Resumo

CHIPAYO G., Ysaac; LEYVA V., Víctor  e  GARCIA V., Wilber. Efecto del estradiol en el periodo de reconocimiento maternal de la preñez sobre la supervivencia embrionaria en alpacas. Rev. investig. vet. Perú [online]. 2003, vol.14, n.2, pp.111-118. ISSN 1609-9117.

The effect of oestradiol (E2) during the maternal recognition of pregnancy (9-11 days after ovulation) was studied in 44 alpacas that were 20 days after delivery. The alpacas were mated with an intact male (15 minutes) and received 500 IU of hCG to induce ovulation. The females were divided in 3 groups: The group G₁ (n=14) received 0.2 ml. Im of an A, D and E vitaminic complex days 8 and 9 post-ovulation. In the second group G₂ (n=15) each alpaca received 200 mg of E₂ and 0.2 ml im. of the vitamin complex on (similar to G₁) on days 8 and 9 post-ovulation. The group (G₃; n=15) received 20 mg of progesterone and 0.2 ml im of the some vitamin complex on day 9 post-ovulation. The females were confronted with a male to evaluate their sexual behavior (accept or denial) after then, transrectal ecography of the ovaries and uterus was conducted on days 2, 8, 13,19, 27, 30 and 60 post-ovulation. Embryonic survival was higher in G2 (86.7%) at day 19 in comparison to G1 (57.1% p<0.08), but without G₃ (73.33%). Follicular dinamics in alpacas with embryonic servival was different at day (p<0.01) but not on day 8 relating to those animal with embrionic mortality. In days 30 and 60 post ovulation the differences between G₁ (50%) and G2 (80%) were still present (p<0.1) and G3 (73.33)continue without differences to G1. The size of the corpus luteum did not have statistical differences between the three groups but was smaller in those with embryonic mortality at day 13 (10.7 ± 1.6 vs. 13.3 ± 1.5, p<0.05) which would show that the luteolisis process began at day 13 in that group. These results suggest that failure in maternal recognition of pregnancy and subsequent embryo mortality were reduced by the oestradiol, and there fave indicating that o estradiol plays an important rol in the process of maternal recognition of pregnancy in alpacas.

Palavras-chave : oestradiol; alpaca; maternal recognition; corpus luteum.

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