Data/hora: 13/06/2024 02:09:14

Biblioteca(s): | Embrapa Caprinos e Ovinos.
Data corrente: | 23/03/2005
Data da última atualização: | 18/03/2010
Autoria: | RAMILLA, M. J.; GEBBIE, F. E.; KING, M. E.; CAROLAN, C.; SINCLAIR, K. D.; WATT, R. G.; DOLMAN, C. F.; BECKERS, J. F.; ROBINSON, J. J.
Título: | The incidence of embryo and fetal loss following the transfer of in vitro-cultured sheep embryos.
Ano de publicação: | 1998
Fonte/Imprenta: | Theriogenology, v. 49, n. 1, p. 248, 1998.
Idioma: | Inglês
Notas: | Edição de proceedings Annual Conference of the International Embryo Transfer Society Marriott at Copley Place, Boston, USA, jan. 1998.
Conteúdo: | On Day 6 following a synchronised estrus, 120 Scottish Blackface ewes each received a single blastocyst-stage embryo produced by in vitro culture of zygotes harvested from their superovulated contemporaries 36 h after intrauterine insemination to a single SuffoIk gire. Four treatments in a 2 x 2 factorial design, co-culture (CoCult) vs synthetic oviductal fluid (SOF) supplemented with low (A) vs high (B) ammonia-producing bovine serum, were used to culture the embryos from the zygote to blastocyst stage. Ewes were pregnancy tested by ultra- sound scanning on Day 60 of gestation and those pregnant were scanned again before slaughter on Day 125. Weekly blood samples were taken from Day 26 onwards from 3 of the 6 replicates for radioimmunoassay determination of pregnancy-associated glycoprotein (oPAG) to diagnose early pregnancy and detect embryonic death (Ranilla et al, 1994, Theriogenology 42:537-545). ControI samples were taken from 6 ewes that each received an in vivo-produced blastocyst. Day 60 pregnancy rate was 45% (54/120). Pregnancy rate did not differ between gera (A 49%; B 42%) but was higher (Chi-square 6.73, P<0.01) for CoCult (59%) than SOF (35%), Table 1. Pregnancies lost (n = 6) between Days 60 and 125 of gestation were not associated with any causal agent. Based on elevated oPAG in plasma taken at Day 26, 66% (35/53) of ewes receiving in vitro-cultured embryos initiated a pregnancy compared with 6 of 6 (100%) controI ewes receiving an in vivo-produced embryo. Subsequent losses to Day 60 were 2 (33%), 4 (36%), 3 (25%) and 6 (25%) for CoCult-A, CoCult-B, SOF-A and SOF-B, respectively, vs zero for contraIs. There was no significant correlation between oPAG concentrations on Day 26 and the outcome of pregnancy. In conclusion, oPAG analysis showed that ~ 30% of ewes receiving in vitro-cultured embryos experienced pregnancy failure between Days 26 and 60, and the leveI of loss was similar for alI culture treatments.
Palavras-Chave: | Coleta de embrião; Morte embrionária.
Thesagro: | Ovino; Reprodução Animal; Transferência de Embrião.
Categoria do assunto: | --
Registro original: | Embrapa Caprinos e Ovinos (CNPC)
Exemplares: | CNPC - (17557-1) - ADC - AP - -- -  -  - v.49,p.248 - DIS