Body dimensions and birth and organ weights of calves derived from in vitro produced embryos cultured with or without serum and oviduct epithelium cells

Body dimensions, birth and organ weights of calves derived from embryos pro duced in 2 in vitro culture systems (modified SOFaa with 20% cattle serum a nd co-cultured with oviduct-epithelium cells [IVPserum, n = 8], and modifie d SOFaa with 3 mg/mL PVA [IVPdefined, n = 6]) were compared with calves ori ginating from artificial insemination (AI, n = 85). Three additional IVP ca lves were included which had been vitrified as mature oocytes by the open p ulled straw (OPS) method, warmed, fertilized and cultured to the blastocyst stage in modified SOFaa with 5% cattle serum, then again OPS-vitrified and warmed prior to transfer (TVPops, n = 3). At birth, gestation length and b irth weights were registered for all calves. At 1 wk of age all 17 IVP and 7 of the AI calves were killed, and their body dimensions and organ weights recorded. Birth weight was higher for the IVPserum and IVPops calves than for AI control calves (kg +/- SEM: IVPserum 46.9 +/- 1.8, IVPops 50.6 +/- 2 .4, AI 41.8 +/- 0.8; P < 0.002). There was no difference between IVP and AI calves regarding gestation length and no effect of culture conditions on b ody dimensions or organ weights, except for longer hind legs in IVPdefined calves compared with AI calves (cm +/- SEM: IVPdefined 93 +/- 2, Al 87 +/- 2; P < 0.04). The IVPops calves had an increased liver weight compared with AI and the other IVP calves (g +/- SEM: IVPops 1,457 +/- 59; AI 1.117 +/- 37; IVPsenun 1,159 +/- 34; IVPdefined 1,073 +/- 39; P < 0.0003). It is conc luded that in vitro culture of bovine embryos in the presence of serum and oviduct epithelium cells increased birth weight but not organ weight and bo dy dimension in I-wk-old calves. However, vitrification of the ova as oocyt e and again as blastocysts increased birth weight and liver size. This poss ible effect of cryopreservation of oocytes on subsequent fetal development awaits further investigation. (C) 2000 by Elsevier Science Inc.