Características reprodutivas e taxa de gestação em éguas receptoras da raça Mangalarga Marchador tratadas com Gonadotrofina Coriônica Humana (hCG)

• Autor(a) principal: Lourenço, Gilberto Guimarães
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5824
• topic: Equino - Reprodução; Transferência de embriões; hCG; Equine - Reproduction; Embryo transfer; hCG; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL

The aim of the present study was to improve reproductive conditions of mares candidates as embryo recipient through hCG (human chorionic gonadotrophin) administration. Four days after ovulation (D4), recipient mares were divided in two groups: G1 control (n = 24) administration of 2 mL of physiologic solution (i.m) and G2 treatment (n = 26) administration of 2.000 IU of hCG (Chorulon®; i.m). Uterine and cervical tonus, uterine echotexture and edema, diameter of corpus luteum (CL), CL circumference and area, and diameter of the largest follicle in each ovary were evaluated in both groups on days 4, 8 and 13 (day 0 = ovulation) by transretal palpation and/or ultrassonography. Additionally, quality of transferred embryos and asynchrony between recipient and donor were also evaluated. Blood samples from recipient mares were collected on D0, D4, D8 and D13 for progesterone assay. Higher concentration of plasmatic progesterone (p < 0,05) was observed in G1 on D0 and D4 than in treated group (G2), although no significant difference was observed on D8 and D13 between groups. No difference (p > 0,05) were observed between groups for uterine and cervical tonus characteristics, uterine edema and echotexture, diameter, circumference and area of the corpus luteum. The degree of asynchrony between recipients and donors and the quality of embryos transferred to recipients did not differed (p > 0,05) between groups. The pregnancy rates were 84,6% (22/26) and 75% (18/24) for treated and control groups, respectively (p > 0,05). In conclusion, based on the conditions of the present study, treatment with hCG did not improve plasma progesterone concentration, pregnancy rate of recipient mares and did not change reproductive characteristics of recipient mares in diestrus.