In summary the ART is an important tool for conservation of endogenous species. These techniques include: artificial insemination, cryopreservation (freezing) of gametes or embryos, induction of multiple ovulations, embryo transfer, in vitro fertilization, sex determination of sperm or embryos, nuclear transfer, cloning, etc. The success of embryo transfer depends on management of donor and recipient animals, synchronization of estrus in donors and recipients, superovulation of donors, breeding (natural or artificial insemination), embryo collection and evaluation, transfer of embryo, and factors affecting survival of transferred embryos. The effect of nutrition (total protien, cholestrol, NEFA, BHB, AST) was studied in Merino ewes. All together 35 hungarian merino breed ewes, aged between 2 and 6 years and with an average weight of 62 kg were selected to use as donor or recipient animals to carry out the embryo transfer program and for determination of some metabolic parameters’ (BHB, karbamid, NEFA, total protein, cholesterol, AST) in peripheral blood level. Both in 2009 and in 2010, 1-1 experiment was carried out of the breeding season. In all the two experiments 12 and 23 animals were used as donor and recipient animals respectively. Although all the values we measured both in 2009 and 2010 were within the normal range, but the result showed that the ewes were quite defficient in energy in 2009 as compare to the ewes in 2010. Also the number of embryos and ova recovered were quite different between the two groups. As we set out the number of CL on both ovaries and number of embryos in Table 2. and Table 3. in 2009 the we got number of CL and number of embryos less than 2010, because ewes were energy defficient in 2009 and as result we got less number of CL and embryo similary there were 14 emberyos recovered in 2009 out of which only one embryo was tarnsferable as shown in Table 2. In contrary in 2010 the ewes were energy rich and as result we got more number of CL as well as embryos as compared to the group of ewes in 2009. Similarly there were 66 embryos recovered in 2010 out of which only 44 were transferable. Also it shows that the nutrition has significant affect on success of embryo transfer. In Table 2. and the numebr of CL on the right ovary was more than that on the left ovary following the PMSG treatment and it suggests that possibly, the right ovary responded PMSG better than the left ovary. Similar result was there in Table 3. except one left ovary which responded to PMSG better than that of the right ovary. The similar study carried out by (Casida et al, 1966; Scaramuzzi and Downing, 1997). In 2009, we measured significantly higher BHB values, although, the results had been within the normal range. There were no significant differences between the years, and NEFA values were within the normal range. In 2010, we measured significantly higher cholesterol values, although, the results had been within the normal range. There has been no significal difference in the level of AST between the two years, but the results showed us liver strain. In 2009, we measured significantly higher karbamid values, although, the results had been within the normal range. This suggests relative energy deficiency in the rumen. 60- 80 g/l is the TP normal range in sheep. In 2010, TP was significantly higher in the blood samples. Although all the values we measured both in 2009 and 2010 were within the normal range, the results showed, that in 2009 the ewes’ have been in relative energy deficiency. This energy deficincy did not appeared in any kind of symptoms, but had been enough to affect the success of the ET program.