1. W191 EMBRYO TRANSFER FOLLOWING TREATMENT OF CYSTIC OVARIES IN CATTLE C.E. Ferguson 1, F.M. LeMieux 1, D.J. Kesler 2, R.A. Godke 3 1 Department of Agriculture, McNeese State University, Lake Charles, LA 2 Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana, IL 3 Department of Animal Sciences, Louisiana State University, Baton Rouge, LA MATERIALS & METHODS A total of 16 cross-bred mature beef cows were utilized in this research experiment. All 16 cows were used to attempt to induced follicular cysts (figure 1., Cook et al. 1991). Within 28 days following last steroid administration to induce cysts, 8 of the 16 cows had developed a follicular cyst ≥ 24 mm for ≥ 7 days in the absence of a corpus luteum (figure 2). These 8 cows were then randomly divided into two groups with one group (n = 3) administered 100 mcg of GnRH and the control group (n = 3) administered a sham injection. Following treatments, all cows received two transferable quality IVF-derived embryos transferred ipsilateral to the luteinized cyst in treatment groups and one per horn in control cows (figure 3). These females were ultrasound to determine pregnancy status 22 days post-transfer. Figure 3. Experimental design for treatment group cows receiving 100 mcg GnRH and embryo transfer. Figure 2. Ultrasound images of induced follicular cysts (a) 30 mm follicular cyst, (b) 35 mm follicular cyst. ab OBJECTIVES The objective of this experiment was to determine if the interval from treatment to conception in beef cattle with induced follicular cysts could be reduced by utilizing GnRH treatment and embryo transfer. INTRODUCTION Historically, cystic ovaries occur at a rate of 6 to 19% in dairy cattle and < 10% in beef cattle. Although, these numbers may be low in some herds they can represent a substantial loss in overall animal production and economy. Often the time interval from treatment to conception can be several months or longer in some cattle and although routine treatment with GnRH or prostagladin can be effective, often multiple treatments may be necessary. Currently, no effective method of inducing pregnancy in cattle with follicular cysts exists. Figure 1. Design of experimental protocol for induction of follicular cyst in beef cattle. SUMMARY & CONCLUSION The resulting pregnancy established in this research project indicated that embryo transfer following GnRH treatment in cystic cattle may provide a valuable method of decreasing the time interval from treatment to conception. However, the luminal fluid accumulation resulting from the persistent follicular cysts must be addressed to make this a viable method of treatment for beef cattle with follicular cysts. RESULTS Prior to and following treatments with GnRH or Sham injection, 4 of the 6 cows (2 from treatment group and 2 from control group) had luminal fluid accumulation in the uterine horns (figure 2). The uteri of these cows resembled that of cattle in estrus. Prior to and following treatments with GnRH or Sham injection, 4 of the 6 cows (2 from treatment group and 2 from control group) had luminal fluid accumulation in the uterine horns (figure 2). The uteri of these cows resembled that of cattle in estrus. Approximately 30 days post-treatment one female from the treatment group was pregnant as determined via ultrasongraphy. The pregnant cow, as several others continued to retain large diameter follicles and uterine fluid for the duration of this experiment even in the presence of a corpus luteum (figure 4.) The large persistent follicle in the pregnant cow was contraleral to the CL bearing ovary. The pregnancy established in this research experiment was lost for unknown reasons after 45 days of gestation. Figure 4. Ultrasound images of (a) fluid accumulation in uterine horns in both treatment and control cows. And (b) 40 day pregnancy in treated- cystic cow and embryo transfer a b