To evaluate the effects of a commercially produced serum substitute on
the in vitro development of caprine embryos, registered Nubian doelin
gs were synchronized with norgestomet-impregnated implants (Synchromat
e-B(R): CEVA) and superovulated with descending doses of FSH-p(R) (Sch
ering). A total of 246 embryos was collected and placed in Tissue Cult
ure Medium 199 (TCM 199, Gibco Laboratories) containing Nu-Serum(R) (N
uS) at concentrations of 2.5%, 5.0%, 10%, or 20%. Control treatments c
onsisted of TCM 199 alone or TCM 199 plus 10% heat-inactivated fetal b
ovine serum (FBS). Embryos developed in all concentrations of NuS to t
he morula, blastocyst, and expanded blastocyst stages. The TCM 199 plu
s 10% NuS had significantly higher percentages of embryos developing t
o the expanded blastocyst stage than TCM 199 plus 10% FBS. Time to exp
anded blastocyst development in NuS was shorter than in the TCM 199 pl
us FBS. No stage-specific block to development was observed with embry
os collected and cultured in vitro for any of the treatments. These re
sults demonstrate that NuS, when compared to FBS, allowed a higher per
centage (P< 0.05) of caprine embryos to develop to the expanded blasto
cyst stage, thus providing a valuable substitute for FBS.