Abstract
The objective was to determine the effect of various cell types on the development of bovine embryos in vitro. Morulae were collected from beef and dairy cows 4 to 5 d after the onset of estrus (d 0). Embryos were randomly allocated to nine treatments: (1) microdrops of Ham's F-10 medium (HF-10) under paraffin oil (HF-10); (2) HF-10 over a substratum of collagen without paraffin oil (HF-10/clg); (3) HF-10 with bovine uterine fibroblasts grown on a collagen substratum (HF-10/clg-fib); (4) Minimal Essential Medium (MEM) without paraffin oil (MEM); (5) microdrops of MEM under paraffin oil (MiiM/oil); (6) MEM with bovine uterine fibroblasts (MEM/Buf); (7) MEM with bovine testicular fibroblasts (MEM/Btes); MEM exposed to uterine fibroblasts for 24 h to condition the medium (MEM/Con), and MEM with 1 mm cubes of bovine endometrial tissue (MEM/End). In all cases, media were supplemented with 10% (v/v) heat-treated fetal calf serum. Observations were made at 24 h intervals, with the stage of embryo development recorded. Morulae developed into expanded blastocysts more frequently (P<.05) in HF-10, MEM, MEM/oil, MEM/Buf, MEM/Btes and MEM/Con than in HF-10/clg, HF-10/clg-fib and MEM/End. More (P<.01) blastocysts hatched in MEM/Buf and MEM/Btes than in the other media. In addition, nine of 12 (MEM/Buf), eight of 11 (MEM/Btes) and two of two (HF-10/ clg-fib) hatched blastocysts attached to the fibroblast monolayers, an observation that was uncommon in treatments without cells. These data suggest that the co-culture of bovine embryos with bovine fibroblasts in a superior system for promoting embryo hatching and attachment in vitro. Copyright © 1982. American Society of Animal Science. Copyright 1982 by American Society of Animal Science.