Transferência de embriões como ferramenta para formação de rebanho experimental ovino e análise dos fatores que podem maximizar a multiplicação do plantel / Embryo transfer as a tool to experimental sheep flock formation and stock multiplication factors analyses

Visando ao aumento do plantel de ovinos da raça Black Belly na estação experimental do Institut Scientifique de Recherche Agronomique (INRA) de Bourges, França, foram utilizadas 32 ovelhas da raça Black Belly superovuladas com FSH suíno nos últimos três dias de tratamento progestágeno de 14 dias. Após coleta cirúrgica, obtiveram-se 264 embriões transferíveis (8,2 ± 6,0/doadoras), sendo transferidos 232 a 88 receptoras da raça Romane pluríparas e 23 da raça Suffolk nulíparas. As taxas de parição e de sobrevivência embrionária foram 83,6 e 63%, respectivamente, sendo os melhores resultados observados em receptoras da raça Romane pluríparas do que nas nulíparas da raça Suffolk. O número de ovulações, de embriões transferidos e o estádio de desenvolvimento embrionário causaram efeito sobre a taxa de sobrevivência embrionária. As melhores taxas de parição e de sobrevivência embrionária foram obtidas de receptoras com mais de duas ovulações que receberam dois embriões no estádio de blastocisto.

With the purpose of increase the breeding of Black Belly sheep breed at the experimental station of the Institut Scientifique de Recherche Agronomique (INRA), Bourges, France, thirty-two Black Belly sheep were super ovulated with swine FSH on the last three days of a progesterone treatment. After surgical collect 264 embryos transferable were recovered (8.2 ± 6.0/ donor) and 232 were transferred to 88 multiparous Romane sheep receptors and 23 nulliparous Suffolk sheep. Birth rate and survival rate were 83.6 and 63% respectively, though the results form multiparous Romane sheep receptors were better than from nulliparous Suffolk sheep. The ovulations number, transferred embryos and development stage had an effect on embryo survival rate. The best birth and embryo survival rates were from receptors that had more than two ovulations and had two embryos implanted at the stage of blastocyst.

Transferência de embriões como ferramenta para formação de rebanho experimental ovino e análise dos fatores que podem maximizar a multiplicação do plantel / Embryo transfer as a tool to experimental sheep flock formation and stock multiplication factors analyses

Visando ao aumento do plantel de ovinos da raça Black Belly na estação experimental do Institut Scientifique de Recherche Agronomique (INRA) de Bourges, França, foram utilizadas 32 ovelhas da raça Black Belly superovuladas com FSH suíno nos últimos três dias de tratamento progestágeno de 14 dias. Após coleta cirúrgica, obtiveram-se 264 embriões transferíveis (8,2 ± 6,0/doadoras), sendo transferidos 232 a 88 receptoras da raça Romane pluríparas e 23 da raça Suffolk nulíparas. As taxas de parição e de sobrevivência embrionária foram 83,6 e 63%, respectivamente, sendo os melhores resultados observados em receptoras da raça Romane pluríparas do que nas nulíparas da raça Suffolk. O número de ovulações, de embriões transferidos e o estádio de desenvolvimento embrionário causaram efeito sobre a taxa de sobrevivência embrionária. As melhores taxas de parição e de sobrevivência embrionária foram obtidas de receptoras com mais de duas ovulações que receberam dois embriões no estádio de blastocisto.(AU)

With the purpose of increase the breeding of Black Belly sheep breed at the experimental station of the Institut Scientifique de Recherche Agronomique (INRA), Bourges, France, thirty-two Black Belly sheep were super ovulated with swine FSH on the last three days of a progesterone treatment. After surgical collect 264 embryos transferable were recovered (8.2 ± 6.0/ donor) and 232 were transferred to 88 multiparous Romane sheep receptors and 23 nulliparous Suffolk sheep. Birth rate and survival rate were 83.6 and 63% respectively, though the results form multiparous Romane sheep receptors were better than from nulliparous Suffolk sheep. The ovulations number, transferred embryos and development stage had an effect on embryo survival rate. The best birth and embryo survival rates were from receptors that had more than two ovulations and had two embryos implanted at the stage of blastocyst.(AU)

Assessment of plasma profile of pregnancy-associated glycoprotein (PAG) in sheep with a heterologous (anti-caPAG55+59) RIA and its potential for diagnosing pregnancy.

The purpose of the present investigation was to generate pregnancy associated glycoprotein (PAG)-profiles throughout pregnancy in a heterogenous sample of sheep using a radioimmunoassay with a heterologous antibody (anti-caPAG(55+59), #708) and utilize them for the purpose of pregnancy detection. From 2 weeks after the introduction of males into the breeding herd until 4 weeks after parturition, weekly blood samples were collected from 66 pregnant and 25 non-pregnant ewes of various breeds. Between 3 and 5 weeks after conception, plasma PAG levels increased, remained almost stable until week 17, then continued to increase, culminating in a drastic surge during the last 2 weeks of pregnancy. By 4 weeks of gestation, the plasma PAG level exceeded the level typical for non-pregnant ewes by five standard deviations, permitting a reliable pregnancy diagnosis. Plasma PAG levels were higher in twin-bearing ewes than in ewes carrying a single lamb, differences getting more evident as pregnancy proceeded. Neither breed and parity of the mother nor sex and weight of lambs borne exerted a significant effect. The heterologous assay system utilizing a caprine antibody proved to deliver results that are more consistent and less depending on various variables than those used in other studies. It may be concluded that, at the present state of development, the assay provides a reliable means of diagnosing pregnancy in sheep from the 4th week after they have been bred onward.