Recovery rates and embryo quality following dominant follicle ablation in superovulated cattle

To determine the association between dominant follicle ablation and the out come of a superovulatory regimen, two data sets were constructed from recor ds of 171 recoveries from non-ablated cows and 1214 recoveries from cows th at underwent follicular ablation prior to FSH treatment. Data set 1 include d all cows with 2 or more records (n = 1385). Data set 2 included paired da ta for 87 cows which had at least 2 records of both ablated and non-ablated superovulatory attempts. Dominant follicle ablation was performed by use o f transvaginal, ultrasound guided aspiration 48 hr prior to the start of FS H. The same FSH protocols were used for both ablated and nonablated cows. F or all cows (data set 1), more total ova/embryos were recovered from the ab lation group (12.1+/-0.3 vs 10.5+/-0.8; P=0.06). This difference could be a ccounted for by greater numbers of non-transferable embryos in the ablation group (6.5+/-0.2 vs 5.3+/-0.6; P > 0.01). For the paired data (data set 2) , greater numbers of total ova/embryos recovered from the ablation group (1 2.8+/-1.0 vs 9.7+/-0.7; P=0.01) could also be accounted for by higher numbe rs of nontransferable embryos in this group (7.8+/-0.8 vs 4.5+/-0.4; P > 0. 01). There were no differences between groups for high quality embryos, per cent cows producing no ova/embryos or percent cows producing no transferabl e embryos. These data support the premise that synchronization of follicula r waves following dominant follicle ablation increases total ova/embryo out put. However, the additional embryos were primarily nontranferable thereby negating potential economic gains. (C) 2000 by Elsevier Science Inc.