Superovulación con pmsg aplicada en fase folicular fase luteal en alpacas

Superovulatory response after PMSG and LH hormones administration during follicular phase and induced luteal phase was evaluated in alpacas. The experiment was carried out during March and April, 1996, at la Raya, !VITA Camelids Research Station, located at 4 200 m. above sea level, 15° south, and 71° west. For this, fifteen empty females alpacas of the Huacaya breed, ranging from 2 to 11 years of age were divided in 3 equal groups (n = 5) and assigned to the following treatments: T1 (control): day O, 2 ml destilled water, i.m. injection; T₂ (follicular phase): day O, 1000 IU PMSG, i.m.; day 6, 1000 IU hCG, i.m.; and T₃ (induced luteal phase): day-7, progesterone application (vaginal pessaries); day O, 1000 IU PMSG, i.m.; day 2, remove progesterone pessaries; day 6, 1000 IU hCG, i.m. The ovarian response to the superovulation stimulation was ascertained by recording the number of corpora lutea (CL) through laparotomy and by measuring progesterone levels in blood circulation by RIA. The number and size of corpora lutea were significantly higher (P<0,05) in T₃ vs T₂ (17,80±8,34 vs 8,20±2,34 CL, and 13,64±2,00 vs 10,48±0,78 mm, respectively). As regards the blood progesterone levels (nmol/l), the results on day O were basal (T₁= 0,96±0,76; T₂= 1,17±1,03 and T₃= 3,51±0,97). However on day 16 these levels in T₂ (44,27±30,17) and T₃ (46,98±22,91) increased drastically but in T1, remained low (1,09±0,39). The correlation between CL formed and blood progesterone levels measured on day 16, was very low (r=-0,078; P<). We conclude that PMSG followed by hCG represent a good altemative for inducing superovulation in alpacas. However, from our results it would be advisable to investigate the effects of such hormones in lower dosis upon superovulation.