Table of Contents
ISRN Veterinary Science
Volume 2011, Article ID 257627, 4 pages
http://dx.doi.org/10.5402/2011/257627
Research Article

Time Exposure Period of Bovine Oocytes to Sperm in Relation to Embryo Development Rate and Quality

1Laboratory of Animal Reproduction, Veterinary School, Faculty of Natural Resources, Catholic University of Temuco, P.O. Box 4780000, Temuco, Chile
2Department of Animal Sciences, Faculty of Veterinary Sciences, Southern University of Chile, P.O. Box 5090000, Valdivia, Chile

Received 24 November 2010; Accepted 4 January 2011

Academic Editor: R. Gamble

Copyright Β© 2011 Marco Berland et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The objective of the study was to determine the effect of different bovine gamete coincubation times on fertilization and embryo development performance. In vitro matured COCs were co-incubated with sperm at a concentration of 1.5 × 106 spermatozoa/ml in TALP medium for 3 hours (T 3, 𝑛 = 3 6 2 ), 6 hours (T 6, 𝑛 = 3 5 8 ), or 18 hours (T 18, 𝑛 = 3 5 0 ). At the end of the coincubation period COCs from times 3 and 6 groups were post-incubated in a new well of fertilization medium without sperm for additional 15 and 12 h, respectively. Cumulus Oocyte Complexes from the T 18 were co-incubated with the sperm suspension for 18 hours. Presumptive zygotes were cultured for 9 days and embryo development was evaluated on days 2, 8, and 9. Thirty blastocysts from each group were stained and total number of nuclei was recorded. The mean (± SEM) percentages of zygotes to develop into ≥2 cell stage were 71.9 ± 5.0; 72.5 ± 5.3 and 81.2 ± 6.1 % for T 3, 6, and 18, respectively, on day 2 and they did not differ ( 𝑃 = . 3 ) among groups. The mean percentage of blastocysts developed on day 8 (25.6 ± 2.8; 24.2 ± 3.3; 28.4 ± 4.2 % for T 3, 6, and 18, resp.) did not differ ( 𝑃 = . 4 ) among groups. The total number of embryonic nuclei was greater ( 𝑃 < . 0 5 ) for the blastocysts produced from the shortest co-incubation time (T 3).