Taxa de gestação e concentração sérica de progesterona em receptoras de embrião bovino tratadas com somatotropina recombinante bovina (rbST)

• Autor(a) principal: Haas, Giorgia Thaís da Silva
• Data de Publicação: 2004
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4988
• topic: Bovino; Reprodução; Inseminação artificial; Somatotropina bovina; Transferência de embriões; Bovine; Reproduction; Artificial insemination; Somatotropin; Embryo transfer; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL

The purpose of this work was to evaluate the effects of rbST on the gestation rate and in the endogenous progesterone concentrations in embryo recipient heifers. Fifty two recipients were selected randomly and allocated in two treatments: (i) The first (T1) - 22 heifers with no application of rbST (Control treatment); (ii) and the second one with 30 heifers, were treated with a single subcutaneous injection of 250 mg rbST (rbST treatment), applied at detected estrus. Heifers from both treatments received fresh embryos, on day six or eight from the detected estrus. At the same time, blood samples were collected from the coccygeal vein or artery so as to perform the progesterone analysis using the radioimmunoassay technique. Twenty eight days after detected estrus, heifers were ultrasonically scanned per rectum to determine the pregnancy rate. No significant difference (P>0.05) was observed in the pregnancy rate between control (50%) and rbST (46.6%) treated heifers, or in the progesterone concentration, with mean values of 1.71 ± 0.74 ng/mL, and by 1.48 ± 0.72 ng/mL for control and rbST treated animals, respectively. In conclusion, the application of 250 mg rbST, at detected estrus in heifers, was not effective to increases pregnancy rate and progesterone concentration.