Influência da somatotropina recombinante bovina (rbST) aplicada em receptoras de embriões bovinos, no dia do estro, sobre variáveis reprodutivas

• Ano de defesa: 2006
• Autor(a) principal: Marques, Paulo Alexandre Fernandes
• Orientador(a): Costa, Eduardo Paulino da
• Banca de defesa: Carvalho, Giovanni Ribeiro de , Mâncio, Antonio Bento
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Medicina Veterinária
• Departamento: Biotecnologia, diagnóstico e controle de doenças; Epidemiologia e controle de qualidade de prod. de
• País: BR
• Palavras-chave em Português: Somatotropina bovina; Taxa de gestação; Progesterona
• Palavras-chave em Inglês: Bovine somatotropin; Pregnancy rate; Progesterone
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/5118

The objective of the present study was to evaluate the effect of the administration, of 500 mg rbST (recombinant bovine somatotropin) in the moment of estrous of recipient heifers and cows inovulation with fresh embryos and 250 and 500 mg rbST in recipient inovulated with defrosted embryos, in progesterone serum concentration (P4) on the day of the inovulation and at the pregnancy rate at day 30. Blood samples were collected in the day of the inovulation by puncture of the coccygeal vein or artery for assaying of the serum P4 concentration. 259 crossbred recipients, appraised as able for reproduction, were used and divided in two studies. In the first study 144 recipient heifers received fresh embryos, randomly sorted among the experiments. The control (T1) was composed by 77 recipients, and the treated (T2) 67 recipients that received 500mg rbST at the moment of estrous. In a second study, it was used 115 recipients that receive defrosted embryos subdivided in 3 treatments. 53 recipient heifers composed the control (T1), the treated 2 (T2) was composed by 22 recipients that received 250 mg of rbST and the treated 3 (T3) was composed by 40 recipients that received 500 mg of rbST. The pregnancy rate of the first study was 65.7% (44 pregnant recipients) among the animals of T2 and 32.5% (25 pregnant recipients) at T1, which demonstrates the positive effect (P<0.01) from the use of rbST on pregnancy rate. However, the average concentrations of serum P4 in the day of the inovulation was 2.54±0.19 mg/ml for the animals of T1 and 2.27±0.20 mg/ml for the T2, there was no difference (P>0.05). The pregnancy rate of the second study recipients was 45.3% (24 recipients) among the animals of the group T1, 50.0% (11 recipient) for T2 and 52.5% (21 recipient) for T3. The average concentrations of serum P4 in the day of the inovulation were: T1 (control) = 5.41±2.33 mg/ml, T2 (250 mg rbST) = 5.77±2.19 mg/ml and T3 (treated - 500 mg rbST) = 4.77 ± 1.78 mg/ml. The results of the second study demonstrate the absence of effect (P>0.05) on the rbST use over the pregnancy rate and the serum P4 concentration. We can conclude that the administration of 500 mg rbST in recipient inovulation that receive fresh embryo at the moment of the estrous was able to improve the pregnancy rate, but not the concentration of progesterone serum P4. However, when administered 250 or 500 mg rbST in recipient inovulated that receive defrosted embryos, we are able to conclude that there was no positive effect on the pregnancy rate and on the progesterone serum concentration.