Table 2. Effect of transferred cloned embryo number per surrogate on in vivo development of cloned embryos.

Number of embryos transferred	No. surrogates (transferred embryos)	No. pregnancy (%)	No. delivery (%)	No. piglets (mean ± SEM)	No. piglets alive (mean ± SEM)	Cloning efficiency (%)
101–150	19 (2475)	11 (57.90 ± 11.19)	10 (52.63 ± 11.60)	37 (1.95 ± 0.66)	26 (1.37 ± 0.46)	1.07 ± 0.29
151–200	22 (3820)	15 (68.18 ± 10.40)	13 (59.09 ± 10.78)	52 (2.36 ± 0.61)	36 (1.64 ± 0.42)	0.99 ± 0.27
201–250	16 (3540)	11 (68.75 ± 12.19)	10 (62.50 ± 12.64)	51 (3.19 ± 0.72)	30 (1.88 ± 0.50)	0.85 ± 0.32

No significant differences of in vivo development were observed among the examined numbers of cloned embryos transferred

The rates of pregnancy and delivery and the average numbers of piglets born and alive were based on the number of surrogates.

Cloning efficiency was calculated by total number of live cloned piglets/total number of transferred cloned embryos.