
%0 Journal Article
%A Morton, K. M. 
%A Maxwell, W. M. C. 
%A Evans, G. 
%T 205. The effect of FSH concentration during IVM and gamete co-incubation length during IVF on the development of unstimulated prepubertal ewe oocytes
%J Reproduction, Fertility and Development
%D 2004/08/25
%V 16
%N 9
%P 205-205
%K 
%R https://doi.org/10.1071/SRB04ABS205
%U https://www.publish.csiro.au/paper/SRB04ABS205 
%X The developmental competence of prepubertal oocytes can be increased by the administration of gonadotrophins prior to oocyte collection (1)&#x003B; but this is not possible with abattoir-sourced oocytes, and modifications to the IVP system may increase in vitro development. Experiments were conducted to determine the effects of FSH concentration (10, 20 or 60 &#956;g mL-1) during IVM (5 replicates) and gamete co-incubation length (short: 2-3 h, long: 18-20 h) during IVF (6 replicates) on subsequent embryonic development. For both experiments ovaries were collected from prepubertal lambs (16-24 weeks) slaughtered at an abattoir and embryos produced in vitro (1). Data were analysed by chi-squared test. Oocyte cleavage at 48 hours post-insemination (hpi) was higher for oocytes matured in medium containing 20 (60/77&#x003B; 77.9%) and 60 (56/73&#x003B; 76.7%) than 10 &#956;g mL-1 (40/67&#x003B; 59.7%) FSH. Blastocyst formation (% cultured oocytes) on Day 7 (Day 0 = IVF) was higher for oocytes matured with 20 (31/77&semi; 40.3%) than 10 (16/67&#x003B; 23.9%) or 60 &#956;g mL-1 (20/73&#x003B; 27.4%). Oocyte cleavage at 48 hpi was reduced for short (36/57&#x003B; 63.2%) compared with long (49/55&#x003B; 89.1%) co-incubation, although blastocyst formation (% cultured oocytes&#x003B; Day 7) did not differ between groups (22/57&#x003B; 38.6% and 23/55&#x003B; 41.8%, respectively). These results demonstrate that increasing the FSH concentration above normal levels during IVM of prepubertal lamb oocytes improves development in vitro. Gamete co-incubation length did not influence the proportion of oocytes progressing to the blastocyst stage. (1) Morton et al. (2003) Proc. Soc. Reprod. Fert. P18. 
