100 Use of Seminal Plasma, Human Chorionic Gonadotropin, and Follicular Ablation on the Interval to Follicular Wave Emergency and Dominant Follicle in Alpacas (Vicugna pacos)
Alpacas, as other camelids, are inducer ovulators and FIO/NGF-β, a protein present in the seminal plasma (SP) is reported as the responsible of the ovulation (Kershaw-Young et al. 2012 Reprod. Fertil. Dev. 24, 1093-1097, 10.1071/RD12039). However, limited and controversial information exists regarding characteristics of follicular wave in alpacas post-induction of ovulation with SP or other stimulus. The experiment was designed to determine the effect of 3 external stimulations on the interval to follicular wave emergence and the interval to dominant follicle. Adult female alpacas between 5 and 6 years old were assigned to 1 of 3 treatments: (1) SP (n = 6): 1 mL of SP IM; (2) hCG (n = 5): 1000 IU of hCG (Pregnyl, Organon-Holland, Amsterdam, the Netherlands), via IM; or (3) follicular ablation (FA, n = 6): animals were induced by ultrasound-guided ablation of the dominant follicle ≥7 mm. Alpacas from treatments 1 and 2 were examined by ultrasonography (Aloka SSD 500, transducer 7.5 MHz; Aloka, Tokyo, Japan) at 1- to 2-h intervals between 22 and 30 h after treatment or until ovulation occurred, whichever occurred first. All animals were evaluated by ultrasonography every day from Day 2 to Day 7 post-treatment and after that on Days 9, 12, and 15 post-treatment. Data from one alpaca (FA group) was excluded because of problems in the timing of ablation. Therefore, the total number of alpaca used was 16 (SP = 6, hCG = 5, and FA = 5). Results of the effect in external stimulation were analysed using ANOVA. In conclusion, interval to the emergence of a new follicular wave on the detection of follicles ≥3 mm and interval to dominant follicle ≥7 mm differed for FA compared with hCG but not compared with SP treatment. Table 1.Follicular wave emergence (mean ± SEM) under 3 external stimulations: seminal plasma (SP), hCG, or follicular ablation (FA)