Lamb birth weight is affected by culture system utilized during in vitro pre-elongation development of ovine embryos

Abstract

It has previously been reported that ovine embryos cultured in Synthetic Oviduct Fluid medium supplemented with 20% human serum (SOF + HS) develop into lambs with a high birth weight. We have investigated this phenomenon by culturing ovine zygotes in SOF + HS or a serum free version of Synthetic Oviduct Fluid with BSA and amino acids (SOFaaBSA) in place of serum. Zygotes were either obtained from superovulated and naturally mated ewes or produced in vitro. Embryos were subsequently transferred to synchronized recipient ewes (n = 63). An additional group of ewes (n = 16) served as flock fertility and lambing controls. Development of zygotes to stages suitable for transfer (i.e., good to excel..