Since 2017 multiple ovulation (MO) and embryo transfer (ET) were used to save
endangered cow breeds in Latvia. The aim of this work was to analyse results to establish factors
influenced recipients’ pregnancy obtained up to now. Recipients age, induced (IRC) or native
reproductive cycle (NRC), level of estradiol (E2) and progesterone (P4) in recipients’ blood on
ET day, stage and quality of embryo, fresh or thawed embryo usage and person provided ET were
taken into account. Repeated artificial insemination (AI) had been provided in 19 (22.1%)
recipients before ET. Pregnancy was accepted in 23 out of 76 recipients (30.3%) until now.
Higher pregnancy results were obtained using fresh embryos (19 out of 53 (35.8%)) vs thawed
embryos (4 out of 23 (17.4%)), (P < 0.05). The IRC was more productive than NRC (P < 0.05).
The development stage, quality of embryos, E2 level were significant factors to reach pregnancy
(P < 0.05) but recipients age, P4 level and person provided ET did not influence the pregnancy
rate in the present study (P > 0.05). More successful pregnancies were reached using embryos
obtained from donors which had a higher glucose and cholesterol level in blood (P = 0.05). In
conclusion, our newly educated MOET team should gain their experience and results could be
improved using IRC in recipients, fresh embryos, and more attention could be paid to the donorcows management in order to reach more qualitative embryos. Somatic cell count in the donors’
milk could be one of the indicator to avoid unsuccessful embryo obtaining
