentration. Results provide rationale for the hypothesis that NGF in semen is associated with male fertility. In Experiment 1, the association between the amount of NGF in the ejaculate and characteristics of the male reproductive system was examined in alpacas. The concentration of NGF was measured by radioimmunoassay in semen samples collected from male alpacas (n = 47) and correlated with sperm morphology and motility, and measurements of the male reproductive anatomy. Most ejaculates had NGF concentrations that, based on previous studies, triggered ovulation in female camelids, however, we only found a positive correlation between NGF concentration with sperm concentration, thread formation and to...

Background: Alpacas have reproductive traits such as induced ovulation and a higher gestation rate in the left uterine horn (LUH). Additionally, low fertility and high embryonic mortality are significant challenges in alpaca breeding. To address these issues, it is essential to study the histological changes occurring in the uterine wall during day 8 of the luteal phase (LP). Aim: This research aims to describe these changes in alpacas with induced ovulation using GnRH or copulation. Methods: The study was conducted on 8 sexually mature fertile alpacas with a preovulatory follicle of ≥ 7 mm. Ovulation was induced with GnRH (G1, n = 3) and natural mating' (G2, n = 5), confirmed by ultrasound showing the disappearance of the follicle and formation of the corpus luteum (CL). On day 8 of the LP, samples of the uterine wall from the right and LUHs were obtained through a midline laparotomy....