326 OPTIMIZING FREQUENCY OF FSH APPLICATION FOR SUPEROVULATORY TREATMENT IN CATTLE

Abstract

The aim of the study was to examine the influence of the application frequency of Pluset® (Calier, Spain) and Folltropin® (Vetrepharm, London, Ontario, Canada) on the results of embryo recovery in Simmental cattle. Moreover, pulsatility of LH concentrations in plasma should be studied before and after application of Pluset. FSH was given in a treatment of eight or four injections on four consecutive days starting between Days 9 and 13 of the estrous cycle. Luteolysis was induced by application of 500 μg Estrumate® (Essex Tierarznei, Munich, Germany), applied 72 and 84 h after the first FSH injection. Embryo recovery was performed non-surgically on Day 7 of the following estrous cycle. Heifers received either a total amount of 500 IU Pluset according to the International Standard for human urine FSH and LH (P1: 8 injections, n = 20; P2: 4 injections, n = 54) or 200 mg Folltropin according to NIH bFSH-B1 (F1: 8 injections, n = 117; F2: 4 injections, n = 60). Cows received either 550 IU Pluset (P3: 8 injections, n = 54; P4: 4 injections, n = 183) or 260 mg Folltropin (F3: 8 injections, n = 36; F4: 4 injections, n = 159). Altogether 8 heifers were bled throughout 8 h every 10 min on Days 9 and 12 (before and during stimulation with FSH). The samples were analyzed for LH by ECLIA (intra-assay coefficient of variation (VK) 6.4%, inter-assay VK 8.9%). The evaluation of the data was carried out with the procedure ‘GLM’ of the statistics software package SAS (SAS Institute, Inc., Cary, NC, USA) and PULSAR analysis. As a post hoc test Student's t-test was used. Significance was set at P = 0.05. Results of embryo recovery are shown in the table. Number of LH pulses in 8 h (LSM ± SE) was 2.3 ± 0.4 on Day 9 and 0.6 ± 0.4 on Day 12 (P < 0.05). We conclude that four injections of both FSH products can lead to results comparable with those reached with eight injections in a 12 hours interval. Therefore, the effort for superovulatory treatments can be reduced. However, it has to be considered that the portion of transferable embryos was reduced, partly significantly, after four FSH injections. This result was independent of the drug used. Table 1. Results of embryo recovery