Longitudinal Study of Reproductive Performance of Female Cattle Produced by Somatic Cell Nuclear Transfer

Abstract

The objective of this study was to determine whether or not reproductive performance in cattle produced by somatic cell nuclear transfer (SCNT) is significantly different from that of their genetic donors. To address this question, we directed two longitudinal studies using different embryo production procedures: (1) superovulation followed by artificial insemination (AI) and embryo collection and (2) ultrasound-guided ovum pick-up followed by in vitro fertilization (OPU-IVF). Collectively, these two studies represent the largest data set available for any species on the reproductive performance of female clones and their genetic donors as measured by their embryo production outcomes in commercial embryo production program. The large-scale study described herein was conducted over a six-year period of time and provides a unique comparison of 96 clones to the 40 corresponding genetic donors. To our knowledge, this is the first longitudinal study on the reproductive performance of cattle clones using OPU-IVF. With nearly 2,000 reproductive procedures performed and more than 9,200 transferable embryos produced, our observations show that the reproductive performance of cattle produced by SCNT is not different compared to their genetic donors for the production of transferable embryos after either AI followed by embryo collection (P = 0.77) or OPU-IVF (P = 0.97). These data are in agreement with previous reports showing that the reproductive capabilities of cloned cattle are equal to that of conventionally produced cattle. In conclusion, results of this longitudinal study once again demonstrate that cloning technology, in combination with superovulation, AI and embryo collection or OPU-IVF, provides a valuable tool for faster dissemination of superior maternal genetics.

Artificial cloning of domestic animals

“…A large-scale project involving 96 cow clones and 40 corresponding genetic donors, as comparative controls, was carried out over a 6-y period. In this longitudinal study, Polejaeva et al (65) determined that the ability of clones to produce transferrablequality embryos after artificial insemination or in vitro embryo production was not different from that of their genetic comparatives that had been produced through normal breeding practices. Other work has focused on the health of clones: these studies suggest that clones that survive the critical neonatal period are generally normal physiologically.…”

Differences during the first lactation between cows cloned by somatic cell nuclear transfer and noncloned cows

“…Healthy cloned cows obtained through nuclear transfer from a defined nuclear donor cell line (Liu et al, 2013) are presumed to display limited genetic differences (Hanada et al, 2005). However, several reports have described some phenotypic variability between clones from a given nuclear donor cell line (Yonai et al, 2005), most likely due to environmental influences on the cloned cows, and cloned cattle achieve reproductive performance similar to that of noncloned ones (Polejaeva et al, 2013).…”

The mammalian preimplantation embryo: Its role in the environmental programming of postnatal health and performance

“…Nevertheless, from a livestock product point of view this finding is relevant as late onset of puberty is not compatible with a low age at first calving needed to achieve a good lifetime productivity in dairy cattle systems (Wathes et al, 2014). Cloned heifers and cows also seem to have a similar ability to produce preimplantation embryos either by MOET or IVEP when compared to AI-conceived controls (Polejaeva et al, 2014).…”