Bovine and ovine embryos exposed to a variety of unusual environments prior to the blastocyst stage have resulted in the development of unusually large offspring which can also exhibit a number of organ defects. In these animals, the increased incidence of difficult parturition and of fetal and neonatal losses has limited the large-scale use of in vitro embryo production technologies commonly u...

Multiple ovulation and embryo transfer (MOET) has the potential to increase the rates of genetic improvement in sheep. However, better realization of this potential requires a higher yield of transferable embryos. Thus we investigated some factors that may contribute to high embryo yield and quality under field conditions, as part of an ongoing MOET program. Comparison of the effects of 2 breed...

The developmental capacity of (a) single blastomeres of 4-cell embryos, (Jb) pairs of blastomeres of 8-cell embryos and (c) single blastomeres of 8-cell embryos was studied. The blastomeres were inserted into evacuated foreign zonae pellucidae, embedded in agar, transferred to ligated oviducts of dioestrous ewes, and recovered when their total age was 5-Jto 6̂ days. At lecovery the majority of e...

The developmental capacity of (a) single blastomeres of 4-cell embryos, (Jb) pairs of blastomeres of 8-cell embryos and (c) single blastomeres of 8-cell embryos was studied. The blastomeres were inserted into evacuated foreign zonae pellucidae, embedded in agar, transferred to ligated oviducts of dioestrous ewes, and recovered when their total age was 5-Jto 6̂ days. At lecovery the majority of e...

In the current study we investigated whether the developmental status of the two largest follicles (LF1 and LF2) at the time of administration of the first two doses (0 and 12 h) of FSH of a superovulatory treatment influences periovulatory events and embryo yields in sheep. A larger size of LF1 was negatively correlated with embryo recovery (r=-0.608 for 0 h and r=-523 for 12 h, p<0.05), ferti...

Transcriptomics and bioinformatics were used to investigate the potential interactions of undernutrition presence conceptus at time maternal recognition pregnancy on uterine immune system remodeling. Adult Rasa Aragonesa ewes allocated one two planes nutrition for 28 days: maintenance energy intake (control; 5 cyclic, 6 pregnant ewes) providing 7.8 MJ metabolisable 0.5 (undernourished; 7 3.9 pe...

introduction: to improve the development of embryo in vitro several attempts have been made, including the application of leukemia inhibitory factor (lif). this factor plays an important role in embryo development and has been shown to enhance in vitro development rate in sheep and mice. there is controversy regarding the effect of lif on the different stages of embryo development. the aim of t...

The relationship between nutrition and reproduction in sheep has been the subject of research in several international groups. This review will particularly focus on the effects of undernutrition on the potential causes of reproductive failure including abnormalities of the ovum or the embryo, luteal inadequacy and failure of the supply of progesterone to the uterus, or the mechanisms involved ...

BACKGROUND It has been proposed that preimplantation embryo viability during culture and following embryo transfer is associated with a 'quiet' metabolism. Viable embryos may be better equipped to contend with damage to the genome, transcriptome and proteome, or they may possess less damage than non-viable embryos. METHODS Much of the data for the quiet embryo hypothesis was obtained in the h...