Influence of serum and hormones on bovine oocyte maturation and fertilization in vitro.
Three approaches were investigated for improvement of in vitro maturation (IVM), in vitro fertilization (IVF), and early embryonic development in cattle. These were: 1) Selection of oocytes, 2) medium supplementation with fetal calf serum (FCS) and cow sera (D0, D1, D10, and D20 to correspond with estrus, metestrus, diestrus, and proestrus, respectively), and 3) addition of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol-17 beta (E2) during maturation. Greater proportions (percentage) of oocytes initially selected for their compact cumulus cells completed IVM and IVF when compared to unselected oocytes (P less than .05). Proportions (percentage) of selected oocytes that matured and cleaved after in vitro insemination according to serum type used for IVM were: FCS: 110/175 (62.9%) and 37/110 (33.6%) and D0: 130/145 (89.7%) and 52/130 (40.0%); D1 127/130 (97.7%) and 41/127 (32.3%); D10 95/98 (96.9%) and 35/95 (36.8%); D20:113/116 (97.4%) and 49/113 (43.4%). A higher proportion (P less than .05) of embryos resulting from the D20 group reached four- and eight-cell stages. In FCS-supplemented maturation media with no hormones added during maturation (control), results of IVM and IVF were 157/265 (59.2%) and 39/157 (24.8%), respectively. With E2 (1 microgram/ml) and FSH (5 micrograms/ml), comparable results were 189/215 (87.9%) and 71/189 (37.6%); with E2 (1 microgram/ml) plus LH (10 micrograms/ml), 280/327 (85.6%) and 111/280 (39.6%). Added hormones improved IVM results (P less than .05) and, when FSH or LH was added with E2, in vitro development to four- and eight-cell stages was markedly enhanced (P less than .05). Selection of oocytes, D20 serum, and added E2 and FSH or LH for IVM improved in vitro development of bovine embryos after IVF.
Younis
A I
AI
Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens 30602.
Brackett
B G
BG
Fayrer-Hosken
R A
RA
D000818:Animals; D002417:Cattle; D002970:Cleavage Stage, Ovum / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D009866:Oogenesis / Q000187:drug effects*; D012710:Serum Albumin, Bovine / Q000494:pharmacology*
D003470:Culture Media; D012710:Serum Albumin, Bovine; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone