Research articleEmbryo yield in dairy cattle after superovulation with Folltropin or Pluset

Two commercial FSH products were compared in a retrospective study on 3990 commercial superovulations and embryo recoveries in dairy heifers and cows. In addition, the 56-day nonreturn rate of 19,400 embryos produced with these two preparations was analyzed. Embryo collections were performed during a 16-year period from donors of Holstein and Ayrshire breeds. Folltropin (Vetoquinol S.A., Lure cedex, France) group (Group F) consisted of 2592 superovulations, of which 80% were performed on heifers and 20% on cows, and Pluset (Laboratorios Calier, S.A., Barcelona, Spain) group (Group P) of 1398 treatments, of which 66% and 34% were on heifers and cows, respectively. Total number of recovered structures, number of transferable embryos, and the proportion of unfertilized ova (UFO) and degenerated embryos were analyzed. Distribution of embryos into quality grades (1-3) and developmental stages (4-9) according to the IETS classification guidelines and means for each collection were evaluated. The proportion of low-responders having fewer than five corpora lutea and yielding fewer than five embryos or ova was investigated for each treatment. Group P yielded 1.1 recovered structures more than Group F (P < 0.001). Consequently, however, the number of transferable embryos did not differ among the groups, being 7.0 and 7.1 in Groups F and P, respectively. Instead, there was an increase in the number of UFO from 2.0 in Group F to 3.0 in Group P (P < 0.001). The quality of embryos and the developmental stages were similar between the groups and there was no difference in the proportion of low-responding donors in Group F and Group P. Also, there was no difference in the nonreturn rate after transfer of embryos originating from donors superovulated with Folltropin or Pluset. It was concluded that equal numbers of transferable embryos and pregnancies can be achieved with Folltropin and Pluset.