HORMONAL ASYNCHRONY AND EMBRYONIC DEVELOPMENT ( a )

Luteinizing hormone (LH), progesterone and estradiol profiles in peripheral blood serum were compared among parous and nonparous females with normal, abnormal or no e~ryonic development. Ho~nal profiles between parous and nonparous females of the same e~ryonic status did not differ and the data were combined. Estrous cycle length was longer (Pe.05) in parous (22.3k.4 days) than nonparous females (21.05.4 days). Females with normal developing embryos had a higher serum Progesterone concentration at Days 3 and 6 and a lower ratio of estradiol to progesterone than did females with abnormal embryonic development. Females with a normal embryo had higher (Pc.05) preovulatory LH peaks than females with abnormal development or no recovery of an oocyte or embryo (34.3k4.7, 11.826.8 and 13.3k2.5 nglml, respectively). The interval from onset of estrus to LX peak was 8.9*2.1, 13.7t3.7 and 13.5+ 6.2 hr for females with normal, abnormal or no recovery of an embryo. The lower LH peak, the longer interval from onset of estrus to LH peak, and lower progesterone concentration in peripheral blood serum in females with abnormal embryos or no recovery indicated that these females had a hormonal asynchrony. The hormonal asynchrony may produce an undesirable uterine environment for male and female gametes or embryos which resulted in fertilizatfon failure or embryonfc death. In the second experiment, more transferable embryos were obtained when superovulated females received prostaglandin Fna (PGFsa) intravenously rather than intramuscularly. A~inis~r~ng PGFsa intravenously rather than intramuscularly may have caused the demfse of the corpus luteum sooner and thereby produced a more normal uterine environment which allowed more embryos to develop normally. (4 The authors are grateful to Betty Petitjean and Bfll McKay for technical assistance, to Gary Peterson, Walt Green, John Siebrandt, Gabe Johnson, Becky Gerlach, Doug Weich~n and Dave Jansen for the care, breeding and bleeding of cattle, and to Cheryl Yates for stenographic work. Cooperation of the Nebraska AgrScultural Experdment Station, University of Nebraska, Lincoln is acknowledged. (b) Science and Education Administration, Agricultural Research. (c) Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the U. S. Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable. JANUARY 1982VOL.17NO.l 11